Author: "Dutton, G. S" - Searchworks@Jio Institute Digital Library Search Results

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154 results on '"Dutton, G. S"'

1. Increase in CFC-11 emissions from eastern China based on atmospheric observations

Author: Rigby, M., Park, S., Saito, T., Western, L. M., Redington, A. L., Fang, X., Henne, S., Manning, A. J., Prinn, R. G., Dutton, G. S., Fraser, P. J., Ganesan, A. L., Hall, B. D., Harth, C. M., Kim, J., Kim, K.-R., Krummel, P. B., Lee, T., Li, S., Liang, Q., Lunt, M. F., Montzka, S. A., Mühle, J., O’Doherty, S., Park, M.-K., Reimann, S., Salameh, P. K., Simmonds, P., Tunnicliffe, R. L., Weiss, R. F., Yokouchi, Y., and Young, D.
Published: 2019
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2. A 350-year atmospheric history for carbonyl sulfide inferred from Antarctic firn air and air trapped in ice

Author: Montzka, S. A, Aydin, M., Butler, J. H., Battle, M., Saltzman, E. S., Dutton, G. S., Hall, B. D., Clarke, A. D., Mondeel, D., and Elkins, J. W.
Subjects: aerosol, atmospheric chemistry, carbonyl compound, chemical composition, ice crystal, mixing ratio, trace gas, Antarctica, Arctic and Antarctic, Siple Dome, West Antarctica, world
Abstract: Carbonyl sulfide (COS) and other trace gases were measured in firn air collected near South Pole (89.98°S) and from air trapped in ice at Siple Dome, Antarctica (81.65°S). The results, when considered with ambient air data and previous ice core measurements, provide further evidence that atmospheric mixing ratios of COS over Antarctica between 1650 and 1850 A.D. were substantially lower than those observed today. Specifically, the results suggest annual mean COS mixing ratios between 300 and 400 pmol mol−1 (ppt) during 1650–1850 A.D. and increases throughout most of the twentieth century. Measurements of COS in modern air and in the upper layers of the firn at South Pole indicate ambient, annual mean mixing ratios between 480 and 490 ppt with substantial seasonal variations. Peak mixing ratios are observed during austral summer in ambient air at South Pole and Cape Grim, Tasmania (40.41°S). Provided COS is not produced or destroyed in firn, these results also suggest that atmospheric COS mixing ratios have decreased 60–90 ppt (10–16%) since the 1980s in high latitudes of the Southern Hemisphere. The history derived for atmospheric mixing ratios of COS in the Southern Hemisphere since 1850 is closely related to historical anthropogenic sulfur emissions. The fraction of anthropogenic sulfur emissions released as COS (directly or indirectly) needed to explain the secular changes in atmospheric COS over this period is 0.3–0.6%.
Published: 2004

3. Quantifying Transport between the Tropical and Mid-Latitude Lower Stratosphere

Author: Volk, C. M., Elkins, J. W., Fahey, D. W., Salawitch, R. J., Dutton, G. S., Gilligan, J. M., Proffitt, M. H., Loewenstein, M., Podolske, J. R., Minschwaner, K., Margitan, J. J., and Chan, K. R.
Published: 1996

4. The diurnal variation of hydrogen, nitrogen, and chlorine radicals: Implications for the heterogeneous production of HNO 2

Author: Salawitch, R. J, Wofsy, S. C, Wennberg, P. O, Cohen, R. C, Anderson, J. G, Fahey, D. W, Gao, R. S, Keim, E. R, Woodbridge, E. L, Stimpfle, R. M, Koplow, J. P, Kohn, D. W, Webster, C. R, May, R. D, Pfister, L., Gottlieb, E. W, Michelsen, H. A, Yue, G. K, Prather, M. J, Wilson, J. C, Brock, C. A, Jonsson, H. H, Dye, J. E, Baumgardner, D., Proffitt, M. H, Loewenstein, M., Podolske, J. R, Elkins, J. W, Dutton, G. S, Hintsa, E. J, Dessler, A. E, Weinstock, E. M, Kelly, K. K, Boering, K. A, Daube, B. C, Chan, K. R, and Bowen, S. W
Subjects: environmental chambers, peroxynitric acid, stratosphere
Abstract: In situ measurements of hydrogen, nitrogen, and chlorine radicals obtained through sunrise and sunset in the lower stratosphere during SPADE are compared to results from a photochemical model constrained by observed concentrations of radical precursors and environmental conditions. Models allowing for heterogeneous hydrolysis of N2O5 on sulfate aerosols agree with measured concentrations of NO, NO2, and ClO throughout the day, but fail to account for high concentrations of OH and HO2 observed near sunrise and sunset. The morning burst of [OH] and [HO2] coincides with the rise of [NO] from photolysis of NO2, suggesting a new source of HOxthat photolyzes in the near UV (350 to 400 nm) spectral region. A model that allows for the heterogeneous production of HNO2 results in an excellent simulation of the diurnal variations of [OH] and [HO2].
Published: 1994

5. An Examination of the Inorganic Chlorine Budget in the Lower Stratosphere

Author: Bonne, G. P, Stimpfle, R. M, Cohen, R. C, Voss, P. B, Perkins, K. K, Anderson, J. G, Salawitch, R. J, Elkins, J. W, Dutton, G. S, and Jucks, K. W
Subjects: Geophysics
Abstract: We use the first simultaneous in situ measurements of ClONO2, ClO, and HCl acquired using the NASA ER-2 aircraft during the Photochemistry of Ozone Loss in the Arctic Region in Summer (POLARIS) mission to test whether these three compounds quantitatively account for total inorganic chlorine (Cly) in the lower stratosphere in 1997. We find (ClO + ClONO2 + HCl)/Cly = 0.92 +/- 0.10, where Cly is inferred from in situ measurements of organic chlorine source gases. These observations are consistent with our current understanding of the budget and partitioning of Cly in the lower stratosphere. We find no evidence in support of missing inorganic chlorine species that compose a significant fraction of Cly. We apply the analysis to earlier ER-2 observations dating from 1991 to investigate possible causes of previously observed discrepancies in the inorganic chlorine budget. Using space shuttle, satellite, balloon, and aircraft measurements in combination with ER-2 data, we find that the discrepancy is unlikely to have been caused by missing chlorine species or an error in the photolysis rate of chlorine nitrate. We also find that HCl/Cly is not significantly controlled by aerosol surface area density in the lower stratosphere.
Published: 2000
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6. Dehydration and Denitrification in the Arctic Polar Vortex During the 1995-1996 Winter

Author: Hintsa, E. J, Newman, P. A, Jonsson, H. H, Webster, C. R, May, R. D, Herman, R. L, Lait, L. R, Schoeberl, M. R, Elkins, J. W, Wamsley, P. R, Dutton, G. S, Bui, T. P, Kohn, D. W, and Anderson, J. G
Subjects: Geophysics
Abstract: Dehydration of more than 0.5 ppmv water was observed between 18 and 19 km (0-450-465 K) at the edge of the Arctic polar vortex on February 1, 1996. More than half the reactive nitrogen (NO(y)) had also been removed, with layers of enhanced NO(y) at lower altitudes. Back trajectory calculations show that air parcels sampled inside the vortex had experienced temperatures as low as 188 K within the previous 12 days, consistent with a small amount of dehydration. The depth of the dehydrated layer (approximately 1 km) and the fact that trajectories passed through the region of ice saturation in one day imply selective growth of a small fraction of particles to sizes large enough (>10 microns) to be irreversibly removed on this timescale. Over 25% of the Arctic vortex in a 20-30 K range of 0 is estimated to have been dehydrated in this event.
Published: 1998
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7. Distribution of Halon-1211 in the Upper Troposphere and Lower Stratosphere and the 1994 Total Bromine Budget

Author: Wamsley, P. R, Elkins, J. W, Fahey, D. W, Dutton, G. S, Volk, C. M, Myers, R. C, Montzka, S. A, Butler, J. H, Clarke, A. D, and Fraser, P. J
Subjects: Environment Pollution
Abstract: We report here on the details of the first, in situ, real-time measurements of H-1211 (CBrClF2) and sulfur hexafluoride (SF6) mixing ratios in the stratosphere up to 20 km. Stratospheric air was analyzed for these gases and others with a new gas chromatograph, flown aboard a National Aeronautics and Space Administration ER-2 aircraft as part of the Airborne Southern Hemisphere Ozone Experiment/Measurements for Assessing the Effects of Stratospheric Aircraft mission conducted in 1994. The mixing ratio of SF6, with its nearly linear increase in the troposphere, was used to estimate the mean age of stratospheric air parcels along the ER-2 flight path. Measurements of H-1211 and mean age estimates were then combined with simultaneous measurements of CFC-11 (CCl3F), measurements of brominated compounds in stratospheric whole air samples, and records of tropospheric organic bromine mixing ratios to calculate the dry mixing ratio of total bromine in the lower stratosphere and its partitioning between organic and inorganic forms. We estimate that the organic bromine-containing species were almost completely photolyzed to inorganic species in the oldest air parcels sampled. Our results for inorganic bromine are consistent with those obtained from a photochemical, steady state model for stratospheric air parcels with CFC- I I mixing ratios greater than 150 ppt. For stratospheric air parcels with CFC-11 mixing ratios less than 50 ppt (mean age greater than or equal to 5 years) we calculate inorganic bromine mixing ratios that are approximately 20% less than the photo-chemical, steady state model. There is a 20% reduction in calculated ozone loss resulting from bromine chemistry in old air relative to some previous estimates as a result of the lower bromine levels.
Published: 1998
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8. A Comparison of Measurements from ATMOS and Instruments Aboard the ER-2 Aircraft: Halogenated Gases

Author: Chang, A. Y, Salawitch, R. J, Michelsen, H. A, Gunson, M. R, Abrams, M. C, Zander, R, Rinsland, C. P, Elkins, J. W, Dutton, G. S, Volk, C. M, Webster, C. R, May, R. D, Fahey, D. W, Gao, R.-S, and Loewenstein, M
Subjects: Geophysics
Abstract: We compare volume mixing ratio profiles of N2O, CFC-11, CFC-12, CCl4, SF6, and HCl in the mid-latitude lower stratosphere measured by the ATMOS Fourier transform spectrometer on the ATLAS-3 Space Shuttle Mission with in situ measurements acquired from the NASA ER-2 aircraft during Nov. 1994. Good agreement is found between ATMOS and in situ correlations of [CFC-11], [CFC-12], and [SF6] with [N2O]. ATMOS measurements of [CCl4] are 15% high compared to ER-2 data, but agree within the systematic uncertainties. ATMOS observations of [HCl] vs [N2O] are within approximately 10% of ER-2 data for [HCl] > 1 ppbv, but exceed in situ measurements by larger fractional amounts for smaller [HCl]. ATMOS measurements of [ClONO2] agree well with values inferred from in situ observations of [ClO], [NO], and [O3]. The sum of [HCl] and [ClONO2] observed by ATMOS, supplemented by a minor contribution from [ClO] estimated with a photochemical model, is consistent with the levels of inorganic chlorine inferred from in situ measurements of chlorine source gases.
Published: 1996
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9. A Comparison of Measurements from ATMOS and Instruments Aboard the ER-2 Aircraft: Tracers of Atmospheric Transport

Author: Stiller, G. P, Newchurch, M. J, Manney, G. L, Irion, F. W, Goldman, A, Abbas, M. M, Chan, K. R, Kohn, D. W, Stimpfle, R. M, Podolske, J. R, Lowenstein, M, Fahey, D. W, Volk, C. M, Dutton, G. S, Elkins, J. W, May, R. D, Webster, C. R, Rinsland, C. P, Zander, R, Abrams, M. C, Gunson, M. R, Michelsen, H. A, Salawitch, R. J, and Chang, A. Y
Abstract: We have compared volume mixing ration profiles of N2 O, CFC-11, CFC-12, CCI4 , SF6, and HCI measured for the mid-latitude stratosphere by the ATMOS Fourier transform spectrometer during the ATLAS-3 Space Shuttle mission of NOvember 1994 with in situ measurements acquired aboard the NASA ER-2 aircraft during the same time period.
Published: 1996

10. A Comparison of Measurements from ATMOS and Instruments Aboard the ER-2 Aircraft: Tracers of Atmospheric Transport

Author: Chang, A. Y, Salawitch, R. J, Michelsen, H. A, Gunson, M. R, Abrams, M. C, Zander, R, Rinsland, C. P, Webster, C. R, May, R. D, Elkins, J. W, Dutton, G. S, Volk, C. M, Fahey, D. W, Lowenstein, M, Podolske, J. R, Stimpfle, R. M, Kohn, D. W, Chan, K. R, Abbas, M. M, Goldman, A, Irion, F. W, Manney, G. L, Newchurch, M. J, and Stiller, G. P
Published: 1996

11. A Comparison of Measurements from ATMOS and Instruments Aboard the ER-2 Aircraft: Halogenated Gases

Author: Stiller, G. P, Newchurch, M. J, Manney, G. L, Irion, F. W, Goldman, A, Abbas, M. M, Chan, K. R, Margitan, J. J, Proffitt, M. H, Kohn, D. W, Stimpfle, R. M, Podolske, J. R, Lowenstein, M, Gao, R. S, Fahey, D. W, May, R. D, Webster, C. R, Volk, C. M, Dutton, G. S, Elkins, J. W, Rinsland, C. P, Zander, R, Abrams, M. C, Gunson, M. R, Michelsen, H. A, Salawitch, R. J, and Chang, A. Y
Abstract: We compare the mixing rations of N2O, CFC-11, CFC-12, CCI4, SF6, and HCI in the mid-latitude stratosphere measured by the ATMOS Fourier transform spectrometer with in situ measurements acquired aboard the NASA ER-2 aircraft during November 1994. Good agreement is found between ATMOS and in situ correlations of CFC-11, CFC-12, and SF6 with N2O. ATMOS observations of CCI4 are approx. 15 percent higher than the ER-2 data, but within the systematic uncertainties.
Published: 1996

12. An examination of the total hydrogen budget of the lower stratosphere

Author: Dessler, A. E, Weinstock, E. M, Hintsa, E. J, Anderson, J. G, Webster, C. R, May, R. D, Elkins, J. W, and Dutton, G. S
Subjects: Geophysics
Abstract: We analyze the hydrogen budget of the lower stratosphere using simultaneous in situ measurements of northern hemispheric water vapor (H2O) and methane (CH4) obtained during the spring Stratospheric Photochemistry, Aerosols, and Dynamics Expedition (SPADE), as well as previously published in situ H2 data. Based on this data, we conclude that approximately two H2O molecules are produced for each CH4 molecule destroyed. This implies that H2 production from CH4 oxidation is balanced by H2 oxidation. The uncertainty in this analysis is greatly reduced by the use of multiple data sets. Additionally, we infer that, on an annual and global average, H2O enters the stratosphere with a mixing ratio of 4.2 +/- 0.5 ppmv, and that the quasi-conserved quantity 2 x CH4 + H2O has a value of 7.6 +/- 0.6 ppmv in these northern hemishere air parcels (where xi denotes the mixing ratio of the constituent xi).
Published: 1994
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13. State of the climate in 2016

Author: Aaron-Morrison, A. P., Ackerman, S. A., Adams, N. G., Adler, R. F., Albanil, A., Alfaro, E. J., Allan, R., Alves, L. M., Amador, J. A., Andreassen, L. M., Arendt, A., Arévalo, J., Arndt, D. S., Arzhanova, N. M., Aschan, M. M., Azorin-Molina, C., Banzon, V., Bardin, M. U., Barichivich, J., Baringer, M. O., Barreira, S., Baxter, S., Bazo, J., Becker, A., Bedka, K. M., Behrenfeld, M. J., Bell, G. D., Belmont, M., Benedetti, A., Bernhard, G., Berrisford, P., Berry, D. I., Bettolli, M. L., Bhatt, U. S., Bidegain, M., Bill, B. D., Billheimer, S., Bissolli, P., Blake, E. S., Blunden, J., Bosilovich, M. G., Boucher, O., Boudet, D., Box, J. E., Boyer, T., Braathen, G. O., Bromwich, D. H., Brown, R., Bulygina, O. N., Burgess, D., Calderón, B., Camargo, S. J., Campbell, J. D., Cappelen, J., Carrasco, G., Carter, B. R., Chambers, D. P., Chandler, E., Christiansen, H. H., Christy, J. R., Chung, D., Chung, E. S., Cinque, K., Clem, K. R., Coelho, C. A., Cogley, J. G., Coldewey-Egbers, M., Colwell, S., Cooper, O. R., Copland, L., Cosca, C. E., Cross, J. N., Crotwell, M. J., Crouch, J., Davis, S. M., Eyto, E., Jeu, R. A. M., Laat, J., Degasperi, C. L., Degenstein, D., Demircan, M., Derksen, C., Destin, D., Di Girolamo, L., Di Giuseppe, F., Diamond, H. J., Dlugokencky, E. J., Dohan, K., Dokulil, M. T., Dolgov, A. V., Dolman, A. J., Domingues, C. M., Donat, M. G., Dong, S., Dorigo, W. A., Dortch, Q., Doucette, G., Drozdov, D. S., Ducklow, H., Dunn, R. J. H., Durán-Quesada, A. M., Dutton, G. S., Ebrahim, A., Elkharrim, M., Elkins, J. W., Espinoza, J. C., Etienne-Leblanc, S., Evans, T. E., Famiglietti, J. S., Farrell, S., Fateh, S., Fausto, R. S., Fedaeff, N., Feely, R. A., Feng, Z., Fenimore, C., Fettweis, X., Fioletov, V. E., Flemming, J., Fogarty, C. T., Fogt, R. L., Folland, C., Fonseca, C., Fossheim, M., Foster, M. J., Fountain, A., Francis, S. D., Franz, B. A., Frey, R. A., Frith, S. M., Froidevaux, L., Ganter, C., Garzoli, S., Gerland, S., Gobron, N., Goldenberg, S. B., Gomez, R. S., Goni, G., Goto, A., Grooß, J. U., Gruber, A., Guard, C. C., Gugliemin, M., Gupta, S. K., Gutiérrez, J. M., Hagos, S., Hahn, S., Haimberger, L., Hakkarainen, J., Hall, B. D., Halpert, M. S., Hamlington, B. D., Hanna, E., Hansen, K., Hanssen-Bauer, I., Harris, I., Heidinger, A. K., Heikkilä, A., Heil, A., Heim, R. R., Hendricks, S., Hernández, M., Hidalgo, H. G., Hilburn, K., Ho, S. P. B., Holmes, R. M., Hu, Z. Z., Huang, B., Huelsing, H. K., Huffman, G. J., Hughes, C., Hurst, D. F., Ialongo, I., Ijampy, J. A., Ingvaldsen, R. B., Inness, A., Isaksen, K., Ishii, M., Jevrejeva, S., Jiménez, C., Jin, X., Johannesen, E., John, V., Johnsen, B., Johnson, B., Johnson, G. C., Jones, P. D., Joseph, A. C., Jumaux, G., Kabidi, K., Kaiser, J. W., Kato, S., Kazemi, A., Keller, L. M., Kendon, M., Kennedy, J., Kerr, K., Kholodov, A. L., Khoshkam, M., Killick, R., Kim, H., Kim, S. J., Kimberlain, T. B., Klotzbach, P. J., Knaff, J. A., Kobayashi, S., Kohler, J., Korhonen, J., Korshunova, N. N., Kovacs, K. M., Kramarova, N., Kratz, D. P., Kruger, A., Kruk, M. C., Kudela, R., Kumar, A., Lakatos, M., Lakkala, K., Lander, M. A., Landsea, C. W., Lankhorst, M., Lantz, K., Lazzara, M. A., Lemons, P., Leuliette, E., L’heureux, M., Lieser, J. L., Lin, I. I., Liu, H., Liu, Y., Locarnini, R., Loeb, N. G., Lo Monaco, C., Long, C. S., López Álvarez, L. A., Lorrey, A. M., Loyola, D., Lumpkin, R., Luo, J. J., Luojus, K., Lydersen, C., Lyman, J. M., Maberly, S. C., Maddux, B. C., Malheiros Ramos, A., Malkova, G. V., Manney, G., Marcellin, V., Marchenko, S. S., Marengo, J. A., Marra, J. J., Marszelewski, W., Martens, B., Martínez-Güingla, R., Massom, R. A., Mata, M. M., Mathis, J. T., May, L., Mayer, M., Mazloff, M., Mcbride, C., Mccabe, M. F., Mccarthy, M., Mcclelland, J. W., Mcgree, S., Mcvicar, T. R., Mears, C. A., Meier, W., Meinen, C. S., Mekonnen, A., Menéndez, M., Mengistu Tsidu, G., Menzel, W. P., Merchant, C. J., Meredith, M. P., Merrifield, M. A., Metzl, N., Minnis, P., Miralles, D. G., Mistelbauer, T., Mitchum, G. T., Monselesan, D., Monteiro, P., Montzka, S. A., Morice, C., Mote, T., Mudryk, L., Mühle, J., Mullan, A. B., Nash, E. R., Naveira-Garabato, A. C., Nerem, R. S., Newman, P. A., Nieto, J. J., Noetzli, J., O’neel, S., Osborn, T. J., Overland, J., Oyunjargal, L., Parinussa, R. M., Park, E. H., Parker, D., Parrington, M., Parsons, A. R., Pasch, R. J., Pascual-Ramírez, R., Paterson, A. M., Paulik, C., Pearce, P. R., Pelto, M. S., Peng, L., Perkins-Kirkpatrick, S. E., Perovich, D., Petropavlovskikh, I., Pezza, A. B., Phillips, D., Pinty, B., Pitts, M. C., Pons, M. R., Porter, A. O., Primicerio, R., Proshutinsky, A., Quegan, S., Quintana, J., Rahimzadeh, F., Rajeevan, M., Randriamarolaza, L., Razuvaev, V. N., Reagan, J., Reid, P., Reimer, C., Rémy, S., Renwick, J. A., Revadekar, J. V., Richter-Menge, J., Riffler, M., Rimmer, A., Rintoul, S., Robinson, D. A., Rodell, M., Rodríguez Solís, J. L., Romanovsky, V. E., Ronchail, J., Rosenlof, K. H., Roth, C., Rusak, J. A., Sabine, C. L., Sallée, J. B., Sánchez-Lugo, A., Santee, M. L., Sawaengphokhai, P., Sayouri, A., Scambos, T. A., Schemm, J., Schladow, S. G., Schmid, C., Schmid, M., Schmidtko, S., Schreck, C. J., Selkirk, H. B., Send, U., Sensoy, S., Setzer, A., Sharp, M., Shaw, A., Shi, L., Shiklomanov, A. I., Shiklomanov, N. I., Siegel, D. A., Signorini, S. R., Sima, F., Simmons, A. J., Smeets, C. J. P. P., Smith, S. L., Spence, J. M., Srivastava, A. K., Stackhouse, P. W., Stammerjohn, S., Steinbrecht, W., Stella, J. L., Stengel, M., Stennett-Brown, R., Stephenson, T. S., Strahan, S., Streletskiy, D. A., Sun-Mack, S., Swart, S., Sweet, W., Talley, L. D., Tamar, G., Tank, S. E., Taylor, M. A., Tedesco, M., Teubner, K., Thoman, R. L., Thompson, P., Thomson, L., Timmermans, M. L., Maxim Timofeyev, Tirnanes, J. A., Tobin, S., Trachte, K., Trainer, V. L., Tretiakov, M., Trewin, B. C., Trotman, A. R., Tschudi, M., As, D., Wal, R. S. W., A, R. J., Schalie, R., Schrier, G., Werf, G. R., Meerbeeck, C. J., Velicogna, I., Verburg, P., Vigneswaran, B., Vincent, L. A., Volkov, D., Vose, R. S., Wagner, W., Wåhlin, A., Wahr, J., Walsh, J., Wang, C., Wang, J., Wang, L., Wang, M., Wang, S. H., Wanninkhof, R., Watanabe, S., Weber, M., Weller, R. A., Weyhenmeyer, G. A., Whitewood, R., Wijffels, S. E., Wilber, A. C., Wild, J. D., Willett, K. M., Williams, M. J. M., Willie, S., Wolken, G., Wong, T., Wood, E. F., Woolway, R. I., Wouters, B., Xue, Y., Yamada, R., Yim, S. Y., Yin, X., Young, S. H., Yu, L., Zahid, H., Zambrano, E., Zhang, P., Zhao, G., Zhou, L., Ziemke, J. R., Love-Brotak, S. E., Gilbert, K., Maycock, T., Osborne, S., Sprain, M., Veasey, S. W., Ambrose, B. J., Griffin, J., Misch, D. J., Riddle, D. B., Young, T., Macias Fauria, M, Blunden, J, Arndt, D, Earth and Climate, Faculty of Earth and Life Sciences, Clinical Developmental Psychology, Climate Change and Landscape Dynamics, and Molecular Cell Physiology
Subjects: Meteor (satellite), Atmospheric Science, 010504 meteorology & atmospheric sciences, 0208 environmental biotechnology, 02 engineering and technology, 01 natural sciences, 020801 environmental engineering, Geography, 13. Climate action, Climatology, SDG 13 - Climate Action, SDG 14 - Life Below Water, 0105 earth and related environmental sciences
Abstract: In 2016, the dominant greenhouse gases released into Earth's atmosphere-carbon dioxide, methane, and nitrous oxide-continued to increase and reach new record highs. The 3.5 +/- 0.1 ppm rise in global annual mean carbon dioxide from 2015 to 2016 was the largest annual increase observed in the 58-year measurement record. The annual global average carbon dioxide concentration at Earth's surface surpassed 400 ppm (402.9 +/- 0.1 ppm) for the first time in the modern atmospheric measurement record and in ice core records dating back as far as 800000 years. One of the strongest El Nino events since at least 1950 dissipated in spring, and a weak La Nina evolved later in the year. Owing at least in part to the combination of El Nino conditions early in the year and a long-term upward trend, Earth's surface observed record warmth for a third consecutive year, albeit by a much slimmer margin than by which that record was set in 2015. Above Earth's surface, the annual lower troposphere temperature was record high according to all datasets analyzed, while the lower stratospheric temperature was record low according to most of the in situ and satellite datasets. Several countries, including Mexico and India, reported record high annual temperatures while many others observed near-record highs. A week-long heat wave at the end of April over the northern and eastern Indian peninsula, with temperatures surpassing 44 degrees C, contributed to a water crisis for 330 million people and to 300 fatalities. In the Arctic the 2016 land surface temperature was 2.0 degrees C above the 1981-2010 average, breaking the previous record of 2007, 2011, and 2015 by 0.8 degrees C, representing a 3.5 degrees C increase since the record began in 1900. The increasing temperatures have led to decreasing Arctic sea ice extent and thickness. On 24 March, the sea ice extent at the end of the growth season saw its lowest maximum in the 37-year satellite record, tying with 2015 at 7.2% below the 1981-2010 average. The September 2016 Arctic sea ice minimum extent tied with 2007 for the second lowest value on record, 33% lower than the 1981-2010 average. Arctic sea ice cover remains relatively young and thin, making it vulnerable to continued extensive melt. The mass of the Greenland Ice Sheet, which has the capacity to contribute similar to 7 m to sea level rise, reached a record low value. The onset of its surface melt was the second earliest, after 2012, in the 37-year satellite record. Sea surface temperature was record high at the global scale, surpassing the previous record of 2015 by about 0.01 degrees C. The global sea surface temperature trend for the 21st century-to-date of +0.162 degrees C decade(-1) is much higher than the longer term 1950-2016 trend of +0.100 degrees C decade(-1). Global annual mean sea level also reached a new record high, marking the sixth consecutive year of increase. Global annual ocean heat content saw a slight drop compared to the record high in 2015. Alpine glacier retreat continued around the globe, and preliminary data indicate that 2016 is the 37th consecutive year of negative annual mass balance. Across the Northern Hemisphere, snow cover for each month from February to June was among its four least extensive in the 47-year satellite record. Continuing a pattern below the surface, record high temperatures at 20-m depth were measured at all permafrost observatories on the North Slope of Alaska and at the Canadian observatory on northernmost Ellesmere Island. In the Antarctic, record low monthly surface pressures were broken at many stations, with the southern annular mode setting record high index values in March and June. Monthly high surface pressure records for August and November were set at several stations. During this period, record low daily and monthly sea ice extents were observed, with the November mean sea ice extent more than 5 standard deviations below the 1981-2010 average. These record low sea ice values contrast sharply with the record high values observed during 2012-14. Over the region, springtime Antarctic stratospheric ozone depletion was less severe relative to the 1991-2006 average, but ozone levels were still low compared to pre-1990 levels. Closer to the equator, 93 named tropical storms were observed during 2016, above the 1981-2010 average of 82, but fewer than the 101 storms recorded in 2015. Three basins-the North Atlantic, and eastern and western North Pacific-experienced above-normal activity in 2016. The Australian basin recorded its least active season since the beginning of the satellite era in 1970. Overall, four tropical cyclones reached the Saffir-Simpson category 5 intensity level. The strong El Nino at the beginning of the year that transitioned to a weak La Nina contributed to enhanced precipitation variability around the world. Wet conditions were observed throughout the year across southern South America, causing repeated heavy flooding in Argentina, Paraguay, and Uruguay. Wetter-than-usual conditions were also observed for eastern Europe and central Asia, alleviating the drought conditions of 2014 and 2015 in southern Russia. In the United States, California had its first wetter-than-average year since 2012, after being plagued by drought for several years. Even so, the area covered by drought in 2016 at the global scale was among the largest in the post-1950 record. For each month, at least 12% of land surfaces experienced severe drought conditions or worse, the longest such stretch in the record. In northeastern Brazil, drought conditions were observed for the fifth consecutive year, making this the longest drought on record in the region. Dry conditions were also observed in western Bolivia and Peru; it was Bolivia's worst drought in the past 25 years. In May, with abnormally warm and dry conditions already prevailing over western Canada for about a year, the human-induced Fort McMurray wildfire burned nearly 590000 hectares and became the costliest disaster in Canadian history, with $3 billion (U.S. dollars) in insured losses.
Published: 2017
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14. Global and regional emissions estimates for N2O

Author: Saikawa, E., Prinn, R. G., Dlugokencky, E., Ishijima, K., Dutton, G. S., Hall, B. D., Langenfelds, R., Tohjima, Y., Machida, T., Manizza, M., Rigby, M., O'Doherty, S., Patra, P. K., Harth, C. M., Weiss, R. F., Krummel, P. B., van der Schoot, M., Fraser, P. J., Steele, L. P., Aoki, S., Nakazawa, T., and Elkins, J. W.
Subjects: SURFACE DATA, NITRIC-OXIDE, lcsh:QC1-999, AGGREGATION ERRORS, lcsh:Chemistry, CARBON-DIOXIDE, lcsh:QD1-999, CHEMICAL-TRANSPORT MODELS, INVERSION, GENERAL-CIRCULATION MODEL, ATMOSPHERIC NITROUS-OXIDE, TRACE GAS EMISSIONS, lcsh:Physics, GREENHOUSE GASES
Abstract: We present a comprehensive estimate of nitrous oxide (N2O) emissions using observations and models from 1995 to 2008. High-frequency records of tropospheric N2O are available from measurements at Cape Grim, Tasmania; Cape Matatula, American Samoa; Ragged Point, Barbados; Mace Head, Ireland; and at Trinidad Head, California using the Advanced Global Atmospheric Gases Experiment (AGAGE) instrumentation and calibrations. The Global Monitoring Division of the National Oceanic and Atmospheric Administration/Earth System Research Laboratory (NOAA/ESRL) has also collected discrete air samples in flasks and in situ measurements from remote sites across the globe and analyzed them for a suite of species including N2O. In addition to these major networks, we include in situ and aircraft measurements from the National Institute of Environmental Studies (NIES) and flask measurements from the Tohoku University and Commonwealth Scientific and Industrial Research Organization (CSIRO) networks. All measurements show increasing atmospheric mole fractions of N2O, with a varying growth rate of 0.1–0.7% per year, resulting in a 7.4% increase in the background atmospheric mole fraction between 1979 and 2011. Using existing emission inventories as well as bottom-up process modeling results, we first create globally gridded a priori N2O emissions over the 37 years since 1975. We then use the three-dimensional chemical transport model, Model for Ozone and Related Chemical Tracers version 4 (MOZART v4), and a Bayesian inverse method to estimate global as well as regional annual emissions for five source sectors from 13 regions in the world. This is the first time that all of these measurements from multiple networks have been combined to determine emissions. Our inversion indicates that global and regional N2O emissions have an increasing trend between 1995 and 2008. Despite large uncertainties, a significant increase is seen from the Asian agricultural sector in recent years, most likely due to an increase in the use of nitrogenous fertilizers, as has been suggested by previous studies.
Published: 2014
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15. Transport mechanisms for synoptic, seasonal and interannual SF6 variations and 'age' of air in troposphere

Author: Patra, P. K., Takigawa, M., Dutton, G. S., Uhse, K., Ishijima, K., Lintner, B. R., Kazuyuki Miyazaki, and Elkins, J. W.
Subjects: lcsh:Chemistry, lcsh:QD1-999, lcsh:Physics, lcsh:QC1-999
Abstract: We use an atmospheric general circulation model (AGCM) driven chemistry-transport model (ACTM) to simulate the evolution of sulfur hexafluoride (SF6) in the troposphere. The model results are compared with continuous measurements at 6 sites over 71° N–90° S. These comparisons demonstrate that the ACTM simulations lie within the measurement uncertainty over the analysis period (1999–2006) and capture salient features of synoptic, seasonal and interannual SF6 variability. To understand transport timescales of SF6 within the troposphere, transport times of air parcels from the surface to different regions of the troposphere ("age") are estimated from a simulation of an idealized tracer. The age estimation error and its sensitivity to the selection of reanalysis meteorology for ACTM nudging or the tracer transport by deep cumulus convection as represented in the model are discussed. Monthly-mean, 2-box model exchange times (τex) are calculated from both the observed and simulated SF6 time series at the 6 observing sites and show favorable agreement, suggesting that the ACTM adequately represents large-scale interhemispheric transport. The simulated SF6 variability is further investigated through decomposition of the mixing ratio time-tendency into advective, convective, and vertical diffusive components. The transport component analysis illustrates the role of each process in SF6 synoptic variability at the site level and provides insight into the seasonality of τex.
Published: 2009

16. Simulation of atmospheric N[subscript 2]O with GEOS-Chem and its adjoint: evaluation of observational constraints

Author: Wells, K. C., Millet, D. B., Bousserez, N., Henze, D. K., Chaliyakunnel, S., Griffis, T. J., Luan, Y., Dlugokencky, E. J., O'Doherty, Simon, Weiss, R. F., Dutton, G. S., Elkins, J. W., Krummel, P. B., Langenfelds, R. L., Steele, L. P., Kort, E. A., Wofsy, S. C., Umezawa, T., Prinn, Ronald G., Massachusetts Institute of Technology. Center for Global Change Science, and Prinn, Ronald G.
Abstract: We describe a new 4D-Var inversion framework for nitrous oxide (N[subscript 2]O) based on the GEOS-Chem chemical transport model and its adjoint, and apply it in a series of observing system simulation experiments to assess how well N[subscript 2]O sources and sinks can be constrained by the current global observing network. The employed measurement ensemble includes approximately weekly and quasi-continuous N[subscript 2]O measurements (hourly averages used) from several long-term monitoring networks, N[subscript 2]O measurements collected from discrete air samples onboard a commercial aircraft (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container; CARIBIC), and quasi-continuous measurements from the airborne HIAPER Pole-to-Pole Observations (HIPPO) campaigns. For a 2-year inversion, we find that the surface and HIPPO observations can accurately resolve a uniform bias in emissions during the first year; CARIBIC data provide a somewhat weaker constraint. Variable emission errors are much more difficult to resolve given the long lifetime of N[subscript 2]O, and major parts of the world lack significant constraints on the seasonal cycle of fluxes. Current observations can largely correct a global bias in the stratospheric sink of N[subscript 2]O if emissions are known, but do not provide information on the temporal and spatial distribution of the sink. However, for the more realistic scenario where source and sink are both uncertain, we find that simultaneously optimizing both would require unrealistically small errors in model transport. Regardless, a bias in the magnitude of the N[subscript 2]O sink would not affect the a posteriori N[subscript 2]O emissions for the 2-year timescale used here, given realistic initial conditions, due to the timescale required for stratosphere–troposphere exchange (STE). The same does not apply to model errors in the rate of STE itself, which we show exerts a larger influence on the tropospheric burden of N[subscript 2]O than does the chemical loss rate over short (< 3 year) timescales. We use a stochastic estimate of the inverse Hessian for the inversion to evaluate the spatial resolution of emission constraints provided by the observations, and find that significant, spatially explicit constraints can be achieved in locations near and immediately upwind of surface measurements and the HIPPO flight tracks; however, these are mostly confined to North America, Europe, and Australia. None of the current observing networks are able to provide significant spatial information on tropical N[subscript 2]O emissions. There, averaging kernels (describing the sensitivity of the inversion to emissions in each grid square) are highly smeared spatially and extend even to the midlatitudes, so that tropical emissions risk being conflated with those elsewhere. For global inversions, therefore, the current lack of constraints on the tropics also places an important limit on our ability to understand extratropical emissions. Based on the error reduction statistics from the inverse Hessian, we characterize the atmospheric distribution of unconstrained N[subscript 2]O, and identify regions in and downwind of South America, central Africa, and Southeast Asia where new surface or profile measurements would have the most value for reducing present uncertainty in the global N[subscript 2]O budget., United States. National Oceanic and Atmospheric Administration (Grant NA13OAR4310086), Minnesota Supercomputing Institute
Published: 2015

17. MIPAS IMK/IAA CFC-11 (CCl₃F) and CFC-12 (CCl₂F₂) measurements: accuracy, precision and long-term stability

Author: Eckert, E., Laeng, A., Lossow, S., Kellmann, S., Stiller, G., Von Clarmann, T., Glatthor, N., Höpfner, M., Kiefer, M., Oelhaf, H., Orphal, J., Funke, B., Grabowski, U., Haenel, F., Linden, A., Wetzel, G., Woiwode, W., Bernath, P. F., Boone, C., Dutton, G. S., Elkins, J. W., Engel, A., Gille, J. C., Kolonjari, F., Sugita, T., Toon, G. C., and Walker, K. A.
Subjects: Earth sciences, ddc:550
Abstract: Profiles of CFC-11 (CCl$_{3}$F) and CFC-12 (CCl$_{2}$F$_{2}$) of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) aboard the European satellite Envisat have been retrieved from versions MIPAS/4.61 to MIPAS/ 4.62 and MIPAS/5.02 to MIPAS/5.06 level-1b data using the scientific level-2 processor run by Karlsruhe Institute of Technology (KIT), Institute of Meteorology and Climate Research (IMK) and Consejo Superior de Investigaciones Científicas (CSIC), Instituto de Astrofísica de Andalucía (IAA). These profiles have been compared to measurements taken by the balloon-borne cryosampler, Mark IV (MkIV) and MIPAS-Balloon (MIPAS-B), the airborne MIPAS-STRatospheric aircraft (MIPAS-STR), the satellite-borne Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) and the High Resolution Dynamic Limb Sounder (HIRDLS), as well as the groundbased Halocarbon and other Atmospheric Trace Species (HATS) network for the reduced spectral resolution period (RR: January 2005–April 2012) of MIPAS. ACE-FTS, MkIV and HATS also provide measurements during the high spectral resolution period (full resolution, FR: July 2002–March 2004) and were used to validate MIPAS CFC-11 and CFC- 12 products during that time, as well as profiles from the Improved Limb Atmospheric Spectrometer, ILAS-II. In general, we find that MIPAS shows slightly higher values for CFC-11 at the lower end of the profiles (below 15 km) and in a comparison of HATS ground-based data and MIPAS measurements at 3 km below the tropopause. Differences range from approximately 10 to 50 pptv ( ~5–20 %) during the RR period. In general, differences are slightly smaller for the FR period. An indication of a slight high bias at the lower end of the profile exists for CFC-12 as well, but this bias is far less pronounced than for CFC-11 and is not as obvious in the relative differences between MIPAS and any of the comparison instruments. Differences at the lower end of the profile (below ~15 km) and in the comparison of HATS and MIPAS measurements taken at 3 km below the tropopause mainly stay within 10–50 pptv (corresponding to ~ 2–10% for CFC-12) for the RR and the FR period. Between ~15 and 30 km, most comparisons agree within 10–20 pptv (10–20 %), apart from ILAS-II, which shows large differences above ~17 km. Overall, relative differences are usually smaller for CFC-12 than for CFC-11. For both species – CFC-11 and CFC-12 – we find that differences at the lower end of the profile tend to be larger at higher latitudes than in tropical and subtropical regions. In addition, MIPAS profiles have a maximum in their mixing ratio around the tropopause, which is most obvious in tropical mean profiles. Comparisons of the standard deviation in a quiescent atmosphere (polar summer) show that only the CFC-12 FR error budget can fully explain the observed variability, while for the other products (CFC-11 FR and RR and CFC-12 RR) only two-thirds to three-quarters can be explained. Investigations regarding the temporal stability show very small negative drifts in MIPAS CFC-11 measurements. These instrument drifts vary between ~1 and 3% decade$^{-1}$. For CFC-12, the drifts are also negative and close to zero up to ~30 km. Above that altitude, larger drifts of up to 50% decade$^{-1}$ appear which are negative up to ~35 km and positive, but of a similar magnitude, above.
Published: 2015

18. Global and regional emissions estimates for N[subscript 2]O

Author: Dlugokencky, E., Ishijima, K., Dutton, G. S., Hall, B. D., Langenfelds, R. L., Tohjima, Y., Machida, Toshinobu, Manizza, Manfredi, Rigby, M., O'Doherty, Simon, Patra, P. K., Harth, C. M., Weiss, R. F., Krummel, P. B., van der Schoot, M., Fraser, P. J., Steele, L. P., Aoki, S., Nakazawa, T., Elkins, J. W., Saikawa, Eri, Prinn, Ronald G., Massachusetts Institute of Technology. Center for Global Change Science, Saikawa, Eri, and Prinn, Ronald G.
Abstract: We present a comprehensive estimate of nitrous oxide (N[subscript 2]O) emissions using observations and models from 1995 to 2008. High-frequency records of tropospheric N[subscript 2]O are available from measurements at Cape Grim, Tasmania; Cape Matatula, American Samoa; Ragged Point, Barbados; Mace Head, Ireland; and at Trinidad Head, California using the Advanced Global Atmospheric Gases Experiment (AGAGE) instrumentation and calibrations. The Global Monitoring Division of the National Oceanic and Atmospheric Administration/Earth System Research Laboratory (NOAA/ESRL) has also collected discrete air samples in flasks and in situ measurements from remote sites across the globe and analyzed them for a suite of species including N[subscript 2]O. In addition to these major networks, we include in situ and aircraft measurements from the National Institute of Environmental Studies (NIES) and flask measurements from the Tohoku University and Commonwealth Scientific and Industrial Research Organization (CSIRO) networks. All measurements show increasing atmospheric mole fractions of N[subscript 2]O, with a varying growth rate of 0.1–0.7% per year, resulting in a 7.4% increase in the background atmospheric mole fraction between 1979 and 2011. Using existing emission inventories as well as bottom-up process modeling results, we first create globally gridded a priori N[subscript 2]O emissions over the 37 years since 1975. We then use the three-dimensional chemical transport model, Model for Ozone and Related Chemical Tracers version 4 (MOZART v4), and a Bayesian inverse method to estimate global as well as regional annual emissions for five source sectors from 13 regions in the world. This is the first time that all of these measurements from multiple networks have been combined to determine emissions. Our inversion indicates that global and regional N[subscript 2]O emissions have an increasing trend between 1995 and 2008. Despite large uncertainties, a significant increase is seen from the Asian agricultural sector in recent years, most likely due to an increase in the use of nitrogenous fertilizers, as has been suggested by previous studies., NASA Upper Atmospheric Research Program (Grant NNX11AF17G), NASA Upper Atmospheric Research Program (Grant NNX07AF09G), NASA Upper Atmospheric Research Program (Grant NNX07AE87G), United States. National Oceanic and Atmospheric Administration (Contract RA133R09CN0062)
Published: 2014

19. MIPAS IMK/IAA CFC-11 (CCl3F) and CFC-12 (CCl2F2) measurements: accuracy, precision and long-term stability

Author: Eckert, E., primary, Laeng, A., additional, Lossow, S., additional, Kellmann, S., additional, Stiller, G., additional, von Clarmann, T., additional, Glatthor, N., additional, Höpfner, M., additional, Kiefer, M., additional, Oelhaf, H., additional, Orphal, J., additional, Funke, B., additional, Grabowski, U., additional, Haenel, F., additional, Linden, A., additional, Wetzel, G., additional, Woiwode, W., additional, Bernath, P. F., additional, Boone, C., additional, Dutton, G. S., additional, Elkins, J. W., additional, Engel, A., additional, Gille, J. C., additional, Kolonjari, F., additional, Sugita, T., additional, Toon, G. C., additional, and Walker, K. A., additional
Published: 2016
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20. Simulation of atmospheric N[subscript 2]O with GEOS-Chem and its adjoint: evaluation of observational constraints

Author: Massachusetts Institute of Technology. Center for Global Change Science, Prinn, Ronald G., Wells, K. C., Millet, D. B., Bousserez, N., Henze, D. K., Chaliyakunnel, S., Griffis, T. J., Luan, Y., Dlugokencky, E. J., O'Doherty, Simon, Weiss, R. F., Dutton, G. S., Elkins, J. W., Krummel, P. B., Langenfelds, R. L., Steele, L. P., Kort, E. A., Wofsy, S. C., Umezawa, T., Massachusetts Institute of Technology. Center for Global Change Science, Prinn, Ronald G., Wells, K. C., Millet, D. B., Bousserez, N., Henze, D. K., Chaliyakunnel, S., Griffis, T. J., Luan, Y., Dlugokencky, E. J., O'Doherty, Simon, Weiss, R. F., Dutton, G. S., Elkins, J. W., Krummel, P. B., Langenfelds, R. L., Steele, L. P., Kort, E. A., Wofsy, S. C., and Umezawa, T.
Abstract: We describe a new 4D-Var inversion framework for nitrous oxide (N[subscript 2]O) based on the GEOS-Chem chemical transport model and its adjoint, and apply it in a series of observing system simulation experiments to assess how well N[subscript 2]O sources and sinks can be constrained by the current global observing network. The employed measurement ensemble includes approximately weekly and quasi-continuous N[subscript 2]O measurements (hourly averages used) from several long-term monitoring networks, N[subscript 2]O measurements collected from discrete air samples onboard a commercial aircraft (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container; CARIBIC), and quasi-continuous measurements from the airborne HIAPER Pole-to-Pole Observations (HIPPO) campaigns. For a 2-year inversion, we find that the surface and HIPPO observations can accurately resolve a uniform bias in emissions during the first year; CARIBIC data provide a somewhat weaker constraint. Variable emission errors are much more difficult to resolve given the long lifetime of N[subscript 2]O, and major parts of the world lack significant constraints on the seasonal cycle of fluxes. Current observations can largely correct a global bias in the stratospheric sink of N[subscript 2]O if emissions are known, but do not provide information on the temporal and spatial distribution of the sink. However, for the more realistic scenario where source and sink are both uncertain, we find that simultaneously optimizing both would require unrealistically small errors in model transport. Regardless, a bias in the magnitude of the N[subscript 2]O sink would not affect the a posteriori N[subscript 2]O emissions for the 2-year timescale used here, given realistic initial conditions, due to the timescale required for stratosphere–troposphere exchange (STE). The same does not apply to model errors in the rate of STE itself, which we show exerts a larger influence on the troposphe, United States. National Oceanic and Atmospheric Administration (Grant NA13OAR4310086), Minnesota Supercomputing Institute
Published: 2015

21. Re-evaluation of the lifetimes of the major CFCs and CH[subscript 3]CCl[subscript 3] using atmospheric trends

Author: O'Doherty, Simon, Montzka, Stephen A., McCulloch, A., Harth, C. M., Muhle, Jens, Salameh, P. K., Weiss, R. F., Young, D., Simmonds, P. G., Hall, B. D., Dutton, G. S., Nance, D., Mondeel, D. J., Elkins, J. W., Krummel, P. B., Steele, L. P., Fraser, P. J., Rigby, Matthew, Prinn, Ronald G., Massachusetts Institute of Technology. Center for Global Change Science, Rigby, Matthew, and Prinn, Ronald G.
Abstract: Since the Montreal Protocol on Substances that Deplete the Ozone Layer and its amendments came into effect, growth rates of the major ozone depleting substances (ODS), particularly CFC-11, -12 and -113 and CH[subscript 3]CCl[subscript 3], have declined markedly, paving the way for global stratospheric ozone recovery. Emissions have now fallen to relatively low levels, therefore the rate at which this recovery occurs will depend largely on the atmospheric lifetime of these compounds. The first ODS measurements began in the early 1970s along with the first lifetime estimates calculated by considering their atmospheric trends. We now have global mole fraction records spanning multiple decades, prompting this lifetime re-evaluation. Using surface measurements from the Advanced Global Atmospheric Gases Experiment (AGAGE) and the National Oceanic and Atmospheric Administration Global Monitoring Division (NOAA GMD) from 1978 to 2011, we estimated the lifetime of CFC-11, CFC-12, CFC-113 and CH[subscript 3]CCl[subscript 3] using a multi-species inverse method. A steady-state lifetime of 45 yr for CFC-11, currently recommended in the most recent World Meteorological Organisation (WMO) Scientific Assessments of Ozone Depletion, lies towards the lower uncertainty bound of our estimates, which are 54[61 over 48] yr (1-sigma uncertainty) when AGAGE data were used and 52[61 over 45] yr when the NOAA network data were used. Our derived lifetime for CFC-113 is significantly higher than the WMO estimates of 85 yr, being 109[121 over 99] (AGAGE) and 109[124 over 97] (NOAA). New estimates of the steady-state lifetimes of CFC-12 and CH[subscript 3]CCl[subscript 3] are consistent with the current WMO recommendations, being 111[132 over 95] and 112[136 over 95] yr (CFC-12, AGAGE and NOAA respectively) and 5.04[5.20 over 4.92] and 5.04[5.23 over 4.87] yr (CH[subscript 3]CCl[subscript 3], AGAGE and NOAA respectively)., NASA Upper Atmospheric Research Program (Advanced Global Atmospheric Gases Experiment (AGAGE) Grant NNX07AE89G), NASA Upper Atmospheric Research Program (Advanced Global Atmospheric Gases Experiment (AGAGE) Grant NNX11AF17G)
Published: 2013

22. Global CFC-11 (CFCl3) and CFC-12 (CF2Cl2) measurements with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS): retrieval, climatologies and trends

Author: Kellmann, S., Clarmann, T. von, Stiller, G. P., Eckert, E., Glatthor, N., Höpfner, M., Kiefer, M., Orphal, J., Funke, B., Grabowski, U., Linden, A., Dutton, G. S., and Elkins, J. W.
Subjects: Earth sciences, ddc:550
Published: 2012
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23. STATE OF THE CLIMATE IN 2011 Special Supplement to the Bulletin of the American Meteorological Society Vol. 93, No. 7, July 2012

Author: Arndt, D. S., Blunden, J., Willett, K. M., Dolman, A. J., Hall, B. D., Thorne, P. W., Gregg, M. C., Newlin, M. L., Xue, Y., Hu, Z., Kumar, A., Banzon, V., Smith, T. M., Rayner, N. A., Jeffries, M. O., Richter-Menge, J., Overland, J., Bhatt, U., Key, J., Liu, Y., Walsh, J., Wang, M., Fogt, R. L., Scambos, T. A., Wovrosh, A. J., Barreira, S., Sanchez-Lugo, A., Renwick, J. A., Thiaw, W. M., Weaver, S. J., Whitewood, R., Phillips, D., Achberger, C., Ackerman, S. A., Ahmed, F. H., Albanil-Encarnacion, A., Alfaro, E. J., Alves, L. M., Allan, R., Amador, J. A., Ambenje, P., Antoine, M. D., Antonov, J., Arevalo, J., Ashik, I., Atheru, Z., Baccini, A., Baez, J., Baringer, M. O., Barriopedro, D. E., Bates, J. J., Becker, A., Behrenfeld, M. J., Bell, G. D., Benedetti, A., Bernhard, G., Berrisford, P., Berry, D. I., Beszczynska-Moeller, A., Bhatt, U. S., Bidegain, M., Bieniek, P., Birkett, C., Bissolli, P., Blake, E. S., Boudet-Rouco, D., Box, J. E., Boyer, T., Braathen, G. O., Brackenridge, G. R., Brohan, P., Bromwich, D. H., Brown, L., Brown, R., Bruhwiler, L., Bulygina, O. N., Burrows, J., Calderon, B., Camargo, S. J., Cappellen, J., Carmack, E., Carrasco, G., Chambers, D. P., Christiansen, H. H., Christy, J., Chung, D., Ciais, P., Coehlo, C. A. S., Colwell, S., Comiso, J., Cretaux, J. F., Crouch, J., Cunningham, S. A., Jeu, R. A. M., Demircan, M., Derksen, C., Diamond, H. J., Dlugokencky, E. J., Dohan, K., Dorigo, W. A., Drozdov, D. S., Duguay, C., Dutton, E., Dutton, G. S., Elkins, J. W., Epstein, H. E., Famiglietti, J. S., Fanton D Andon, O. H., Feely, R. A., Fekete, B. M., Fenimore, C., Fernandez-Prieto, D., Fields, E., Fioletov, V., Folland, C., Foster, M. J., Frajka-Williams, E., Franz, B. A., Frey, K., Frith, S. H., Frolov, I., Frost, G. V., Ganter, C., Garzoli, S., Gitau, W., Gleason, K. L., Gobron, N., Goldenberg, S. B., Goni, G., Gonzalez-Garcia, I., Gonzalez-Rodriguez, N., Good, S. A., Goryl, P., Gottschalck, J., Gouveia, C. M., Griffiths, G. M., Grigoryan, V., Grooss, J. U., Guard, C., Guglielmin, M., Halpert, M. S., Heidinger, A. K., Heikkila, A., Heim, R. R., Hennon, P. A., Hidalgo, H. G., Hilburn, K., Ho, S. P., Hobbs, W. R., Holgate, S., Hook, S. J., Hovsepyan, A., Hu, Z. Z., Hugony, S., Hurst, D. F., Ingvaldsen, R., Itoh, M., Jaimes, E., Jeffries, M., Johns, W. E., Johnsen, B., Johnson, B., Johnson, G. C., Jones, L. T., Jumaux, G., Kabidi, K., Kaiser, J. W., Kang, K. K., Kanzow, T. O., Kao, H. Y., Keller, L. M., Kendon, M., Kennedy, J. J., Kervankiran, S., Khatiwala, S., Kholodov, A. L., Khoshkam, M., Kikuchi, T., Kimberlain, T. B., King, D., Knaff, J. A., Korshunova, N. N., Koskela, T., Kratz, D. P., Krishfield, R., Kruger, A., Kruk, M. C., Lagerloef, G., Lakkala, K., Lammers, R. B., Lander, M. A., Landsea, C. W., Lankhorst, M., Lapinel-Pedroso, B., Lazzara, M. A., Leduc, S., Lefale, P., Leon, G., Leon-Lee, A., Leuliette, E., Levitus, S., L Heureux, M., Lin, II, Liu, H. X., Liu, Y. J., Lobato-Sanchez, R., Locarnini, R., Loeb, N. G., Loeng, H., Long, C. S., Lorrey, A. M., Lumpkin, R., Myhre, C. L., Jing-Jia Luo, Lyman, J. M., Maccallum, S., Macdonald, A. M., Maddux, B. C., Manney, G., Marchenko, S. S., Marengo, J. A., Maritorena, S., Marotzke, J., Marra, J. J., Martinez-Sanchez, O., Maslanik, J., Massom, R. A., Mathis, J. T., Mcbride, C., Mcclain, C. R., Mcgrath, D., Mcgree, S., Mclaughlin, F., Mcvicar, T. R., Mears, C., Meier, W., Meinen, C. S., Menendez, M., Merchant, C., Merrifield, M. A., Miller, L., Mitchum, G. T., Montzka, S. A., Moore, S., Mora, N. P., Morcrette, J. J., Mote, T., Muhle, J., Mullan, A. B., Muller, R., Myhre, C., Nash, E. R., Nerem, R. S., Newman, P. A., Ngari, A., Nishino, S., Njau, L. N., Noetzli, J., Oberman, N. G., Obregon, A., Ogallo, L., Oludhe, C., Oyunjargal, L., Parinussa, R. M., Park, G. H., Parker, D. E., Pasch, R. J., Pascual-Ramirez, R., Pelto, M. S., Penalba, O., Perez-Suarez, R., Perovich, D., Pezza, A. B., Pickart, R., Pinty, B., Pinzon, J., Pitts, M. C., Pour, H. K., Prior, J., Privette, J. L., Proshutinsky, A., Quegan, S., Quintana, J., Rabe, B., Rahimzadeh, F., Rajeevan, M., Rayner, D., Raynolds, M. K., Razuvaev, V. N., Reagan, J., Reid, P., Revadekar, J., Rex, M., Rivera, I. L., Robinson, D. A., Rodell, M., Roderick, M. L., Romanovsky, V. E., Ronchail, J., Rosenlof, K. H., Rudels, B., Sabine, C. L., Santee, M. L., Sawaengphokhai, P., Sayouri, A., Schauer, U., Schemm, J., Schmid, C., Schreck, C., Semiletov, I., Send, U., Sensoy, S., Shakhova, N., Sharp, M., Shiklomanov, N. I., Shimada, K., Shin, J., Siegel, D. A., Simmons, A., Skansi, M., Sokolov, V., Spence, J., Srivastava, A. K., Stackhouse, P. W., Stammerjohn, S., Steele, M., Steffen, K., Steinbrecht, W., Stephenson, T., Stolarski, R. S., Sweet, W., Takahashi, T., Taylor, M. A., Tedesco, M., Thepaut, J. N., Thompson, P., Timmermans, M. L., Tobin, S., Toole, J., Trachte, K., Trewin, B. C., Trigo, R. M., Trotman, A., Tucker, C. J., Ulupinar, Y., Wal, R. S. W., Werf, G. R., Vautard, R., Votaw, G., Wagner, W. W., Wahr, J., Walker, D. A., Wang, C. Z., Wang, J. H., Wang, L., Wang, M. H., Wang, S. H., Wanninkhof, R., Weaver, S., Weber, M., Weingartner, T., Weller, R. A., Wentz, F., Wilber, A. C., Williams, W., Willis, J. K., Wilson, R. C., Wolken, G., Wong, T. M., Woodgate, R., Yamada, R., Yamamoto-Kawai, M., Yoder, J. A., Yu, L. S., Yueh, S., Zhang, L. Y., Zhang, P. Q., Zhao, L., Zhou, X. J., Zimmermann, S., Zubair, L., Laboratoire d'études en Géophysique et océanographie spatiales (LEGOS), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), National Oceanic and Atmospheric Administration (NOAA), Lamont-Doherty Earth Observatory (LDEO), Columbia University [New York], Space Technology Center, European Centre for Medium-Range Weather Forecasts (ECMWF), Climate Research Division [Toronto], Environment and Climate Change Canada, Earth and Space Research Institute [Seattle] (ESR), Department of Hydrology and Geo-Environmental Sciences [Amsterdam], Vrije Universiteit Amsterdam [Amsterdam] (VU), Vienna University of Technology (TU Wien), Instituto Dom Luiz, Universidade de Lisboa = University of Lisbon (ULISBOA), NOAA Earth System Research Laboratory (ESRL), Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado [Boulder]-National Oceanic and Atmospheric Administration (NOAA), Department of Earth System Science [Irvine] (ESS), University of California [Irvine] (UC Irvine), University of California (UC)-University of California (UC), Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), University of California Center for Hydrologic Modeling [Irvine] (UCCHM), NOAA Pacific Marine Environmental Laboratory [Seattle] (PMEL), Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - 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University of Applied Sciences, Laboratoire d'océanographie de Villefranche (LOV), Observatoire océanologique de Villefranche-sur-mer (OOVM), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), Indian Institute of Tropical Meteorology (IITM), Ministry of Earth Sciences [India], Woods Hole Research Center, Department of Earth and Environment [Boston], Boston University [Boston] (BU), Centre for Australian Weather and Climate Research (CAWCR), Alfred-Wegener-Institut, Helmholtz-Zentrum für Polar- und Meeresforschung (AWI), Génétique et Ecologie des Virus, Génétique des Virus et Pathogénèse des Maladies Virales, Université Paris Diderot - Paris 7 (UPD7)-Institut National de la Santé et de la Recherche Médicale (INSERM), Department of Botany and Plant Pathology, Oregon State University (OSU), Ctr Ecol & Hydrol, Bangor, Environm Ctr Wales, Biospherical Instruments Inc., Processus de la variabilité climatique tropicale et impacts (PARVATI), Laboratoire d'Océanographie et du Climat : Expérimentations et Approches Numériques (LOCEAN), Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS-PSL), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Muséum national d'Histoire naturelle (MNHN)-Institut de Recherche pour le Développement (IRD)-Université Pierre et Marie Curie - 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[Hampton] (SSAI), National Snow and Ice Data Center (NSIDC), Naval Postgraduate School (NPS), University of California [Berkeley] (UC Berkeley), Centre de physique moléculaire optique et hertzienne (CPMOH), Université Sciences et Technologies - Bordeaux 1 (UB)-Centre National de la Recherche Scientifique (CNRS), CYRIC, Tohoku University [Sendai], The University of Tennessee [Knoxville], Oak Ridge National Laboratory [Oak Ridge] (ORNL), UT-Battelle, LLC, The University Centre in Svalbard (UNIS), Institute of Arctic Alpine Research [University of Colorado Boulder] (INSTAAR), Swiss Federal Institute for Forest, Snow and Landscape Research WSL, Meteorologisches Observatorium Hohenpeißenberg (MOHp), Deutscher Wetterdienst [Offenbach] (DWD), British Antarctic Survey (BAS), Natural Environment Research Council (NERC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Météo France-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS), Universidade de Lisboa (ULISBOA), University of California [Irvine] (UCI), University of California-University of California, Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Universitá degli Studi dell’Insubria, University of Costa Rica, Météo France [Sainte-Clotilde], Météo France, University of Oxford [Oxford], Scripps Institution of Oceanography (SIO), Huazhong Agricultural University, University of California, NMR and Molecular Imaging Laboratory [Mons], University of Mons [Belgium] (UMONS), Lausanne University Hospital [Switzerland], Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de la Mer de Villefranche (IMEV), Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris Diderot - Paris 7 (UPD7), Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-École normale supérieure - Paris (ENS Paris), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris Diderot - Paris 7 (UPD7)-École polytechnique (X)-Centre National d'Études Spatiales [Toulouse] (CNES)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche pour le Développement (IRD)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Muséum national d'Histoire naturelle (MNHN)-Institut Pierre-Simon-Laplace (IPSL (FR_636)), Berkeley University of California (UC BERKELEY), Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1, and Institute of Arctic and Alpine Research (INSTAAR)
Subjects: [SDU.STU.OC]Sciences of the Universe [physics]/Earth Sciences/Oceanography
Abstract: International audience; Large-scale climate patterns influenced temperature and weather patterns around the globe in 2011. In particular, a moderate-to-strong La Nina at the beginning of the year dissipated during boreal spring but reemerged during fall. The phenomenon contributed to historical droughts in East Africa, the southern United States, and northern Mexico, as well the wettest two-year period (2010-11) on record for Australia, particularly remarkable as this follows a decade-long dry period. Precipitation patterns in South America were also influenced by La Nina. Heavy rain in Rio de Janeiro in January triggered the country's worst floods and landslides in Brazil's history. The 2011 combined average temperature across global land and ocean surfaces was the coolest since 2008, but was also among the 15 warmest years on record and above the 1981-2010 average. The global sea surface temperature cooled by 0.1 degrees C from 2010 to 2011, associated with cooling influences of La Nina. Global integrals of upper ocean heat content for 2011 were higher than for all prior years, demonstrating the Earth's dominant role of the oceans in the Earth's energy budget. In the upper atmosphere, tropical stratospheric temperatures were anomalously warm, while polar temperatures were anomalously cold. This led to large springtime stratospheric ozone reductions in polar latitudes in both hemispheres. Ozone concentrations in the Arctic stratosphere during March were the lowest for that period since satellite records began in 1979. An extensive, deep, and persistent ozone hole over the Antarctic in September indicates that the recovery to pre-1980 conditions is proceeding very slowly. Atmospheric carbon dioxide concentrations increased by 2.10 ppm in 2011, and exceeded 390 ppm for the first time since instrumental records began. Other greenhouse gases also continued to rise in concentration and the combined effect now represents a 30% increase in radiative forcing over a 1990 baseline. Most ozone depleting substances continued to fall. The global net ocean carbon dioxide uptake for the 2010 transition period from El Nino to La Nina, the most recent period for which analyzed data are available, was estimated to be 1.30 Pg C yr(-1), almost 12% below the 29-year long-term average. Relative to the long-term trend, global sea level dropped noticeably in mid-2010 and reached a local minimum in 2011. The drop has been linked to the La Nina conditions that prevailed throughout much of 2010-11. Global sea level increased sharply during the second half of 2011. Global tropical cyclone activity during 2011 was well-below average, with a total of 74 storms compared with the 1981-2010 average of 89. Similar to 2010, the North Atlantic was the only basin that experienced above-normal activity. For the first year since the widespread introduction of the Dvorak intensity-estimation method in the 1980s, only three tropical cyclones reached Category 5 intensity level-all in the Northwest Pacific basin. The Arctic continued to warm at about twice the rate compared with lower latitudes. Below-normal summer snowfall, a decreasing trend in surface albedo, and above-average surface and upper air temperatures resulted in a continued pattern of extreme surface melting, and net snow and ice loss on the Greenland ice sheet. Warmer-than-normal temperatures over the Eurasian Arctic in spring resulted in a new record-low June snow cover extent and spring snow cover duration in this region. In the Canadian Arctic, the mass loss from glaciers and ice caps was the greatest since GRACE measurements began in 2002, continuing a negative trend that began in 1987. New record high temperatures occurred at 20 m below the land surface at all permafrost observatories on the North Slope of Alaska, where measurements began in the late 1970s. Arctic sea ice extent in September 2011 was the second-lowest on record, while the extent of old ice (four and five years) reached a new record minimum that was just 19% of normal. On the opposite pole, austral winter and spring temperatures were more than 3 degrees C above normal over much of the Antarctic continent. However, winter temperatures were below normal in the northern Antarctic Peninsula, which continued the downward trend there during the last 15 years. In summer, an all-time record high temperature of -12.3 degrees C was set at the South Pole station on 25 December, exceeding the previous record by more than a full degree. Antarctic sea ice extent anomalies increased steadily through much of the year, from briefly setting a record low in April, to well above average in December. The latter trend reflects the dispersive effects of low pressure on sea ice and the generally cool conditions around the Antarctic perimeter.
Published: 2012
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24. Simulation of atmospheric N2O with GEOS-Chem and its adjoint: evaluation of observational constraints

Author: Wells, K. C., primary, Millet, D. B., additional, Bousserez, N., additional, Henze, D. K., additional, Chaliyakunnel, S., additional, Griffis, T. J., additional, Luan, Y., additional, Dlugokencky, E. J., additional, Prinn, R. G., additional, O'Doherty, S., additional, Weiss, R. F., additional, Dutton, G. S., additional, Elkins, J. W., additional, Krummel, P. B., additional, Langenfelds, R., additional, Steele, L. P., additional, Kort, E. A., additional, Wofsy, S. C., additional, and Umezawa, T., additional
Published: 2015
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25. History of atmospheric SF6 [SF subscript 6] from 1973 to 2008

Author: Rigby, Matthew, Muhle, Jens, Miller, Benjamin R., Prinn, Ronald G., Krummel, P. B., Steele, L. P., Fraser, P. J., Salameh, P. K., Harth, C. M., Weiss, R. F., Greally, B. R., O'Doherty, Simon, Simmonds, P. G., Vollmer, M. K., Reimann, S., Kim, J., Kim, K.-R., Wang, H. J., Olivier, Jos G. J., Dlugokencky, E., Dutton, G. S., Hall, B. D., Elkins, J. W., Massachusetts Institute of Technology. Center for Global Change Science, Prinn, Ronald G., and Rigby, Matthew
Abstract: We present atmospheric sulfur hexafluoride (SF6)[SF subscript 6] mole fractions and emissions estimates from the 1970s to 2008. Measurements were made of archived air samples starting from 1973 in the Northern Hemisphere and from 1978 in the Southern Hemisphere, using the Advanced Global Atmospheric Gases Experiment (AGAGE) gas chromatographic-mass spectrometric (GC-MS) systems. These measurements were combined with modern high-frequency GC-MS and GC-electron capture detection (ECD) data from AGAGE monitoring sites, to produce a unique 35-year atmospheric record of this potent greenhouse gas. Atmospheric mole fractions were found to have increased by more than an order of magnitude between 1973 and 2008. The 2008 growth rate was the highest recorded, at 0.29 ± 0.02 pmolmol−1 [pmolmol superscript -1] yr−1 [yr superscript -1]. A three-dimensional chemical transport model and a minimum variance Bayesian inverse method was used to estimate annual emission rates using the measurements, with a priori estimates from the Emissions Database for Global Atmospheric Research (EDGAR, version 4). Consistent with the mole fraction growth rate maximum, global emissions during 2008 were also the highest in the 1973–2008 period, reaching 7.4 ± 0.6 Gg yr−1 [yr superscript -1] (1-σ [1 - delta] uncertainties) and surpassing the previous maximum in 1995. The 2008 values follow an increase in emissions of 48 ± 20% since 2001. A second global inversion which also incorporated National Oceanic and Atmospheric Administration (NOAA) flask measurements and in situ monitoring site data agreed well with the emissions derived using AGAGE measurements alone. By estimating continent-scale emissions using all available AGAGE and NOAA surface measurements covering the period 2004–2008, with no pollution filtering, we find that it is likely that much of the global emissions rise during this five-year period originated primarily from Asian developing countries that do not report detailed, annual emissions to the United Nations Framework Convention on Climate Change (UNFCCC). We also find it likely that SF6 [SF subscript 6] emissions reported to the UNFCCC were underestimated between at least 2004 and 2005., NASA Upper Atmospheric Research Program (Grant NNX07AE89G), NASA Upper Atmospheric Research Program (Grant NNX07AF09G), NASA Upper Atmospheric Research Program (Grant NNX07AE87G), Great Britain. Dept. for Environment, Food & Rural Affairs, United States. National Oceanic and Atmospheric Administration, Commonwealth Scientific and Industrial Research Organization (Australia), Australia. Bureau of Meteorology, Korea. Meteorological Administration. Research and Development Program (Grant CATER 2009-4109)
Published: 2010

26. MIPAS IMK/IAA CFC-11 (CCl3F) and CFC-12 (CCl2F2) measurements: accuracy, precision and long-term stability

Author: Eckert, E., primary, Laeng, A., additional, Lossow, S., additional, Kellmann, S., additional, Stiller, G., additional, von Clarmann, T., additional, Glatthor, N., additional, Höpfner, M., additional, Kiefer, M., additional, Oelhaf, H., additional, Orphal, J., additional, Funke, B., additional, Grabowski, U., additional, Haenel, F., additional, Linden, A., additional, Wetzel, G., additional, Woiwode, W., additional, Bernath, P. F., additional, Boone, C., additional, Dutton, G. S., additional, Elkins, J. W., additional, Engel, A., additional, Gille, J. C., additional, Kolonjari, F., additional, Sugita, T., additional, Toon, G. C., additional, and Walker, K. A., additional
Published: 2015
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27. Supplementary material to "Simulation of atmospheric N2O with GEOS-Chem and its adjoint: evaluation of observational constraints"

Author: Wells, K. C., primary, Millet, D. B., additional, Bousserez, N., additional, Henze, D. K., additional, Chaliyakunnel, S., additional, Griffis, T. J., additional, Luan, Y., additional, Dlugokencky, E. J., additional, Prinn, R. G., additional, O'Doherty, S., additional, Weiss, R. F., additional, Dutton, G. S., additional, Elkins, J. W., additional, Krummel, P. B., additional, Langenfelds, R., additional, Steele, L. P., additional, Kort, E. A., additional, Wofsy, S. C., additional, and Umezawa, T., additional
Published: 2015
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28. Nitrous oxide emissions 1999 to 2009 from a global atmospheric inversion

Author: Massachusetts Institute of Technology. Center for Global Change Science, Prinn, Ronald G., Thompson, R. L., Chevallier, F., Crotwell, A. M., Dutton, G. S., Langenfelds, R. L., Weiss, R. F., Tohjima, Y., Nakazawa, T., Krummel, P. B., Steele, L. P., Fraser, P. J., O'Doherty, Simon, Ishijima, K., Aoki, S., Massachusetts Institute of Technology. Center for Global Change Science, Prinn, Ronald G., Thompson, R. L., Chevallier, F., Crotwell, A. M., Dutton, G. S., Langenfelds, R. L., Weiss, R. F., Tohjima, Y., Nakazawa, T., Krummel, P. B., Steele, L. P., Fraser, P. J., O'Doherty, Simon, Ishijima, K., and Aoki, S.
Abstract: N[subscript 2]O surface fluxes were estimated for 1999 to 2009 using a time-dependent Bayesian inversion technique. Observations were drawn from 5 different networks, incorporating 59 surface sites and a number of ship-based measurement series. To avoid biases in the inverted fluxes, the data were adjusted to a common scale and scale offsets were included in the optimization problem. The fluxes were calculated at the same resolution as the transport model (3.75° longitude × 2.5° latitude) and at monthly time resolution. Over the 11-year period, the global total N[subscript 2]O source varied from 17.5 to 20.1 Tg a[superscript −1] N. Tropical and subtropical land regions were found to consistently have the highest N[subscript 2]O emissions, in particular in South Asia (20 ± 3% of global total), South America (13 ± 4%) and Africa (19 ± 3%), while emissions from temperate regions were smaller: Europe (6 ± 1%) and North America (7 ± 2%). A significant multi-annual trend in N[subscript 2]O emissions (0.045 Tg a[superscript −2] N) from South Asia was found and confirms inventory estimates of this trend. Considerable interannual variability in the global N[subscript 2]O source was observed (0.8 Tg a[superscript −1] N, 1 standard deviation, SD) and was largely driven by variability in tropical and subtropical soil fluxes, in particular in South America (0.3 Tg a[superscript −1] N, 1 SD) and Africa (0.3 Tg a[superscript −1] N, 1 SD). Notable variability was also found for N[subscript 2]O fluxes in the tropical and southern oceans (0.15 and 0.2 Tg a[superscript −1] N, 1 SD, respectively). Interannual variability in the N[subscript 2]O source shows some correlation with the El Niño–Southern Oscillation (ENSO), where El Niño conditions are associated with lower N[subscript 2]O fluxes from soils and from the ocean and vice versa for La Niña conditions.
Published: 2014

29. Global and regional emissions estimates for N[subscript 2]O

Author: Massachusetts Institute of Technology. Center for Global Change Science, Saikawa, Eri, Prinn, Ronald G., Dlugokencky, E., Ishijima, K., Dutton, G. S., Hall, B. D., Langenfelds, R. L., Tohjima, Y., Machida, Toshinobu, Manizza, Manfredi, Rigby, M., O'Doherty, Simon, Patra, P. K., Harth, C. M., Weiss, R. F., Krummel, P. B., van der Schoot, M., Fraser, P. J., Steele, L. P., Aoki, S., Nakazawa, T., Elkins, J. W., Massachusetts Institute of Technology. Center for Global Change Science, Saikawa, Eri, Prinn, Ronald G., Dlugokencky, E., Ishijima, K., Dutton, G. S., Hall, B. D., Langenfelds, R. L., Tohjima, Y., Machida, Toshinobu, Manizza, Manfredi, Rigby, M., O'Doherty, Simon, Patra, P. K., Harth, C. M., Weiss, R. F., Krummel, P. B., van der Schoot, M., Fraser, P. J., Steele, L. P., Aoki, S., Nakazawa, T., and Elkins, J. W.
Abstract: We present a comprehensive estimate of nitrous oxide (N[subscript 2]O) emissions using observations and models from 1995 to 2008. High-frequency records of tropospheric N[subscript 2]O are available from measurements at Cape Grim, Tasmania; Cape Matatula, American Samoa; Ragged Point, Barbados; Mace Head, Ireland; and at Trinidad Head, California using the Advanced Global Atmospheric Gases Experiment (AGAGE) instrumentation and calibrations. The Global Monitoring Division of the National Oceanic and Atmospheric Administration/Earth System Research Laboratory (NOAA/ESRL) has also collected discrete air samples in flasks and in situ measurements from remote sites across the globe and analyzed them for a suite of species including N[subscript 2]O. In addition to these major networks, we include in situ and aircraft measurements from the National Institute of Environmental Studies (NIES) and flask measurements from the Tohoku University and Commonwealth Scientific and Industrial Research Organization (CSIRO) networks. All measurements show increasing atmospheric mole fractions of N[subscript 2]O, with a varying growth rate of 0.1–0.7% per year, resulting in a 7.4% increase in the background atmospheric mole fraction between 1979 and 2011. Using existing emission inventories as well as bottom-up process modeling results, we first create globally gridded a priori N[subscript 2]O emissions over the 37 years since 1975. We then use the three-dimensional chemical transport model, Model for Ozone and Related Chemical Tracers version 4 (MOZART v4), and a Bayesian inverse method to estimate global as well as regional annual emissions for five source sectors from 13 regions in the world. This is the first time that all of these measurements from multiple networks have been combined to determine emissions. Our inversion indicates that global and regional N[subscript 2]O emissions have an increasing trend between 1995 and 2008. Despite large uncertainties, a significant increase i, NASA Upper Atmospheric Research Program (Grant NNX11AF17G), NASA Upper Atmospheric Research Program (Grant NNX07AF09G), NASA Upper Atmospheric Research Program (Grant NNX07AE87G), United States. National Oceanic and Atmospheric Administration (Contract RA133R09CN0062)
Published: 2014

30. Interannual variability in tropospheric nitrous oxide

Author: Massachusetts Institute of Technology. Center for Global Change Science, Prinn, Ronald G., Thompson, R. L., Dlugokencky, E., Chevallier, F., Ciais, P., Dutton, G. S., Elkins, J. W., Langenfelds, R. L., Weiss, R. F., Tohjima, Y., O'Doherty, Simon, Krummel, P. B., Fraser, P. J., Steele, L. P., Massachusetts Institute of Technology. Center for Global Change Science, Prinn, Ronald G., Thompson, R. L., Dlugokencky, E., Chevallier, F., Ciais, P., Dutton, G. S., Elkins, J. W., Langenfelds, R. L., Weiss, R. F., Tohjima, Y., O'Doherty, Simon, Krummel, P. B., Fraser, P. J., and Steele, L. P.
Abstract: Observations of tropospheric N2O mixing ratio show significant variability on interannual timescales (0.2 ppb, 1 standard deviation). We found that interannual variability in N2O is weakly correlated with that in CFC-12 and SF6 for the northern extratropics and more strongly correlated for the southern extratropics, suggesting that interannual variability in all these species is influenced by large-scale atmospheric circulation changes and, for SF6 in particular, interhemispheric transport. N2O interannual variability was not, however, correlated with polar lower stratospheric temperature, which is used as a proxy for stratosphere-to-troposphere transport in the extratropics. This suggests that stratosphere-to-troposphere transport is not a dominant factor in year-to-year variations in N2O growth rate. Instead, we found strong correlations of N2O interannual variability with the Multivariate ENSO Index. The climate variables, precipitation, soil moisture, and temperature were also found to be significantly correlated with N2O interannual variability, suggesting that climate-driven changes in soil N2O flux may be important for variations in N2O growth rate., European Research Council (EU Seventh Research Framework Programme (grant agreement 283576, MACC-II)), Research Council of Norway (contract 193774, SOGG-EA)
Published: 2014

31. Stratospheric lifetime ratio of CFC-11 and CFC-12 from satellite and model climatologies

Author: Hoffmann, L., primary, Hoppe, C. M., additional, Müller, R., additional, Dutton, G. S., additional, Gille, J. C., additional, Griessbach, S., additional, Jones, A., additional, Meyer, C. I., additional, Spang, R., additional, Volk, C. M., additional, and Walker, K. A., additional
Published: 2014
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32. Supplementary material to "Stratospheric lifetime ratio of CFC-11 and CFC-12 from satellite and model climatologies"

Author: Hoffmann, L., primary, Hoppe, C. M., additional, Müller, R., additional, Dutton, G. S., additional, Gille, J. C., additional, Griessbach, S., additional, Jones, A., additional, Meyer, C. I., additional, Spang, R., additional, Volk, C. M., additional, and Walker, K. A., additional
Published: 2014
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33. Re-evaluation of the lifetimes of the major CFCs and CH[subscript 3]CCl[subscript 3] using atmospheric trends

Author: Massachusetts Institute of Technology. Center for Global Change Science, Rigby, Matthew, Prinn, Ronald G., O'Doherty, Simon, Montzka, Stephen A., McCulloch, A., Harth, C. M., Muhle, Jens, Salameh, P. K., Weiss, R. F., Young, D., Simmonds, P. G., Hall, B. D., Dutton, G. S., Nance, D., Mondeel, D. J., Elkins, J. W., Krummel, P. B., Steele, L. P., Fraser, P. J., Massachusetts Institute of Technology. Center for Global Change Science, Rigby, Matthew, Prinn, Ronald G., O'Doherty, Simon, Montzka, Stephen A., McCulloch, A., Harth, C. M., Muhle, Jens, Salameh, P. K., Weiss, R. F., Young, D., Simmonds, P. G., Hall, B. D., Dutton, G. S., Nance, D., Mondeel, D. J., Elkins, J. W., Krummel, P. B., Steele, L. P., and Fraser, P. J.
Abstract: Since the Montreal Protocol on Substances that Deplete the Ozone Layer and its amendments came into effect, growth rates of the major ozone depleting substances (ODS), particularly CFC-11, -12 and -113 and CH[subscript 3]CCl[subscript 3], have declined markedly, paving the way for global stratospheric ozone recovery. Emissions have now fallen to relatively low levels, therefore the rate at which this recovery occurs will depend largely on the atmospheric lifetime of these compounds. The first ODS measurements began in the early 1970s along with the first lifetime estimates calculated by considering their atmospheric trends. We now have global mole fraction records spanning multiple decades, prompting this lifetime re-evaluation. Using surface measurements from the Advanced Global Atmospheric Gases Experiment (AGAGE) and the National Oceanic and Atmospheric Administration Global Monitoring Division (NOAA GMD) from 1978 to 2011, we estimated the lifetime of CFC-11, CFC-12, CFC-113 and CH[subscript 3]CCl[subscript 3] using a multi-species inverse method. A steady-state lifetime of 45 yr for CFC-11, currently recommended in the most recent World Meteorological Organisation (WMO) Scientific Assessments of Ozone Depletion, lies towards the lower uncertainty bound of our estimates, which are 54[61 over 48] yr (1-sigma uncertainty) when AGAGE data were used and 52[61 over 45] yr when the NOAA network data were used. Our derived lifetime for CFC-113 is significantly higher than the WMO estimates of 85 yr, being 109[121 over 99] (AGAGE) and 109[124 over 97] (NOAA). New estimates of the steady-state lifetimes of CFC-12 and CH[subscript 3]CCl[subscript 3] are consistent with the current WMO recommendations, being 111[132 over 95] and 112[136 over 95] yr (CFC-12, AGAGE and NOAA respectively) and 5.04[5.20 over 4.92] and 5.04[5.23 over 4.87] yr (CH[subscript 3]CCl[subscript 3], AGAGE and NOAA respectively)., NASA Upper Atmospheric Research Program (Advanced Global Atmospheric Gases Experiment (AGAGE) Grant NNX07AE89G), NASA Upper Atmospheric Research Program (Advanced Global Atmospheric Gases Experiment (AGAGE) Grant NNX11AF17G)
Published: 2013

34. History of atmospheric SF6 [SF subscript 6] from 1973 to 2008

Author: Massachusetts Institute of Technology. Center for Global Change Science, Prinn, Ronald G., Rigby, Matthew, Muhle, Jens, Miller, Benjamin R., Krummel, P. B., Steele, L. P., Fraser, P. J., Salameh, P. K., Harth, C. M., Weiss, R. F., Greally, B. R., O'Doherty, Simon, Simmonds, P. G., Vollmer, M. K., Reimann, S., Kim, J., Kim, K.-R., Wang, H. J., Olivier, Jos G. J., Dlugokencky, E., Dutton, G. S., Hall, B. D., Elkins, J. W., Massachusetts Institute of Technology. Center for Global Change Science, Prinn, Ronald G., Rigby, Matthew, Muhle, Jens, Miller, Benjamin R., Krummel, P. B., Steele, L. P., Fraser, P. J., Salameh, P. K., Harth, C. M., Weiss, R. F., Greally, B. R., O'Doherty, Simon, Simmonds, P. G., Vollmer, M. K., Reimann, S., Kim, J., Kim, K.-R., Wang, H. J., Olivier, Jos G. J., Dlugokencky, E., Dutton, G. S., Hall, B. D., and Elkins, J. W.
Abstract: We present atmospheric sulfur hexafluoride (SF6)[SF subscript 6] mole fractions and emissions estimates from the 1970s to 2008. Measurements were made of archived air samples starting from 1973 in the Northern Hemisphere and from 1978 in the Southern Hemisphere, using the Advanced Global Atmospheric Gases Experiment (AGAGE) gas chromatographic-mass spectrometric (GC-MS) systems. These measurements were combined with modern high-frequency GC-MS and GC-electron capture detection (ECD) data from AGAGE monitoring sites, to produce a unique 35-year atmospheric record of this potent greenhouse gas. Atmospheric mole fractions were found to have increased by more than an order of magnitude between 1973 and 2008. The 2008 growth rate was the highest recorded, at 0.29 ± 0.02 pmolmol−1 [pmolmol superscript -1] yr−1 [yr superscript -1]. A three-dimensional chemical transport model and a minimum variance Bayesian inverse method was used to estimate annual emission rates using the measurements, with a priori estimates from the Emissions Database for Global Atmospheric Research (EDGAR, version 4). Consistent with the mole fraction growth rate maximum, global emissions during 2008 were also the highest in the 1973–2008 period, reaching 7.4 ± 0.6 Gg yr−1 [yr superscript -1] (1-σ [1 - delta] uncertainties) and surpassing the previous maximum in 1995. The 2008 values follow an increase in emissions of 48 ± 20% since 2001. A second global inversion which also incorporated National Oceanic and Atmospheric Administration (NOAA) flask measurements and in situ monitoring site data agreed well with the emissions derived using AGAGE measurements alone. By estimating continent-scale emissions using all available AGAGE and NOAA surface measurements covering the period 2004–2008, with no pollution filtering, we find that it is likely that much of the global emissions rise during this five-year period originated primarily from Asian developing countries that do not report detailed, annual emissi, NASA Upper Atmospheric Research Program (Grant NNX07AE89G), NASA Upper Atmospheric Research Program (Grant NNX07AF09G), NASA Upper Atmospheric Research Program (Grant NNX07AE87G), Great Britain. Dept. for Environment, Food & Rural Affairs, United States. National Oceanic and Atmospheric Administration, Commonwealth Scientific and Industrial Research Organization (Australia), Australia. Bureau of Meteorology, Korea. Meteorological Administration. Research and Development Program (Grant CATER 2009-4109)
Published: 2011

35. Atmospheric three-dimensional inverse modeling of regional industrial emissions and global oceanic uptake of carbon tetrachloride

Author: Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Prinn, Ronald G., Xiao, X., Golombek, Amram, Fraser, P. J., Weiss, R. F., Simmonds, P. G., O'Doherty, Simon, Miller, Benjamin R., Salameh, P. K., Harth, C. M., Krummel, P. B., Porter, L. W., Butler, J. H., Elkins, J. W., Dutton, G. S., Hall, B. D., Steele, L. P., Wang, R. H. J., Cunnold, D. M., Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Prinn, Ronald G., Xiao, X., Golombek, Amram, Fraser, P. J., Weiss, R. F., Simmonds, P. G., O'Doherty, Simon, Miller, Benjamin R., Salameh, P. K., Harth, C. M., Krummel, P. B., Porter, L. W., Butler, J. H., Elkins, J. W., Dutton, G. S., Hall, B. D., Steele, L. P., Wang, R. H. J., and Cunnold, D. M.
Abstract: Carbon tetrachloride (CCl4) has substantial stratospheric ozone depletion potential and its consumption is controlled under the Montreal Protocol and its amendments. We implement a Kalman filter using atmospheric CCl4 measurements and a 3-dimensional chemical transport model to estimate the interannual regional industrial emissions and seasonal global oceanic uptake of CCl4 for the period of 1996–2004. The Model of Atmospheric Transport and Chemistry (MATCH), driven by offline National Center for Environmental Prediction (NCEP) reanalysis meteorological fields, is used to simulate CCl4 mole fractions and calculate their sensitivities to regional sources and sinks using a finite difference approach. High frequency observations from the Advanced Global Atmospheric Gases Experiment (AGAGE) and the Earth System Research Laboratory (ESRL) of the National Oceanic and Atmospheric Administration (NOAA) and low frequency flask observations are together used to constrain the source and sink magnitudes, estimated as factors that multiply the a priori fluxes. Although industry data imply that the global industrial emissions were substantially declining with large interannual variations, the optimized results show only small interannual variations and a small decreasing trend. The global surface CCl4 mole fractions were declining in this period because the CCl4 oceanic and stratospheric sinks exceeded the industrial emissions. Compared to the a priori values, the inversion results indicate substantial increases in industrial emissions originating from the South Asian/Indian and Southeast Asian regions, and significant decreases in emissions from the European and North American regions., United States. National Aeronautics and Space Administration (Grant NNX07AE89G), United States. National Aeronautics and Space Administration (Grant NAG5-12669), United States. National Aeronautics and Space Administration (Grant NAG5-12099), National Science Foundation (U.S.) (grant ATM-0120468), United States. National Aeronautics and Space Administration (Grant NNX07AF09G), United States. National Aeronautics and Space Administration (Grant NNX07AE87G), Great Britain. Department for Environment, Food and Rural Affairs (grants EPG 1/1/159), Great Britain. Department for Environment, Food and Rural Affairs (grant CPEG 24), Great Britain. Department for Environment, Food and Rural Affairs (grants GA01081), Australia. Bureau of Meteorology, CSIRO Marine and Atmospheric Research
Published: 2011

36. Optimal estimation of the surface fluxes of methyl chloride using a 3-D global chemical transport model

Author: Massachusetts Institute of Technology. Center for Global Change Science, Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Prinn, Ronald G., Xiao, Xue, Fraser, P. J., Simmonds, P. G., Weiss, R. F., O'Doherty, Simon, Miller, Benjamin R., Salameh, P. K., Harth, C. M., Krummel, P. B., Porter, L. W., Muhle, B. R., Greally, B. R., Cunnold, D. M., Wang, R., Montzka, Stephen A., Elkins, J. W., Dutton, G. S., Thompson, T. M., Butler, J. H., Hall, B. D., Reimann, S., Vollmer, M. K., Stordal, F., Lunder, Chris R., Maione, Michela, Arduini, J., Yakouchi, Y., Massachusetts Institute of Technology. Center for Global Change Science, Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Prinn, Ronald G., Xiao, Xue, Fraser, P. J., Simmonds, P. G., Weiss, R. F., O'Doherty, Simon, Miller, Benjamin R., Salameh, P. K., Harth, C. M., Krummel, P. B., Porter, L. W., Muhle, B. R., Greally, B. R., Cunnold, D. M., Wang, R., Montzka, Stephen A., Elkins, J. W., Dutton, G. S., Thompson, T. M., Butler, J. H., Hall, B. D., Reimann, S., Vollmer, M. K., Stordal, F., Lunder, Chris R., Maione, Michela, Arduini, J., and Yakouchi, Y.
Abstract: Methyl chloride (CH3Cl) [CH subscript 3 Cl] is a chlorine-containing trace gas in the atmosphere contributing significantly to stratospheric ozone depletion. Large uncertainties in estimates of its source and sink magnitudes and temporal and spatial variations currently exist. GEIA inventories and other bottom-up emission estimates are used to construct a priori maps of the surface fluxes of CH3Cl [CH subscript 3 Cl]. The Model of Atmospheric Transport and Chemistry (MATCH), driven by NCEP interannually varying meteorological data, is then used to simulate CH3Cl [CH subscript 3 Cl] mole fractions and quantify the time series of sensitivities of the mole fractions at each measurement site to the surface fluxes of various regional and global sources and sinks. We then implement the Kalman filter (with the unit pulse response method) to estimate the surface fluxes on regional/global scales with monthly resolution from January 2000 to December 2004. High frequency observations from the AGAGE, SOGE, NIES, and NOAA/ESRL HATS in situ networks and low frequency observations from the NOAA/ESRL HATS flask network are used to constrain the source and sink magnitudes. The inversion results indicate global total emissions around 4100 ± 470 Gg yr−1 [yr superscript -1] with very large emissions of 2200 ± 390 Gg yr−1 [yr superscript -1] from tropical plants, which turn out to be the largest single source in the CH3Cl [CH subscript 3 Cl] budget. Relative to their a priori annual estimates, the inversion increases global annual fungal and tropical emissions, and reduces the global oceanic source. The inversion implies greater seasonal and interannual oscillations of the natural sources and sink of CH3Cl [CH subscript 3 Cl] compared to the a priori. The inversion also reflects the strong effects of the 2002/2003 globally widespread heat waves and droughts on global emissions from tropical plants, biomass burning and salt marshes, and on the soil sink., United States. National Aeronautics and Space Administration (Grant NNX07AE89G), United States. National Aeronautics and Space Administration (Grant NAG5-12669), United States. National Aeronautics and Space Administration (Grant NNX07AF09G), United States. National Aeronautics and Space Administration (Grant NNX07AE87G), National Science Foundation (U.S.) (Grant ATM-0120468), United States. National Aeronautics and Space Administration (Grant NAG5-12099)
Published: 2011

37. Exploring causes of interannual variability in the seasonal cycles of tropospheric nitrous oxide

Author: Massachusetts Institute of Technology. Center for Global Change Science, Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Prinn, Ronald G., Nevison, C. D., Dlugokencky, E., Dutton, G. S., Elkins, J. W., Fraser, P. J., Hall, B. D., Krummel, P. B., Langenfelds, R. L., O'Doherty, Simon, Steele, L. P., Weiss, R. F., Prinn, Ronald G, Massachusetts Institute of Technology. Center for Global Change Science, Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences, Prinn, Ronald G., Nevison, C. D., Dlugokencky, E., Dutton, G. S., Elkins, J. W., Fraser, P. J., Hall, B. D., Krummel, P. B., Langenfelds, R. L., O'Doherty, Simon, Steele, L. P., Weiss, R. F., and Prinn, Ronald G
Abstract: Seasonal cycles in the mixing ratios of tropospheric nitrous oxide (N[subscript 2]O) are derived by detrending long-term measurements made at sites across four global surface monitoring networks. The detrended monthly data display large interannual variability, which at some sites challenges the concept of a "mean" seasonal cycle. In the Northern Hemisphere, correlations between polar winter lower stratospheric temperature and detrended N[subscript 2]O data, around the month of the seasonal minimum, provide empirical evidence for a stratospheric influence, which varies in strength from year to year and can explain much of the interannual variability in the surface seasonal cycle. Even at sites where a strong, competing, regional N[subscript 2]O source exists, such as from coastal upwelling at Trinidad Head, California, the stratospheric influence must be understood to interpret the biogeochemical signal in monthly mean data. In the Southern Hemisphere, detrended surface N[subscript 2]O monthly means are correlated with polar spring lower stratospheric temperature in months preceding the N[subscript 2]O minimum, providing empirical evidence for a coherent stratospheric influence in that hemisphere as well, in contrast to some recent atmospheric chemical transport model (ACTM) results. Correlations between the phasing of the surface N[subscript 2]O seasonal cycle in both hemispheres and both polar lower stratospheric temperature and polar vortex break-up date provide additional support for a stratospheric influence. The correlations discussed above are generally more evident in high-frequency in situ data than in data from weekly flask samples. Furthermore, the interannual variability in the N[subscript 2]O seasonal cycle is not always correlated among in situ and flask networks that share common sites, nor do the mean seasonal amplitudes always agree. The importance of abiotic influences such as the stratospheric influx and tropospheric transport on N[subscript 2]O s, United States. National Aeronautics and Space Administration (grant NNX08AB48G)
Published: 2011

38. Tropospheric SF6: Age of air from the Northern Hemisphere midlatitude surface

Author: Waugh, D. W., primary, Crotwell, A. M., additional, Dlugokencky, E. J., additional, Dutton, G. S., additional, Elkins, J. W., additional, Hall, B. D., additional, Hintsa, E. J., additional, Hurst, D. F., additional, Montzka, S. A., additional, Mondeel, D. J., additional, Moore, F. L., additional, Nance, J. D., additional, Ray, E. A., additional, Steenrod, S. D., additional, Strahan, S. E., additional, and Sweeney, C., additional
Published: 2013
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39. Interannual fluctuations in the seasonal cycle of nitrous oxide and chlorofluorocarbons due to the Brewer-Dobson circulation

Author: Simmonds, P. G., primary, Manning, A. J., additional, Athanassiadou, M., additional, Scaife, A. A., additional, Derwent, R. G., additional, O'Doherty, S., additional, Harth, C. M., additional, Weiss, R. F., additional, Dutton, G. S., additional, Hall, B. D., additional, Sweeney, C., additional, and Elkins, J. W., additional
Published: 2013
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40. Global and regional emissions estimates for N2O

Author: Saikawa, E., primary, Prinn, R. G., additional, Dlugokencky, E., additional, Ishijima, K., additional, Dutton, G. S., additional, Hall, B. D., additional, Langenfelds, R., additional, Tohjima, Y., additional, Machida, T., additional, Manizza, M., additional, Rigby, M., additional, O'Doherty, S., additional, Patra, P. K., additional, Harth, C. M., additional, Weiss, R. F., additional, Krummel, P. B., additional, van der Schoot, M., additional, Fraser, P. B., additional, Steele, L. P., additional, Aoki, S., additional, Nakazawa, T., additional, and Elkins, J. W., additional
Published: 2013
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41. Re-evaluation of the lifetimes of the major CFCs and CH3CCl3 using atmospheric trends

Author: Rigby, M., primary, Prinn, R. G., additional, O'Doherty, S., additional, Montzka, S. A., additional, McCulloch, A., additional, Harth, C. M., additional, Mühle, J., additional, Salameh, P. K., additional, Weiss, R. F., additional, Young, D., additional, Simmonds, P. G., additional, Hall, B. D., additional, Dutton, G. S., additional, Nance, D., additional, Mondeel, D. J., additional, Elkins, J. W., additional, Krummel, P. B., additional, Steele, L. P., additional, and Fraser, P. J., additional
Published: 2013
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42. MIPAS IMK/IAA CFC-11 (CCl3F) and CFC-12 (CCl2F2) measurements: accuracy, precision and long-term stability.

Author: Eckert, E., Laeng, A., Lossow, S., Kellmann, S., Stiller, G., von Clarmann, T., Glatthor, N., Höpfner, M., Kiefer, M., Oelhaf, H., Orphal, J., Funke, B., Grabowski, U., Haenel, F., Linden, A., Wetzel, G., Woiwode, W., Bernath, P. F., Boone, C., and Dutton, G. S.
Subjects: CHLOROFLUOROCARBONS & the environment, PASSIVE solar energy systems, METEOROLOGICAL satellites, OZONE layer depletion, OZONE layer protection
Abstract: Profiles of CFC-11 (CCl3F) and CFC-12 (CCl2F2) of the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) aboard the European satellite Envisat have been retrieved from versions MIPAS/4.61 to MIPAS/4.62 and MIPAS/5.02 to MIPAS/5.06 level-1b data using the scientific level-2 processor run by Karlsruhe Institute of Technology (KIT), Institute of Meteorology and Climate Research (IMK) and Consejo Superior de Investigaciones Científicas (CSIC), Instituto de Astrofísica de Andalucía (IAA). These profiles have been compared to measurements taken by the balloon-borne cryosampler, Mark IV (MkIV) and MIPAS-Balloon (MIPAS-B), the airborne MIPAS-STRatospheric aircraft (MIPAS-STR), the satellite-borne Atmospheric Chemistry Experiment Fourier transform spectrometer (ACE-FTS) and the High Resolution Dynamic Limb Sounder (HIRDLS), as well as the ground-based Halocarbon and other Atmospheric Trace Species (HATS) network for the reduced spectral resolution period (RR: January 2005–April 2012) of MIPAS. ACE-FTS, MkIV and HATS also provide measurements during the high spectral resolution period (full resolution, FR: July 2002–March 2004) and were used to validate MIPAS CFC-11 and CFC-12 products during that time, as well as profiles from the Improved Limb Atmospheric Spectrometer, ILAS-II. In general, we find that MIPAS shows slightly higher values for CFC-11 at the lower end of the profiles (below ∼  15 km) and in a comparison of HATS ground-based data and MIPAS measurements at 3 km below the tropopause. Differences range from approximately 10 to 50 pptv ( ∼  5–20 %) during the RR period. In general, differences are slightly smaller for the FR period. An indication of a slight high bias at the lower end of the profile exists for CFC-12 as well, but this bias is far less pronounced than for CFC-11 and is not as obvious in the relative differences between MIPAS and any of the comparison instruments. Differences at the lower end of the profile (below ∼  15 km) and in the comparison of HATS and MIPAS measurements taken at 3 km below the tropopause mainly stay within 10–50 pptv (corresponding to ∼  2–10 % for CFC-12) for the RR and the FR period. Between ∼  15 and 30 km, most comparisons agree within 10–20 pptv (10–20 %), apart from ILAS-II, which shows large differences above ∼  17 km. Overall, relative differences are usually smaller for CFC-12 than for CFC-11. For both species – CFC-11 and CFC-12 – we find that differences at the lower end of the profile tend to be larger at higher latitudes than in tropical and subtropical regions. In addition, MIPAS profiles have a maximum in their mixing ratio around the tropopause, which is most obvious in tropical mean profiles. Comparisons of the standard deviation in a quiescent atmosphere (polar summer) show that only the CFC-12 FR error budget can fully explain the observed variability, while for the other products (CFC-11 FR and RR and CFC-12 RR) only two-thirds to three-quarters can be explained. Investigations regarding the temporal stability show very small negative drifts in MIPAS CFC-11 measurements. These instrument drifts vary between ∼  1 and 3 % decade−1. For CFC-12, the drifts are also negative and close to zero up to ∼  30 km. Above that altitude, larger drifts of up to ∼  50 % decade−1 appear which are negative up to ∼  35 km and positive, but of a similar magnitude, above. [ABSTRACT FROM AUTHOR]
Published: 2016
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43. Global CFC-11 (CCl3F) and CFC-12 (CCl2F2) measurements with the Michelson Interferometer for Passive Atmospheric Sounding (MIPAS): retrieval, climatologies and trends

Author: Kellmann, S., primary, von Clarmann, T., additional, Stiller, G. P., additional, Eckert, E., additional, Glatthor, N., additional, Höpfner, M., additional, Kiefer, M., additional, Orphal, J., additional, Funke, B., additional, Grabowski, U., additional, Linden, A., additional, Dutton, G. S., additional, and Elkins, J. W., additional
Published: 2012
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44. Re-evaluation of the lifetimes of the major CFCs and CH3CCl3 using atmospheric trends

Author: Rigby, M., primary, Prinn, R. G., additional, O'Doherty, S., additional, Montzka, S. A., additional, McCulloch, A., additional, Harth, C. M., additional, Mühle, J., additional, Salameh, P. K., additional, Weiss, R. F., additional, Young, D., additional, Simmonds, P. G., additional, Hall, B. D., additional, Dutton, G. S., additional, Nance, D., additional, Mondeel, D. J., additional, Elkins, J. W., additional, Krummel, P. B., additional, Steele, L. P., additional, and Fraser, P. J., additional
Published: 2012
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45. Supplementary material to "Re-evaluation of the lifetimes of the major CFCs and CH3CCl3 using atmospheric trends"

Author: Rigby, M., primary, Prinn, R. G., additional, O'Doherty, S., additional, Montzka, S. A., additional, McCulloch, A., additional, Harth, C. M., additional, Mühle, J., additional, Salameh, P. K., additional, Weiss, R. F., additional, Young, D., additional, Simmonds, P. G., additional, Hall, B. D., additional, Dutton, G. S., additional, Nance, D., additional, Mondeel, D. J., additional, Elkins, J. W., additional, Krummel, P. B., additional, Steele, L. P., additional, and Fraser, P. J., additional
Published: 2012
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46. Improving measurements of SF6 for the study of atmospheric transport and emissions

Author: Hall, B. D., primary, Dutton, G. S., additional, Mondeel, D. J., additional, Nance, J. D., additional, Rigby, M., additional, Butler, J. H., additional, Moore, F. L., additional, Hurst, D. F., additional, and Elkins, J. W., additional
Published: 2011
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47. Supplementary material to "Improving measurements of SF6 for the study of atmospheric transport and emissions"

Author: Hall, B. D., primary, Dutton, G. S., additional, Mondeel, D. J., additional, Nance, J. D., additional, Rigby, M., additional, Butler, J. H., additional, Moore, F. L., additional, Hurst, D. F., additional, and Elkins, J. W., additional
Published: 2011
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48. Chlorine budget and partitioning during the Stratospheric Aerosol and Gas Experiment (SAGE) III Ozone Loss and Validation Experiment (SOLVE)

Author: Schauffler, S. M., Schauffler, S. M., Atlas, E. L., Donnelly, S. G., Andrews, A., Montzka, S. A., Elkins, J. W., Hurst, D. F., Romashkin, P. A., Dutton, G. S., Stroud, V., Schauffler, S. M., Schauffler, S. M., Atlas, E. L., Donnelly, S. G., Andrews, A., Montzka, S. A., Elkins, J. W., Hurst, D. F., Romashkin, P. A., Dutton, G. S., and Stroud, V.
Abstract: The amount of chlorine in the stratosphere has a direct influence on the magnitude of chlorine-catalyzed ozone loss. A comprehensive suite of organic source gases of chlorine in the stratosphere was measured during the NASA Stratospheric Aerosol and Gas Experiment (SAGE) III Ozone Loss and Validation Experiment (SOLVE) campaign in the arctic winter of 2000. Measurements included chlorofluorocarbons (CFCs), hydrochlorofluorocarbons (HCFCs), halon 1211, solvents, methyl chloride, N2O, and CH4. Inorganic chlorine contributions from each compound were calculated using the organic chlorine measurements, mean age of air, tropospheric trends, and a method to account for mixing in the stratosphere. Total organic chlorine measured at tropospheric levels of N2O was on the order of 3500 ppt. Total calculated inorganic chlorine at a N2O mixing ratio of 50 ppb (corresponding to a mean age of 5.5 years) was on the order of 3400 ppt. CFCs were the largest contributors to total organic chlorine (55-70%) over the measured N2O range (50-315 ppb), followed by CH3Cl (15%), solvents (5-20%), and HCFCs (5-25%). CH3Cl contribution was consistently about 15% across the organic chlorine range. Contributions to total calculated inorganic chlorine at 50 ppb N2O were 58% from CFCs, 24% from solvents, 16% from CH3Cl, and 2% from HCFCs. Updates to fractional chlorine release values for each compound relative to CFC 11 were calculated from the SOLVE measurements. An average value of 0.58 was calculated for the fractional chlorine release of CFC 11 over the 3-4 year mean age range, which was lower than the previous value of 0.80. The fractional chlorine release values for HCFCs 141b and 142b relative to CFC 11 were significantly lower than previous calculations.
Published: 2003

49. The diurnal variation of hydrogen, nitrogen, and chlorine radicals: implications for the heterogeneous production of HNO_2

Author: Salawitch, R. J., Wofsy, S. C., Wennberg, P. O., Cohen, R. C., Anderson, J. G., Fahey, D. W., Gao, R. S., Keim, E. R., Woodbridge, E. L., Stimpfle, R. M., Koplow, J. P., Kohn, D. W., Webster, C. R., May, R. D., Pfister, L., Gottlieb, E. W., Michelsen, H. A., Yue, G. K., Prather, M. J., Wilson, J. C., Brock, C. A., Jonsson, H. H., Dye, J. E., Baumgardner, D., Proffitt, M. H., Loewenstein, M., Podolske, J. R., Elkins, J. W., Dutton, G. S., Hintsa, E. J., Dessler, A. E., Weinstock, E. M., Kelly, K. K., Boering, K. A., Daube, B. C., Chan, K. R., and Bowen, S. W.
Abstract: In situ measurements of hydrogen, nitrogen, and chlorine radicals obtained through sunrise and sunset in the lower stratosphere during SPADE are compared to results from a photochemical model constrained by observed concentrations of radical precursors and environmental conditions. Models allowing for heterogeneous hydrolysis of N_(2)O_(5) on sulfate aerosols agree with measured concentrations of NO, NO_(2), and ClO throughout the day, but fail to account for high concentrations of OH and HO_(2) observed near sunrise and sunset. The morning burst of [OH] and [HO_(2)] coincides with the rise of [NO] from photolysis of NO_(2), suggesting a new source of HO_(x) that photolyzes in the near UV (350 to 400 nm) spectral region. A model that allows for the heterogeneous production of HNO_(2) results in an excellent simulation of the diurnal variations of [OH] and [HO_(2)].
Published: 1994

50. The distribution of hydrogen, nitrogen, and chlorine radicals in the lower stratosphere: Implications for changes in O_3 due to emission of NO_y from supersonic aircraft

Author: Salawitch, R. J., Wofsy, S. C., Wennberg, P. O., Cohen, R. C., Anderson, J. G., Fahey, D. W., Gao, R. S., Keim, E. R., Woodbridge, E. L., Stimpfle, R. M., Koplow, J. P., Kohn, D. W., Webster, C. R., May, R. D., Pfister, L., Gottlieb, E. W., Michelsen, H. A., Yue, G. K., Wilson, J. C., Brock, C. A., Jonsson, H. H., Dye, J. E., Baumgardner, D., Proffitt, M. H., Loewenstein, M., Podolske, J. R., Elkins, J. W., Dutton, G. S., Hintsa, E. J., Dessler, A. E., Weinstock, E. M., Kelly, K. K., Boering, K. A., Daube, B. C., Chan, K. R., and Bowen, S. W.
Abstract: In situ measurements of hydrogen, nitrogen, and chlorine radicals obtained in the lower stratosphere during SPADE are compared to results from a photochemical model that assimilates measurements of radical precursors and environmental conditions. Models allowing for heterogeneous hydrolysis of N_2O_5 agree well with measured concentrations of NO and ClO, but concentrations of HO_2 and OH are underestimated by 10 to 25%, concentrations of NO_2 are overestimated by 10 to 30%, and concentrations of HCl are overestimated by a factor of 2. Discrepancies for [OH] and [HO_2] are reduced if we allow for higher yields of O(^1D) from O_3 photolysis and for heterogeneous production of HNO_2. The data suggest more efficient catalytic removal of O_3 by hydrogen and halogen radicals relative to nitrogen oxide radicals than predicted by models using recommended rates and cross sections. Increases in [O_3] in the lower stratosphere may be larger in response to inputs of NO_y from supersonic aircraft than estimated by current assessment models.
Published: 1994

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