45 results on '"Fried, Alan"'
Search Results
2. Observations of atmospheric oxidation and ozone production in South Korea
- Author
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Brune, William H., Miller, David O., Thames, Alexander B., Brosius, Alexandra L., Barletta, Barbara, Blake, Donald R., Blake, Nicola J., Chen, Gao, Choi, Yonghoon, Crawford, James H., Digangi, Joshua P., Diskin, Glenn, Fried, Alan, Hall, Samuel R., Hanisco, Thomas F., Huey, Greg L., Hughes, Stacey C., Kim, Michelle, Meinardi, Simone, Montzka, Denise D., Pusede, Sally E., Schroeder, Jason R., Teng, Alex, Tanner, David J., Ullmann, Kirk, Walega, James, Weinheimer, Andrew, Wisthaler, Armin, and Wennberg, Paul O.
- Published
- 2022
- Full Text
- View/download PDF
3. Sensitivity of the WRF-Chem v4.4 simulations of ozone and formaldehyde and their precursors to multiple bottom-up emission inventories over East Asia during the KORUS-AQ 2016 field campaign
- Author
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Kim, Kyoung-Min, primary, Kim, Si-Wan, additional, Seo, Seunghwan, additional, Blake, Donald R., additional, Cho, Seogju, additional, Crawford, James H., additional, Emmons, Louisa K., additional, Fried, Alan, additional, Herman, Jay R., additional, Hong, Jinkyu, additional, Jung, Jinsang, additional, Pfister, Gabriele G., additional, Weinheimer, Andrew J., additional, Woo, Jung-Hun, additional, and Zhang, Qiang, additional
- Published
- 2024
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- View/download PDF
4. Impact of improved representation of VOC emissions and production of NOx reservoirs on modeled urban ozone production.
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Travis, Katherine R., Nault, Benjamin A., Crawford, James H., Bates, Kelvin H., Blake, Donald R., Cohen, Ronald C., Fried, Alan, Hall, Samuel R., Huey, L. Greg, Lee, Young Ro, Meinardi, Simone, Min, Kyung-Eun, Simpson, Isobel J., and Ullman, Kirk
- Subjects
ACETALDEHYDE ,POLYACRYLONITRILES ,ENVIRONMENTAL research ,OZONE ,LIQUEFIED petroleum gas ,PEROXYACETYL nitrate ,VOLATILE organic compounds - Abstract
The fraction of urban volatile organic compounds (VOC) emissions attributable to fossil fuel combustion has been declining in many parts of the world, resulting in a need to better constrain other anthropogenic sources of these emissions. During the National Institute of Environmental Research (NIER) and National Aeronautics and Space Administration (NASA) Korea-United States Air Quality (KORUS-AQ) field study in Seoul, South Korea during May–June 2016, air quality models underestimated ozone, formaldehyde, and peroxyacetyl nitrate (PAN) indicating an underestimate of VOCs in the emissions inventory. Here, we use aircraft observations interpreted with the GEOS-Chem chemical transport model to assess the need for increases in VOC emissions. We find that the largest increases are attributable to compounds associated with volatile chemical products, liquefied petroleum gas (LPG) and natural gas emissions, and long-range transport. Revising model chemistry to better match observed VOC speciation together with increasing model emissions of underestimated VOC species increased calculated OH reactivity by +2 s
-1 and ozone production by 2 ppb hr-1 . Ozone increased by 6 ppb below 2 km and 9 ppb at the surface, and formaldehyde and acetaldehyde increased by 30 % and 120 % aloft, respectively, all in better agreement with observations. The larger increase in acetaldehyde was attributed to ethanol emissions which we found to be as important for ozone production as isoprene or alkenes. The increased acetaldehyde largely resolved the model PAN bias. The need for additional unmeasured VOCs however was indicated by a remaining model bias of -1 ppb in formaldehyde and 57 % and 52 % underestimate in higher peroxynitrates (PNs) and alkyl nitrates (ANs), respectively. We added additional chemistry to the model to represent an additional six PNs from observed VOCs but were unable to account for the majority of missing PNs. However, four of these PNs were modeled at concentrations similar to other commonly measured PNs (>2 % of PAN) indicating that these should be measured in future campaigns. We hypothesize that emissions of oxygenated VOCs (OVOCs) such as >C5 aldehydes from cooking and/or alkenes associated with volatile chemical products could produce both PNs and ANs and improve remaining model biases. Emerging research on the emissions and chemistry of these species will soon allow for modeling of their impact on local and regional photochemistry. [ABSTRACT FROM AUTHOR]- Published
- 2024
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5. Parameterizations of US wildfire and prescribed fire emission ratios and emission factors based on FIREX-AQ aircraft measurements.
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Gkatzelis, Georgios I., Coggon, Matthew M., Stockwell, Chelsea E., Hornbrook, Rebecca S., Allen, Hannah, Apel, Eric C., Bela, Megan M., Blake, Donald R., Bourgeois, Ilann, Brown, Steven S., Campuzano-Jost, Pedro, St. Clair, Jason M., Crawford, James H., Crounse, John D., Day, Douglas A., DiGangi, Joshua P., Diskin, Glenn S., Fried, Alan, Gilman, Jessica B., and Guo, Hongyu
- Subjects
PRESCRIBED burning ,FLAME ,FIRE management ,COMBUSTION efficiency ,WILDFIRES ,CARBONACEOUS aerosols ,AIR quality - Abstract
Extensive airborne measurements of non-methane organic gases (NMOGs), methane, nitrogen oxides, reduced nitrogen species, and aerosol emissions from US wild and prescribed fires were conducted during the 2019 NOAA/NASA Fire Influence on Regional to Global Environments and Air Quality campaign (FIREX-AQ). Here, we report the atmospheric enhancement ratios (ERs) and inferred emission factors (EFs) for compounds measured on board the NASA DC-8 research aircraft for nine wildfires and one prescribed fire, which encompass a range of vegetation types. We use photochemical proxies to identify young smoke and reduce the effects of chemical degradation on our emissions calculations. ERs and EFs calculated from FIREX-AQ observations agree within a factor of 2, with values reported from previous laboratory and field studies for more than 80 % of the carbon- and nitrogen-containing species. Wildfire emissions are parameterized based on correlations of the sum of NMOGs with reactive nitrogen oxides (NO y) to modified combustion efficiency (MCE) as well as other chemical signatures indicative of flaming/smoldering combustion, including carbon monoxide (CO), nitrogen dioxide (NO 2), and black carbon aerosol. The sum of primary NMOG EFs correlates to MCE with an R2 of 0.68 and a slope of - 296 ± 51 g kg -1 , consistent with previous studies. The sum of the NMOG mixing ratios correlates well with CO with an R2 of 0.98 and a slope of 137 ± 4 ppbv of NMOGs per parts per million by volume (ppmv) of CO, demonstrating that primary NMOG emissions can be estimated from CO. Individual nitrogen-containing species correlate better with NO 2 , NO y , and black carbon than with CO. More than half of the NO y in fresh plumes is NO 2 with an R2 of 0.95 and a ratio of NO 2 to NO y of 0.55 ± 0.05 ppbv ppbv -1 , highlighting that fast photochemistry had already occurred in the sampled fire plumes. The ratio of NO y to the sum of NMOGs follows trends observed in laboratory experiments and increases exponentially with MCE, due to increased emission of key nitrogen species and reduced emission of NMOGs at higher MCE during flaming combustion. These parameterizations will provide more accurate boundary conditions for modeling and satellite studies of fire plume chemistry and evolution to predict the downwind formation of secondary pollutants, including ozone and secondary organic aerosol. [ABSTRACT FROM AUTHOR]
- Published
- 2024
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- View/download PDF
6. Emission Factors for Crop Residue and Prescribed Fires in the Eastern US During FIREX‐AQ
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Travis, Katherine R., primary, Crawford, James. H., additional, Soja, Amber J., additional, Gargulinski, Emily M., additional, Moore, Richard H., additional, Wiggins, Elizabeth B., additional, Diskin, Glenn S., additional, DiGangi, Joshua P., additional, Nowak, John B., additional, Halliday, Hannah, additional, Yokelson, Robert J., additional, McCarty, Jessica L., additional, Simpson, Isobel J., additional, Blake, Donald R., additional, Meinardi, Simone, additional, Hornbrook, Rebecca S., additional, Apel, Eric C., additional, Hills, Alan J., additional, Warneke, Carsten, additional, Coggon, Matthew M., additional, Rollins, Andrew W., additional, Gilman, Jessica B., additional, Womack, Caroline C., additional, Robinson, Michael A., additional, Katich, Joseph M., additional, Peischl, Jeff, additional, Gkatzelis, Georgios I., additional, Bourgeois, Ilann, additional, Rickly, Pamela S., additional, Lamplugh, Aaron, additional, Dibb, Jack E., additional, Jimenez, Jose L., additional, Campuzano‐Jost, Pedro, additional, Day, Douglas A., additional, Guo, Hongyu, additional, Pagonis, Demetrios, additional, Wennberg, Paul O., additional, Crounse, John D., additional, Xu, Lu, additional, Hanisco, Thomas F., additional, Wolfe, Glenn M., additional, Liao, Jin, additional, St. Clair, Jason M., additional, Nault, Benjamin A., additional, Fried, Alan, additional, and Perring, Anne E., additional
- Published
- 2023
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7. Sensitivity of the WRF-Chem v4.4 ozone, formaldehyde, and precursor simulations to multiple bottom-up emission inventories over East Asia during the KORUS-AQ 2016 field campaign
- Author
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Kim, Kyoung-Min, primary, Kim, Si-Wan, additional, Seo, Seunghwan, additional, Blake, Donald R., additional, Cho, Seogju, additional, Crawford, James H., additional, Emmons, Louisa, additional, Fried, Alan, additional, Herman, Jay R., additional, Hong, Jinkyu, additional, Jung, Jinsang, additional, Pfister, Gabriele, additional, Weinheimer, Andrew J., additional, Woo, Jung-Hun, additional, and Zhang, Qiang, additional
- Published
- 2023
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8. Supplementary material to "Sensitivity of the WRF-Chem v4.4 ozone, formaldehyde, and precursor simulations to multiple bottom-up emission inventories over East Asia during the KORUS-AQ 2016 field campaign"
- Author
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Kim, Kyoung-Min, primary, Kim, Si-Wan, additional, Seo, Seunghwan, additional, Blake, Donald R., additional, Cho, Seogju, additional, Crawford, James H., additional, Emmons, Louisa, additional, Fried, Alan, additional, Herman, Jay R., additional, Hong, Jinkyu, additional, Jung, Jinsang, additional, Pfister, Gabriele, additional, Weinheimer, Andrew J., additional, Woo, Jung-Hun, additional, and Zhang, Qiang, additional
- Published
- 2023
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9. Comparison of Urban Air Quality Simulations During the KORUS‐AQ Campaign With Regionally Refined Versus Global Uniform Grids in the Multi‐Scale Infrastructure for Chemistry and Aerosols (MUSICA) Version 0
- Author
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Jo, Duseong S., primary, Emmons, Louisa K., additional, Callaghan, Patrick, additional, Tilmes, Simone, additional, Woo, Jung‐Hun, additional, Kim, Younha, additional, Kim, Jinseok, additional, Granier, Claire, additional, Soulié, Antonin, additional, Doumbia, Thierno, additional, Darras, Sabine, additional, Buchholz, Rebecca R., additional, Simpson, Isobel J., additional, Blake, Donald R., additional, Wisthaler, Armin, additional, Schroeder, Jason R., additional, Fried, Alan, additional, and Kanaya, Yugo, additional
- Published
- 2023
- Full Text
- View/download PDF
10. Parameterizations of US wildfire and prescribed fire emission ratios and emission factors based on FIREX-AQ aircraft measurements
- Author
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Gkatzelis, Georgios I., Coggon, Matthew M., Stockwell, Chelsea E., Hornbrook, Rebecca S., Allen, Hannah, Apel, Eric C., Ball, Katherine, Bela, Megan M., Blake, Donald R., Bourgeois, Ilann, Brown, Steven S., Campuzano-Jost, Pedro, Clair, Jason M., Crawford, James H., Crounse, John D., Day, Douglas A., DiGangi, Joshua, Diskin, Glenn, Fried, Alan, Gilman, Jessica, Guo, Hongyu, Hair, Johnathan W., Halliday, Hannah A., Hanisco, Thomas F., Hannun, Reem, Hills, Alan, Huey, Gregory, Jimenez, Jose L., Katich, Joseph M., Lamplugh, Aaron, Lee, Young Ro, Liao, Jin, Lindaas, Jakob, McKeen, Stuart A., Mikoviny, Tomas, Nault, Benjamin A., Neuman, James A., Nowak, John B., Pagonis, Demetrios, Peischl, Jeff, Perring, Anne E., Piel, Felix, Rickly, Pamela S., Robinson, Michael A., Rollins, Andrew W., Ryerson, Thomas B., Schueneman, Melinda K., Schwantes, Rebecca H., Schwarz, Joshua P., Sekimoto, Kanako, Selimovic, Vanessa, Shingler, Taylor, Tanner, David J., Tomsche, Laura, Vasquez, Krystal, Veres, Patrick R., Washenfelder, Rebecca, Weibring, Petter, Wennberg, Paul O., Wisthaler, Armin, Wolfe, Glenn, Womack, Caroline, Xu, Lu, Yokelson, Robert, and Warneke, Carsten
- Abstract
Extensive airborne measurements of non-methane organic gases (NMOGs), methane, nitrogen oxides, reduced nitrogen-species, and aerosol emissions from US wild and prescribed fires were conducted during the 2019 NOAA/NASA Fire Influence on Regional to Global Environments and Air Quality campaign (FIREX-AQ). Here, we report the atmospheric enhancement ratios (ERs) and inferred emission factors (EFs) for compounds measured onboard the NASA DC-8 research aircraft for nine wildfires and one prescribed fire, which encompass a range of vegetation types. We use photochemical proxies to identify young smoke and reduce the effects of chemical degradation on our emissions calculations. ERs and EFs calculated from FIREX-AQ observations agree within a factor of 2 with values reported from previous laboratory and field studies for more than 80 % of the carbon- and nitrogen-containing species. Wildfire emissions are parameterized based on correlations of the sum of NMOGs with reactive nitrogen oxides (NOy) to modified combustion efficiency (MCE) as well as other chemical signatures indicative of flaming/smoldering combustion, including carbon monoxide (CO), nitrogen dioxide (NO2), and black carbon aerosol. The sum of primary NMOG EFs correlates to MCE with an R2 of 0.68 and a slope of -296 ± 51 g kg-1, consistent with previous studies. The sum of the NMOG mixing ratios correlates well with CO with an R2 of 0.98 and a slope of 137 ± 4 ppbv of NMOGs per ppmv of CO, demonstrating that primary NMOG emissions can be estimated from CO. Individual nitrogen-containing species correlate better with NO2, NOy, and black carbon than with CO. More than half of the NOy in fresh plumes is NO2 with an R2 of 0.95 and a ratio of NO2 to NOy of 0.55 ± 0.05 ppbv ppbv-1, highlighting that fast photochemistry had already occurred in the sampled fire plumes. The ratio of NOy to the sum of NMOGs follows trends observed in laboratory experiments and increases exponentially with MCE, due to increased emission of key nitrogen species and reduced emission of NMOGs at higher MCE during flaming combustion. These parameterizations will provide more accurate boundary conditions for modeling and satellite studies of fire plume chemistry and evolution to predict the downwind formation of secondary pollutants, including ozone and secondary organic aerosol.
- Published
- 2023
11. Constraining emissions of volatile organic compounds from western US wildfires with WE-CAN and FIREX-AQ airborne observations
- Author
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Jin, Lixu, primary, Permar, Wade, additional, Selimovic, Vanessa, additional, Ketcherside, Damien, additional, Yokelson, Robert J., additional, Hornbrook, Rebecca S., additional, Apel, Eric C., additional, Ku, I-Ting, additional, Collett Jr., Jeffrey L., additional, Sullivan, Amy P., additional, Jaffe, Daniel A., additional, Pierce, Jeffrey R., additional, Fried, Alan, additional, Coggon, Matthew M., additional, Gkatzelis, Georgios I., additional, Warneke, Carsten, additional, Fischer, Emily V., additional, and Hu, Lu, additional
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- 2023
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12. Comment on amt-2023-83
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Fried, Alan, primary
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- 2023
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13. Exploring the influence of rigid carbocycles on terpenoid copolymer properties
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Galan, Nicholas J., primary, Fried, Alan D., additional, Cromer, Chase E., additional, Fish, Abigail, additional, Coughlin, Dominic R., additional, and Brantley, Johnathan N., additional
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- 2023
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14. Evaluation of the emission inventory for large point emission sources in South Korea by applying measured data from the NASA/NIER KORUS-AQ aircraft field campaign
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Park, Minwoo, primary, Hu, Hyejung, additional, Kim, Younha, additional, Fried, Alan, additional, Simpson, Isobel J., additional, Jin, Hyungah, additional, Weinheimer, Andrew, additional, Huey, Greg, additional, Crawford, James, additional, and Woo, Jung-Hun, additional
- Published
- 2023
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15. Sensitivity of the WRF-Chem v4.4 ozone, formaldehyde, and precursor simulations to multiple bottom-up emission inventories over East Asia during the KORUS-AQ 2016 field campaign.
- Author
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Kyoung-Min Kim, Si-Wan Kim, Seunghwan Seo, Blake, Donald R., Seogju Cho, Crawford, James H., Emmons, Louisa, Fried, Alan, Herman, Jay R., Jinkyu Hong, Jinsang Jung, Pfister, Gabriele, Weinheimer, Andrew J., Jung-Hun Woo, and Qiang Zhang
- Subjects
EMISSION inventories ,OZONE ,FORMALDEHYDE ,METROPOLITAN areas ,AIR quality ,MODEL airplanes - Abstract
In this study, the WRF-Chem v4.4 model was utilized to evaluate three bottom-up emission inventories (EDGAR-HTAP v2, v3, and KORUS v5) using surface and aircraft data in East Asia during the Korea-United States Air Quality (KORUS-AQ) campaign period in 2016. All emission inventories were found to reproduce the diurnal variations of O3 and NO2 as compared to the surface monitor data. However, the spatial distributions of the daily maximum 8-hour average (MDA8) O3 in the model do not completely align with the observations. The model MDA8 O
3 had a negative (positive) bias north (south) of 30°N over China. All simulations underestimated the observed CO by 50-60% over China and South Korea. In the Seoul Metropolitan Area (SMA), EDGAR-HTAP v2, v3, and KORUS v5 simulated the vertical shapes and diurnal patterns of O3 and other precursors effectively, but the model underestimated the observed O3 , CO and HCHO concentrations. Notably, the model aromatic VOCs were significantly underestimated with the three bottom-up emission inventories, although the KORUS v5 shows improvements. The model isoprene estimations had a positive bias relative to the observations, suggesting that the Model of Emissions of Gases and Aerosols from Nature (MEGAN) version 2.04 overestimated isoprene emissions. Additional model simulations were conducted by doubling CO and VOC emissions over China and South Korea to investigate the causes of the model O3 biases and the effects of the long-range transport on the O3 over South Korea. The doubled CO and VOC emission simulations improved the model O3 simulations for the local emission dominant case, but led to the model O3 overestimations for the transport dominant case, which emphasizes the need for accurate representations of the local VOC emissions over South Korea. [ABSTRACT FROM AUTHOR]- Published
- 2023
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16. Comment on amt-2022-294
- Author
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Fried, Alan, primary
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- 2022
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17. Supplementary material to "Constraining emissions of volatile organic compounds from western US wildfires with WE-CAN and FIREX-AQ airborne observations"
- Author
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Jin, Lixu, primary, Permar, Wade, additional, Selimovic, Vanessa, additional, Ketcherside, Damien, additional, Yokelson, Robert J., additional, Hornbrook, Rebecca S., additional, Apel, Eric C., additional, Ku, I-Ting, additional, Collett Jr., Jeffrey L., additional, Sullivan, Amy P., additional, Jaffe, Daniel A., additional, Pierce, Jeffrey R., additional, Fried, Alan, additional, Coggon, Matthew M., additional, Gkatzelis, Georgios I., additional, Warneke, Carsten, additional, Fischer, Emily V., additional, and Hu, Lu, additional
- Published
- 2022
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18. Constraining emissions of volatile organic compounds from western US wildfires with WE-CAN and FIREX-AQ airborne observations
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Jin, Lixu, primary, Permar, Wade, additional, Selimovic, Vanessa, additional, Ketcherside, Damien, additional, Yokelson, Robert J., additional, Hornbrook, Rebecca S., additional, Apel, Eric C., additional, Ku, I-Ting, additional, Collett Jr., Jeffrey L., additional, Sullivan, Amy P., additional, Jaffe, Daniel A., additional, Pierce, Jeffrey R., additional, Fried, Alan, additional, Coggon, Matthew M., additional, Gkatzelis, Georgios I., additional, Warneke, Carsten, additional, Fischer, Emily V., additional, and Hu, Lu, additional
- Published
- 2022
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19. Atmospheric biogenic volatile organic compounds in the Alaskan Arctic tundra: constraints from measurements at Toolik Field Station
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Selimovic, Vanessa, primary, Ketcherside, Damien, additional, Chaliyakunnel, Sreelekha, additional, Wielgasz, Catherine, additional, Permar, Wade, additional, Angot, Hélène, additional, Millet, Dylan B., additional, Fried, Alan, additional, Helmig, Detlev, additional, and Hu, Lu, additional
- Published
- 2022
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20. Composition and reactivity of volatile organic compounds in the South Coast Air Basin and San Joaquin Valley of California
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Liu, Shang, primary, Barletta, Barbara, additional, Hornbrook, Rebecca S., additional, Fried, Alan, additional, Peischl, Jeff, additional, Meinardi, Simone, additional, Coggon, Matthew, additional, Lamplugh, Aaron, additional, Gilman, Jessica B., additional, Gkatzelis, Georgios I., additional, Warneke, Carsten, additional, Apel, Eric C., additional, Hills, Alan J., additional, Bourgeois, Ilann, additional, Walega, James, additional, Weibring, Petter, additional, Richter, Dirk, additional, Kuwayama, Toshihiro, additional, FitzGibbon, Michael, additional, and Blake, Donald, additional
- Published
- 2022
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21. Characterization of Errors in Satellite-based HCHO / NO2 Tropospheric Column Ratios with Respect to Chemistry, Column to PBL Translation, Spatial Representation, and Retrieval Uncertainties
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Souri, Amir H., primary, Johnson, Matthew S., additional, Wolfe, Glenn M., additional, Crawford, James H., additional, Fried, Alan, additional, Wisthaler, Armin, additional, Brune, William H., additional, Blake, Donald R., additional, Weinheimer, Andrew J., additional, Verhoelst, Tijl, additional, Compernolle, Steven, additional, Pinardi, Gaia, additional, Vigouroux, Corinne, additional, Langerock, Bavo, additional, Choi, Sungyeon, additional, Lamsal, Lok, additional, Zhu, Lei, additional, Sun, Shuai, additional, Cohen, Ronald C., additional, Min, Kyung-Eun, additional, Cho, Changmin, additional, Philip, Sajeev, additional, Liu, Xiong, additional, and Chance, Kelly, additional
- Published
- 2022
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22. Supplementary material to "Characterization of Errors in Satellite-based HCHO / NO2 Tropospheric Column Ratios with Respect to Chemistry, Column to PBL Translation, Spatial Representation, and Retrieval Uncertainties"
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Souri, Amir H., primary, Johnson, Matthew S., additional, Wolfe, Glenn M., additional, Crawford, James H., additional, Fried, Alan, additional, Wisthaler, Armin, additional, Brune, William H., additional, Blake, Donald R., additional, Weinheimer, Andrew J., additional, Verhoelst, Tijl, additional, Compernolle, Steven, additional, Pinardi, Gaia, additional, Vigouroux, Corinne, additional, Langerock, Bavo, additional, Choi, Sungyeon, additional, Lamsal, Lok, additional, Zhu, Lei, additional, Sun, Shuai, additional, Cohen, Ronald C., additional, Min, Kyung-Eun, additional, Cho, Changmin, additional, Philip, Sajeev, additional, Liu, Xiong, additional, and Chance, Kelly, additional
- Published
- 2022
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23. Can Column Formaldehyde Observations Inform Air Quality Monitoring Strategies for Ozone and Related Photochemical Oxidants?
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Travis, K. R., primary, Judd, L. M., additional, Crawford, J. H., additional, Chen, Gao, additional, Szykman, James, additional, Whitehill, Andrew, additional, Valin, Lukas C., additional, Spinei, Elena, additional, Janz, Scott, additional, Nowlan, Caroline R., additional, Kwon, Hyeong‐Ahn, additional, Fried, Alan, additional, and Walega, James, additional
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- 2022
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24. Supplementary material to "Atmospheric biogenic volatile organic compounds in the Alaskan Arctic tundra: constraints from measurements at Toolik Field Station"
- Author
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Selimovic, Vanessa, primary, Ketcherside, Damien, additional, Chaliyakunnel, Sreelekha, additional, Wielgasz, Catie, additional, Permar, Wade, additional, Angot, Hélène, additional, Millet, Dylan B., additional, Fried, Alan, additional, Helmig, Detlev, additional, and Hu, Lu, additional
- Published
- 2022
- Full Text
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25. Supplementary material to "Composition and Reactivity of Volatile Organic Compounds in the South Coast Air Basin and San Joaquin Valley of California"
- Author
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Liu, Shang, primary, Barletta, Barbara, additional, Hornbrook, Rebecca S., additional, Fried, Alan, additional, Peischl, Jeff, additional, Meinardi, Simone, additional, Coggon, Matthew, additional, Lamplugh, Aaron, additional, Gilman, Jessica B., additional, Gkatzelis, Georgios I., additional, Warneke, Carsten, additional, Apel, Eric C., additional, Hills, Alan J., additional, Bourgeois, Ilann, additional, Walega, James, additional, Weibring, Petter, additional, Richter, Dirk, additional, Kuwayama, Toshihiro, additional, FitzGibbon, Michael, additional, and Blake, Donald, additional
- Published
- 2022
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26. Airborne Emission Rate Measurements Validate Remote Sensing Observations and Emission Inventories of Western U.S. Wildfires
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Stockwell, Chelsea E., primary, Bela, Megan M., additional, Coggon, Matthew M., additional, Gkatzelis, Georgios I., additional, Wiggins, Elizabeth, additional, Gargulinski, Emily M., additional, Shingler, Taylor, additional, Fenn, Marta, additional, Griffin, Debora, additional, Holmes, Christopher D., additional, Ye, Xinxin, additional, Saide, Pablo E., additional, Bourgeois, Ilann, additional, Peischl, Jeff, additional, Womack, Caroline C., additional, Washenfelder, Rebecca A., additional, Veres, Patrick R., additional, Neuman, J. Andrew, additional, Gilman, Jessica B., additional, Lamplugh, Aaron, additional, Schwantes, Rebecca H., additional, McKeen, Stuart A., additional, Wisthaler, Armin, additional, Piel, Felix, additional, Guo, Hongyu, additional, Campuzano-Jost, Pedro, additional, Jimenez, Jose L., additional, Fried, Alan, additional, Hanisco, Thomas F., additional, Huey, Lewis Gregory, additional, Perring, Anne, additional, Katich, Joseph M., additional, Diskin, Glenn S., additional, Nowak, John B., additional, Bui, T. Paul, additional, Halliday, Hannah S., additional, DiGangi, Joshua P., additional, Pereira, Gabriel, additional, James, Eric P., additional, Ahmadov, Ravan, additional, McLinden, Chris A., additional, Soja, Amber J., additional, Moore, Richard H., additional, Hair, Johnathan W., additional, and Warneke, Carsten, additional
- Published
- 2022
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27. Electroediting of Soft Polymer Backbones
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Fried, Alan D., primary, Wilson, Breana J., additional, Galan, Nicholas J., additional, and Brantley, Johnathan N., additional
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- 2022
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28. Photochemical evolution of the 2013 California Rim Fire: synergistic impacts of reactive hydrocarbons and enhanced oxidants
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Wolfe, Glenn M., primary, Hanisco, Thomas F., additional, Arkinson, Heather L., additional, Blake, Donald R., additional, Wisthaler, Armin, additional, Mikoviny, Tomas, additional, Ryerson, Thomas B., additional, Pollack, Ilana, additional, Peischl, Jeff, additional, Wennberg, Paul O., additional, Crounse, John D., additional, St. Clair, Jason M., additional, Teng, Alex, additional, Huey, L. Gregory, additional, Liu, Xiaoxi, additional, Fried, Alan, additional, Weibring, Petter, additional, Richter, Dirk, additional, Walega, James, additional, Hall, Samuel R., additional, Ullmann, Kirk, additional, Jimenez, Jose L., additional, Campuzano-Jost, Pedro, additional, Bui, T. Paul, additional, Diskin, Glenn, additional, Podolske, James R., additional, Sachse, Glen, additional, and Cohen, Ronald C., additional
- Published
- 2022
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29. Observed versus simulated OH reactivity during KORUS-AQ campaign: Implications for emission inventory and chemical environment in East Asia
- Author
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Kim, Hyeonmin, Park, Rokjin J., Kim, Saewung, Brune, William H., Diskin, Glenn S., Fried, Alan, Hall, Samuel R., Weinheimer, Andrew J., Wennberg, Paul, Wisthaler, Armin, Blake, Donald R., and Ullmann, Kirk
- Subjects
Atmospheric Science ,Environmental Engineering ,Ecology ,Geology ,Geotechnical Engineering and Engineering Geology ,Oceanography - Abstract
We present a holistic examination of tropospheric OH reactivity (OHR) in South Korea using comprehensive NASA DC-8 airborne measurements collected during the Korea–United States Air Quality field study and chemical transport models. The observed total OHR (tOHR) averaged in the planetary boundary layer (PBL
- Published
- 2022
30. Characterization of errors in satellite-based HCHO / NO2 tropospheric column ratios with respect to chemistry, column-to-PBL translation, spatial representation, and retrieval uncertainties.
- Author
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Souri, Amir H., Johnson, Matthew S., Wolfe, Glenn M., Crawford, James H., Fried, Alan, Wisthaler, Armin, Brune, William H., Blake, Donald R., Weinheimer, Andrew J., Verhoelst, Tijl, Compernolle, Steven, Pinardi, Gaia, Vigouroux, Corinne, Langerock, Bavo, Choi, Sungyeon, Lamsal, Lok, Zhu, Lei, Sun, Shuai, Cohen, Ronald C., and Min, Kyung-Eun
- Subjects
TROPOSPHERIC aerosols ,ATMOSPHERIC boundary layer ,INNER cities ,GAUSSIAN distribution ,NITROGEN dioxide ,VOLATILE organic compounds ,SAMPLING errors - Abstract
The availability of formaldehyde (HCHO) (a proxy for volatile organic compound reactivity) and nitrogen dioxide (NO 2) (a proxy for nitrogen oxides) tropospheric columns from ultraviolet–visible (UV–Vis) satellites has motivated many to use their ratios to gain some insights into the near-surface ozone sensitivity. Strong emphasis has been placed on the challenges that come with transforming what is being observed in the tropospheric column to what is actually in the planetary boundary layer (PBL) and near the surface; however, little attention has been paid to other sources of error such as chemistry, spatial representation, and retrieval uncertainties. Here we leverage a wide spectrum of tools and data to quantify those errors carefully. Concerning the chemistry error, a well-characterized box model constrained by more than 500 h of aircraft data from NASA's air quality campaigns is used to simulate the ratio of the chemical loss of HO 2 + RO 2 (LROx) to the chemical loss of NO x (LNOx). Subsequently, we challenge the predictive power of HCHO/NO2 ratios (FNRs), which are commonly applied in current research, in detecting the underlying ozone regimes by comparing them to LROx/LNOx. FNRs show a strongly linear (R2=0.94) relationship with LROx/LNOx , but only on the logarithmic scale. Following the baseline (i.e., ln(LROx/LNOx) = - 1.0 ± 0.2) with the model and mechanism (CB06, r2) used for segregating NOx -sensitive from VOC-sensitive regimes, we observe a broad range of FNR thresholds ranging from 1 to 4. The transitioning ratios strictly follow a Gaussian distribution with a mean and standard deviation of 1.8 and 0.4, respectively. This implies that the FNR has an inherent 20 % standard error (1σ) resulting from not accurately describing the ROx – HOx cycle. We calculate high ozone production rates (PO 3) dominated by large HCHO × NO 2 concentration levels, a new proxy for the abundance of ozone precursors. The relationship between PO 3 and HCHO × NO 2 becomes more pronounced when moving towards NOx -sensitive regions due to nonlinear chemistry; our results indicate that there is fruitful information in the HCHO × NO 2 metric that has not been utilized in ozone studies. The vast amount of vertical information on HCHO and NO 2 concentrations from the air quality campaigns enables us to parameterize the vertical shapes of FNRs using a second-order rational function permitting an analytical solution for an altitude adjustment factor to partition the tropospheric columns into the PBL region. We propose a mathematical solution to the spatial representation error based on modeling isotropic semivariograms. Based on summertime-averaged data, the Ozone Monitoring Instrument (OMI) loses 12 % of its spatial information at its native resolution with respect to a high-resolution sensor like the TROPOspheric Monitoring Instrument (TROPOMI) (> 5.5 × 3.5 km 2). A pixel with a grid size of 216 km 2 fails at capturing ∼ 65 % of the spatial information in FNRs at a 50 km length scale comparable to the size of a large urban center (e.g., Los Angeles). We ultimately leverage a large suite of in situ and ground-based remote sensing measurements to draw the error distributions of daily TROPOMI and OMI tropospheric NO 2 and HCHO columns. At a 68 % confidence interval (1σ), errors pertaining to daily TROPOMI observations, either HCHO or tropospheric NO 2 columns, should be above 1.2–1.5 × 10 16 molec. cm -2 to attain a 20 %–30 % standard error in the ratio. This level of error is almost non-achievable with the OMI given its large error in HCHO. The satellite column retrieval error is the largest contributor to the total error (40 %–90 %) in the FNRs. Due to a stronger signal in cities, the total relative error (< 50 %) tends to be mild, whereas areas with low vegetation and anthropogenic sources (e.g., the Rocky Mountains) are markedly uncertain (> 100 %). Our study suggests that continuing development in the retrieval algorithm and sensor design and calibration is essential to be able to advance the application of FNRs beyond a qualitative metric. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
31. Reactive halogen chemistry in the Arctic boundary layer over snow during spring: A 1D modelling case study
- Author
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Ahmed, Shaddy, primary, Thomas, Jennie L., additional, Tuite, Katie, additional, Stutz, Jochen, additional, Flocke, Frank, additional, Orlando, John J., additional, Hornbrook, Rebecca S., additional, Apel, Eric C., additional, Emmons, Louisa K., additional, Helmig, Detlev, additional, Boylan, Patrick, additional, Huey, L. Gregory, additional, Hall, Samuel R., additional, Ullmann, Kirk, additional, Cantrell, Christopher A., additional, and Fried, Alan, additional
- Published
- 2022
- Full Text
- View/download PDF
32. The Role of Snow in Controlling Halogen Chemistry and Boundary Layer Oxidation During Arctic Spring: A 1D Modeling Case Study
- Author
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Ahmed, Shaddy, primary, Thomas, Jennie L., additional, Tuite, Katie, additional, Stutz, Jochen, additional, Flocke, Frank, additional, Orlando, John J., additional, Hornbrook, Rebecca S., additional, Apel, Eric C., additional, Emmons, Louisa K., additional, Helmig, Detlev, additional, Boylan, Patrick, additional, Huey, L. Gregory, additional, Hall, Samuel R., additional, Ullmann, Kirk, additional, Cantrell, Christopher A., additional, and Fried, Alan, additional
- Published
- 2022
- Full Text
- View/download PDF
33. Field observational constraints on the controllers in glyoxal (CHOCHO) reactive uptake to aerosol
- Author
-
Kim, Dongwook, primary, Cho, Changmin, additional, Jeong, Seokhan, additional, Lee, Soojin, additional, Nault, Benjamin A., additional, Campuzano-Jost, Pedro, additional, Day, Douglas A., additional, Schroder, Jason C., additional, Jimenez, Jose L., additional, Volkamer, Rainer, additional, Blake, Donald R., additional, Wisthaler, Armin, additional, Fried, Alan, additional, DiGangi, Joshua P., additional, Diskin, Glenn S., additional, Pusede, Sally E., additional, Hall, Samuel R., additional, Ullmann, Kirk, additional, Huey, L. Gregory, additional, Tanner, David J., additional, Dibb, Jack, additional, Knote, Christoph J., additional, and Min, Kyung-Eun, additional
- Published
- 2022
- Full Text
- View/download PDF
34. An investigation of petrochemical emissions during KORUS-AQ: Ozone production, reactive nitrogen evolution, and aerosol production
- Author
-
Lee, Young Ro, primary, Huey, L. Gregory, additional, Tanner, David J., additional, Takeuchi, Masayuki, additional, Qu, Hang, additional, Liu, Xiaoxi, additional, Ng, Nga Lee, additional, Crawford, James H., additional, Fried, Alan, additional, Richter, Dirk, additional, Simpson, Isobel J., additional, Blake, Donald R., additional, Blake, Nicola J., additional, Meinardi, Simone, additional, Kim, Saewung, additional, Diskin, Glenn S., additional, Digangi, Joshua P., additional, Choi, Yonghoon, additional, Pusede, Sally E., additional, Wennberg, Paul O., additional, Kim, Michelle J., additional, Crounse, John D., additional, Teng, Alex P., additional, Cohen, Ronald C., additional, Romer, Paul S., additional, Brune, William, additional, Wisthaler, Armin, additional, Mikoviny, Tomas, additional, Jimenez, Jose L., additional, Campuzano-Jost, Pedro, additional, Nault, Benjamin A., additional, Weinheimer, Andrew, additional, Hall, Samuel R., additional, and Ullmann, Kirk, additional
- Published
- 2022
- Full Text
- View/download PDF
35. The role of snow in controlling halogen chemistry and boundary layer oxidation during Arctic spring: A 1D modelling case study
- Author
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Ahmed, Shaddy, Thomas, Jennie L., Tuite, Katie, Stutz, Jochen, Flocke, Frank, Orlando, John J., Hornbrook, Rebecca S., Apel, Eric C., Emmons, Louisa K., Helmig, Detlev, Boylan, Patrick, Huey, L. Gregory, Hall, Samuel R., Ullmann, Kirk, Cantrell, Christopher A., Fried, Alan, Institut des Géosciences de l’Environnement (IGE), Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Grenoble Alpes (UGA)-Institut polytechnique de Grenoble - Grenoble Institute of Technology (Grenoble INP ), and Université Grenoble Alpes (UGA)
- Subjects
Atmospheric Science ,atmospheric chemistry ,Geophysics ,Arctic ,Space and Planetary Science ,[SDU]Sciences of the Universe [physics] ,Earth and Planetary Sciences (miscellaneous) ,halogens ,modeling ,snow emissions - Abstract
International audience; Reactive chlorine and bromine species emitted from snow and aerosols can significantly alter the oxidative capacity of the polar boundary layer. However, halogen production mechanisms from snow remain highly uncertain, making it difficult for most models to include descriptions of halogen snow emissions and to understand the impact on atmospheric chemistry. We investigate the influence of Arctic halogen emissions from snow on boundary layer oxidation processes using a one-dimensional atmospheric chemistry and transport model (PACT-1D). To understand the combined impact of snow emissions and boundary layer dynamics on atmospheric chemistry, we model Cl2 and Br2 primary emissions from snow and include heterogeneous recycling of halogens on both snow and aerosols. We focus on a 2-day case study from the 2009 Ocean-Atmosphere-Sea Ice-Snowpack campaign at Utqiaġvik, Alaska. The model reproduces both the diurnal cycle and high quantity of Cl2 observed, along with the measured concentrations of Br2, BrO, and HOBr. Due to the combined effects of emissions, recycling, vertical mixing, and atmospheric chemistry, reactive chlorine is typically confined to the lowest 15 m of the atmosphere, while bromine can impact chemistry up to and above the surface inversion height. Upon including halogen emissions and recycling, the concentration of HOx (HOx = OH + HO2) at the surface increases by as much as a factor of 30 at mid-day. The change in HOx due to halogen chemistry, as well as chlorine atoms derived from snow emissions, significantly reduce volatile organic compound lifetimes within a shallow layer near the surface.
- Published
- 2021
36. Formaldehyde evolution in US wildfire plumes during the Fire Influence on Regional to Global Environments and Air Quality experiment (FIREX-AQ)
- Author
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Liao, Jin, primary, Wolfe, Glenn M., additional, Hannun, Reem A., additional, St. Clair, Jason M., additional, Hanisco, Thomas F., additional, Gilman, Jessica B., additional, Lamplugh, Aaron, additional, Selimovic, Vanessa, additional, Diskin, Glenn S., additional, Nowak, John B., additional, Halliday, Hannah S., additional, DiGangi, Joshua P., additional, Hall, Samuel R., additional, Ullmann, Kirk, additional, Holmes, Christopher D., additional, Fite, Charles H., additional, Agastra, Anxhelo, additional, Ryerson, Thomas B., additional, Peischl, Jeff, additional, Bourgeois, Ilann, additional, Warneke, Carsten, additional, Coggon, Matthew M., additional, Gkatzelis, Georgios I., additional, Sekimoto, Kanako, additional, Fried, Alan, additional, Richter, Dirk, additional, Weibring, Petter, additional, Apel, Eric C., additional, Hornbrook, Rebecca S., additional, Brown, Steven S., additional, Womack, Caroline C., additional, Robinson, Michael A., additional, Washenfelder, Rebecca A., additional, Veres, Patrick R., additional, and Neuman, J. Andrew, additional
- Published
- 2021
- Full Text
- View/download PDF
37. Ozone chemistry in western U.S. wildfire plumes
- Author
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Xu, Lu, primary, Crounse, John D., additional, Vasquez, Krystal T., additional, Allen, Hannah, additional, Wennberg, Paul O., additional, Bourgeois, Ilann, additional, Brown, Steven S., additional, Campuzano-Jost, Pedro, additional, Coggon, Matthew M., additional, Crawford, James H., additional, DiGangi, Joshua P., additional, Diskin, Glenn S., additional, Fried, Alan, additional, Gargulinski, Emily M., additional, Gilman, Jessica B., additional, Gkatzelis, Georgios I., additional, Guo, Hongyu, additional, Hair, Johnathan W., additional, Hall, Samuel R., additional, Halliday, Hannah A., additional, Hanisco, Thomas F., additional, Hannun, Reem A., additional, Holmes, Christopher D., additional, Huey, L. Gregory, additional, Jimenez, Jose L., additional, Lamplugh, Aaron, additional, Lee, Young Ro, additional, Liao, Jin, additional, Lindaas, Jakob, additional, Neuman, J. Andrew, additional, Nowak, John B., additional, Peischl, Jeff, additional, Peterson, David A., additional, Piel, Felix, additional, Richter, Dirk, additional, Rickly, Pamela S., additional, Robinson, Michael A., additional, Rollins, Andrew W., additional, Ryerson, Thomas B., additional, Sekimoto, Kanako, additional, Selimovic, Vanessa, additional, Shingler, Taylor, additional, Soja, Amber J., additional, St. Clair, Jason M., additional, Tanner, David J., additional, Ullmann, Kirk, additional, Veres, Patrick R., additional, Walega, James, additional, Warneke, Carsten, additional, Washenfelder, Rebecca A., additional, Weibring, Petter, additional, Wisthaler, Armin, additional, Wolfe, Glenn M., additional, Womack, Caroline C., additional, and Yokelson, Robert J., additional
- Published
- 2021
- Full Text
- View/download PDF
38. Photochemical Evolution of the 2013 California Rim Fire: Synergistic Impacts of Reactive Hydrocarbons and Enhanced Oxidants
- Author
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Wolfe, Glenn M., primary, Hanisco, Thomas F., additional, Arkinson, Heather L., additional, Blake, Donald R., additional, Wisthaler, Armin, additional, Mikoviny, Tomas, additional, Ryerson, Thomas B., additional, Pollack, Ilana, additional, Peischl, Jeff, additional, Wennberg, Paul O., additional, Crounse, John D., additional, St. Clair, Jason M., additional, Teng, Alex, additional, Huey, L. Gregory, additional, Liu, Xiaoxi, additional, Fried, Alan, additional, Weibring, Petter, additional, Richter, Dirk, additional, Walega, James, additional, Hall, Samuel R., additional, Ullmann, Kirk, additional, Jimenez, Jose L., additional, Campuzano-Jost, Pedro, additional, Bui, T. Paul, additional, Diskin, Glenn, additional, Podolske, James R., additional, Sachse, Glen, additional, and Cohen, Ronald C., additional
- Published
- 2021
- Full Text
- View/download PDF
39. Supplementary material to "Photochemical Evolution of the 2013 California Rim Fire: Synergistic Impacts of Reactive Hydrocarbons and Enhanced Oxidants"
- Author
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Wolfe, Glenn M., primary, Hanisco, Thomas F., additional, Arkinson, Heather L., additional, Blake, Donald R., additional, Wisthaler, Armin, additional, Mikoviny, Tomas, additional, Ryerson, Thomas B., additional, Pollack, Ilana, additional, Peischl, Jeff, additional, Wennberg, Paul O., additional, Crounse, John D., additional, St. Clair, Jason M., additional, Teng, Alex, additional, Huey, L. Gregory, additional, Liu, Xiaoxi, additional, Fried, Alan, additional, Weibring, Petter, additional, Richter, Dirk, additional, Walega, James, additional, Hall, Samuel R., additional, Ullmann, Kirk, additional, Jimenez, Jose L., additional, Campuzano-Jost, Pedro, additional, Bui, T. Paul, additional, Diskin, Glenn, additional, Podolske, James R., additional, Sachse, Glen, additional, and Cohen, Ronald C., additional
- Published
- 2021
- Full Text
- View/download PDF
40. The role of snow in controlling halogen chemistry and boundary layer oxidation during Arctic spring: A 1D modelling case study
- Author
-
Ahmed, Shaddy, primary, Thomas, Jennie L, additional, Tuite, Kathleen, additional, Stutz, Jochen, additional, Flocke, Frank, additional, Orlando, John, additional, Hornbrook, Rebecca S., additional, Apel, Eric C, additional, Emmons, Louisa K., additional, Helmig, Detlev, additional, Boylan, Patrick, additional, Huey, L. Gregory, additional, Hall, Samuel R, additional, Ullmann, Kirk, additional, Cantrell, Christopher A., additional, and Fried, Alan, additional
- Published
- 2021
- Full Text
- View/download PDF
41. Constraining emissions of volatile organic compounds from western US wildfires with WE-CAN and FIREX-AQ airborne observations.
- Author
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Jin, Lixu, Permar, Wade, Selimovic, Vanessa, Ketcherside, Damien, Yokelson, Robert J., Hornbrook, Rebecca S., Apel, Eric C., Ku, I-Ting, Collett Jr., Jeffrey L., Sullivan, Amy P., Jaffe, Daniel A., Pierce, Jeffrey R., Fried, Alan, Coggon, Matthew M., Gkatzelis, Georgios I., Warneke, Carsten, Fischer, Emily V., and Hu, Lu
- Subjects
BIOMASS burning ,VOLATILE organic compounds ,CHEMICAL transportation ,WILDFIRES ,DRY matter content of plants - Abstract
The impact of biomass burning (BB) on the atmospheric burden of volatile organic compounds (VOCs) is highly uncertain. Here we apply the GEOS-Chem chemical transport model (CTM) to constrain BB emissions in the western US at ~25 km resolution. Across three BB emission inventories widely used in CTMs, the total of 14 modeled BB VOC emissions in the western US agree with each other within 30–40 %. However, emissions for individual VOC differ by up to a factor of 5 (i.e. , lumped ≥ C
4 alkanes), driven by the regionally averaged emission ratios (ERs) among inventories. We further evaluate GEOS-Chem simulations with aircraft observations made during WE-CAN (Western Wildfire Experiment for Cloud Chemistry, Aerosol Absorption, and Nitrogen) and FIREX-AQ (Fire Influence on Regional to Global Environments and Air Quality) field campaigns. Despite being driven by different global BB inventories or applying various injection height assumptions, GEOS-Chem simulations underpredict observed vertical profiles by a factor of 3–7. The model shows small-to-no bias for most species in low/no smoke conditions. We thus attribute the negative model biases mostly to underestimated BB emissions in these inventories. Tripling BB emissions in the model reproduces observed vertical profiles for primary compounds, i.e., CO, propane, benzene, and toluene. However, it shows no-to-less significant improvements for oxygenated VOCs, particularly formaldehyde, formic acid, acetic acid, and lumped ≥ C3 aldehydes, suggesting the model is missing secondary sources of these compounds in BB-impacted environments. The underestimation of primary BB emissions in inventories is likely attributable to underpredicted amounts of effective dry matter burned, rather than errors in fire detection, injection height, or ERs. We cannot rule out potential sub-grid uncertainties (i.e. , not being able to fully resolve fire plumes) in the nested GEOS-Chem which could explain the model negative bias partially, though the back-of-the-envelope calculation and evaluation using longer-term ground measurements help increase the argument of the dry matter burned underestimation. The ERs of the 14 BB VOCs implemented in GEOS-Chem account for about half of the total 161 measured VOCs (~75 versus 150 ppb ppm-1 ). This reveals a significant amount of missing reactive organic carbon in widely-used BB emission inventories. Considering both uncertainties in effective dry matter burned and unmodeled VOCs, we infer that BB contributed up to 10 % in 2019 and 45 % in 2018 (240 and 2040 GgC) of the total VOC primary emission flux in the western US during these two fire seasons, compared to only 1–10 % in the standard GEOS-Chem. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
42. Characterization of Errors in Satellite-based HCHO / NO2 Tropospheric Column Ratios with Respect to Chemistry, Column to PBL Translation, Spatial Representation, and Retrieval Uncertainties.
- Author
-
Souri, Amir H., Johnson, Matthew S., Wolfe, Glenn M., Crawford, James H., Fried, Alan, Wisthaler, Armin, Brune, William H., Blake, Donald R., Weinheimer, Andrew J., Verhoelst, Tijl, Compernolle, Steven, Pinardi, Gaia, Vigouroux, Corinne, Langerock, Bavo, Choi, Sungyeon, Lamsal, Lok, Lei Zhu, Shuai Sun, Cohen, Ronald C., and Kyung-Eun Min
- Abstract
The availability of formaldehyde (HCHO) (a proxy for volatile organic compound reactivity) and nitrogen dioxide (NO
2 ) (a proxy for nitrogen oxides) tropospheric columns from Ultraviolet-Visible (UV-Vis) satellites has motivated many to use their ratios to gain some insights into the near-surface ozone sensitivity. Strong emphasis has been placed on the challenges that come with transforming what is being observed in the tropospheric column to what is actually in the planetary boundary layer (PBL) and near to the surface; however, little attention has been paid to other sources of error such as chemistry, spatial representation, and retrieval uncertainties. Here we leverage a wide spectrum of tools and data to carefully quantify those errors. Concerning the chemistry error, a well-characterized box model constrained by more than 500 hours of aircraft data from NASA’s air quality campaigns is used to simulate the ratio of the chemical loss of HO2 +RO2 (LROx) to the chemical loss of NOx (LNOx). Subsequently, we challenge the predictive power of HCHO / NO2 ratios (FNRs), which are commonly applied in current research, at detecting the underlying ozone regimes by comparing them to LROx / LNOx. FNRs show a strongly linear (R²=0.94) relationship to LROx / LNOx in the log-log scale. Following the baseline (i.e., ln(LROx / LNOx) = -1.0±0.2) with the model and mechanism (CB06, r2) used for segregating NOx -sensitive from VOC-sensitive regimes, we observe a broad range of FNR thresholds ranging from 1 to 4. The transitioning ratios strictly follow a Gaussian distribution with a mean and standard deviation of 1.8 and 0.4, respectively. This implies that FNR has an inherent 20 % standard error (1-sigma) resulting from not being able to fully describe the ROx-HOx cycle. We calculate high ozone production rates (PO3 ) dominated by large HCHO×NO2 concentration levels, a new proxy for the abundance of ozone precursors. The relationship between PO3 and HCHO×NO2 becomes more pronounced when moving towards NOx -sensitive regions due to non-linear chemistry; our results indicate that there is fruitful information in the HCHO×NO2 metric that has not been utilized in ozone studies. The vast amount of vertical information on HCHO and NO2 concentration from the air quality campaigns enables us to parameterize the vertical shapes of FNRs using a second-order rational function permitting an analytical solution for an altitude adjustment factor to partition the tropospheric columns to the PBL region. We propose a mathematical solution to the spatial representation error based on modeling isotropic semivariograms. With respect to a high-resolution sensor like TROPOspheric Monitoring Instrument (TROPOMI) (>5.5×3.5 km²), Ozone Monitoring Instrument (OMI) loses 12 % of spatial information at its native resolution. A pixel with a grid size of 216 km² fails at capturing ~65 % of the spatial information in FNRs at a 50 km length scale comparable to the size of a large urban center (e.g., Los Angeles). We ultimately leverage a large suite of in-situ and ground-based remote sensing measurements to draw the error distributions of daily TROPOMI and OMI tropospheric NO2 and HCHO columns. At 68 % confidence interval (1 sigma) errors pertaining to daily TROPOMI observations, either HCHO or tropospheric NO2 columns should be above 1.2–1.5×1016 molec.cm-2 to attain 20–30 % standard error in the ratio. This level of error is almost non-achievable with OMI given its large error in HCHO. The satellite column retrieval error is the largest contributor to the total error (40–90 %) in the FNRs. Due to a stronger signal in cities, the total relative error (<50 %) tends to be mild, whereas areas with low vegetation and anthropogenic sources (e.g., Rocky Mountains) are markedly uncertain (>100 %). Our study suggests that continuing development in the retrieval algorithm and sensor design and calibration is essential to be able to advance the application of FNRs beyond a qualitative metric. The availability of formaldehyde (HCHO) (a proxy for volatile organic compound reactivity) and nitrogen dioxide (NO2 ) (a proxy for nitrogen oxides) tropospheric columns from Ultraviolet-Visible (UV-Vis) satellites has motivated many to use their ratios to gain some insights into the near-surface ozone sensitivity. Strong emphasis has been placed on the challenges that come with transforming what is being observed in the tropospheric column to what is actually in the planetary boundary layer (PBL) and near to the surface; however, little attention has been paid to other sources of error such as chemistry, spatial representation, and retrieval uncertainties. Here we leverage a wide spectrum of tools and data to carefully quantify those errors. Concerning the chemistry error, a well-characterized box model constrained by more than 500 hours of aircraft data from NASA’s air quality campaigns is used to simulate the ratio of the chemical loss of HO2 +RO2 (LROx) to the chemical loss of NOx (LNOx). Subsequently, we challenge the predictive power of HCHO / NO2 ratios (FNRs), which are commonly applied in current research, at detecting the underlying ozone regimes by comparing them to LROx / LNOx. FNRs show a strongly linear (R²=0.94) relationship to LROx / LNOx in the log-log scale. Following the baseline (i.e., ln(LROx / LNOx) = -1.0±0.2) with the model and mechanism (CB06, r2) used for segregating NOx -sensitive from VOC-sensitive regimes, we observe a broad range of FNR thresholds ranging from 1 to 4. The transitioning ratios strictly follow a Gaussian distribution with a mean and standard deviation of 1.8 and 0.4, respectively. This implies that FNR has an inherent 20 % standard error (1-sigma) resulting from not being able to fully describe the ROx-HOx cycle. We calculate high ozone production rates (PO3 ) dominated by large HCHO×NO2 concentration levels, a new proxy for the abundance of ozone precursors. The relationship between PO3 and HCHO×NO2 becomes more pronounced when moving towards NOx -sensitive regions due to non-linear chemistry; our results indicate that there is fruitful information in the HCHO×NO2 metric that has not been utilized in ozone studies. The vast amount of vertical information on HCHO and NO2 concentration from the air quality campaigns enables us to parameterize the vertical shapes of FNRs using a second-order rational function permitting an analytical solution for an altitude adjustment factor to partition the tropospheric columns to the PBL region. We propose a mathematical solution to the spatial representation error based on modeling isotropic semivariograms. With respect to a high-resolution sensor like TROPOspheric Monitoring Instrument (TROPOMI) (>5.5×3.5 km²), Ozone Monitoring Instrument (OMI) loses 12 % of spatial information at its native resolution. A pixel with a grid size of 216 km² fails at capturing ~65 % of the spatial information in FNRs at a 50 km length scale comparable to the size of a large urban center (e.g., Los Angeles). We ultimately leverage a large suite of in-situ and ground-based remote sensing measurements to draw the error distributions of daily TROPOMI and OMI tropospheric NO2 and HCHO columns. At 68 % confidence interval (1 sigma) errors pertaining to daily TROPOMI observations, either HCHO or tropospheric NO2 columns should be above 1.2–1.5×1016 molec.cm-2 to attain 20–30 % standard error in the ratio. This level of error is almost non-achievable with OMI given its large error in HCHO. The satellite column retrieval error is the largest contributor to the total error (40–90 %) in the FNRs. Due to a stronger signal in cities, the total relative error (<50 %) tends to be mild, whereas areas with low vegetation and anthropogenic sources (e.g., Rocky Mountains) are markedly uncertain (>100 %). Our study suggests that continuing development in the retrieval algorithm and sensor design and calibration is essential to be able to advance the application of FNRs beyond a qualitative metric. [ABSTRACT FROM AUTHOR]- Published
- 2022
- Full Text
- View/download PDF
43. Composition and Reactivity of Volatile Organic Compounds in the South Coast Air Basin and San Joaquin Valley of California.
- Author
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Shang Liu, Barletta, Barbara, Hornbrook, Rebecca S., Fried, Alan, Peischl, Jeff, Meinardi, Simone, Coggon, Matthew, Lamplugh, Aaron, Gilman, Jessica B., Gkatzelis, Georgios I., Warneke, Carsten, Apel, Eric C., Hills, Alan J., Bourgeois, Ilann, Walega, James, Weibring, Petter, Richter, Dirk, Toshihiro Kuwayama, FitzGibbon, Michael, and Blake, Donald
- Abstract
Comprehensive aircraft measurements of volatile organic compounds (VOCs) covering the South Coast Air Basin (SoCAB) and San Joaquin Valley (SJV) of California were obtained in the summer of 2019. Combined with the CO, CH4, and NOx data, the total measured gas-phase hydroxyl radical reactivity (OHRTOTAL) was quantified. VOCs accounted for ~60%-70% of the OHRTOTAL in both basins. In particular, oxygenated VOCs (OVOCs) contributed > 60% of the OHR of total VOCs (OHRVOC) as well as the total observed VOC mixing ratio. Primary biogenic VOCs (BVOCs) represented a minor fraction (< 2%) of the total VOC mixing ratio but accounted for 21% and 6% of the OHRVOC in the SoCAB and SJV, respectively. Furthermore, the contribution of BVOCs to the OHRVOC increased with increasing OHRVOC in the SoCAB, suggesting that BVOCs was important ozone precursors during high ozone episodes. Spatially, the trace gases were heterogeneously distributed in the SoCAB with their mixing ratios and OHR significantly greater over the inland regions than the coast, while their levels were more evenly distributed in the SJV. The results highlight that a better grasp of the emission rates and sources of OVOCs and BVOCs is essential for a predictive understanding of the ozone abundance and distribution in California. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
44. Photochemical Evolution of the 2013 California Rim Fire: Synergistic Impacts of Reactive Hydrocarbons and Enhanced Oxidants.
- Author
-
Wolfe, Glenn M., Hanisco, Thomas F., Arkinson, Heather L., Blake, Donald R., Wisthaler, Armin, Mikoviny, Tomas, Ryerson, Thomas B., Pollack, Ilana, Peischl, Jeff, Wennberg, Paul O., Crounse, John D., St. Clair, Jason M., Teng, Alex, Huey, L. Gregory, Xiaoxi Liu, Fried, Alan, Weibring, Petter, Richter, Dirk, Walega, James, and Hall, Samuel R.
- Abstract
Large wildfires markedly alter regional atmospheric composition, but chemical complexity challenges model predictions of downwind impacts. Here, we elucidate key facets of gas-phase photochemistry and assess novel chemical processes via a case study of the 2013 California Rim Fire plume. Airborne in situ observations, acquired during the NASA Studies of Emissions, Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC4RS) mission, illustrate the evolution of volatile organic compounds (VOC), oxidants, and reactive nitrogen over 12 hours of atmospheric aging. Measurements show rapid formation of ozone and peroxyacyl nitrates (PNs), sustained peroxide production, and prolonged enhancements in oxygenated VOC and nitrogen oxides (NO[sub x]). Measurements and Lagrangian trajectories constrain a 0-D puff model that approximates plume photochemical history and provides a framework for evaluating key processes. Simulations examine the effects of 1) previously -unmeasured reactive VOC identified in recent laboratory studies, and 2) emissions and secondary production of nitrous acid (HONO). Inclusion of estimated unmeasured VOC leads to a 250% increase in OH reactivity and a 70% increase in radical production via oxygenated VOC photolysis. HONO amplifies radical cycling and serves as a downwind NO[sub x] source, although two different HONO production mechanisms (particulate nitrate photolysis and heterogeneous NO[sub 2] conversion) exhibit markedly different effects on ozone, NO[sub x], and PNs. Analysis of radical initiation rates suggests that oxygenated VOC photolysis is a major radical source, exceeding HONO photolysis when averaged over the first 2 hours of aging. Ozone production chemistry transitions from VOC-sensitive to NO[sub x]-sensitive within the first hour of plume aging, with both peroxide and organic nitrate formation contributing significantly to radical termination. To simulate smoke plume chemistry accurately, models should simultaneously account for the full reactive VOC pool and all relevant oxidant sources. [ABSTRACT FROM AUTHOR]
- Published
- 2021
- Full Text
- View/download PDF
45. Ozone chemistry in western U.S. wildfire plumes.
- Author
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Lu Xu, Crounse, John D., Vasquez, Krystal T., Allen, Hannah, Wennberg, Paul O., Bourgeois, Ilann, Brown, Steven S., Campuzano-Jost, Pedro, Coggon, Matthew M., Crawford, James H., DiGangi, Joshua P., Diskin, Glenn S., Fried, Alan, Gargulinski, Emily M., Gilman, Jessica B., Gkatzelis, Georgios I., Hongyu Guo, Hair, Johnathan W., Hall, Samuel R., and Halliday, Hannah A.
- Subjects
- *
TROPOSPHERIC ozone , *CARBONACEOUS aerosols , *OZONE , *CHEMICAL ionization mass spectrometry , *WILDFIRES , *APPLIED sciences , *ATMOSPHERIC chemistry - Abstract
The article presents a study that investigates the highly variable ozone (O3) chemistry in wildfire plumes. It mentions that exploit the in situ chemical characterization of western wildfires during the Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) flight campaign. It discusses that O3 formation limited by the abundance of nitrogen oxides (NOx).
- Published
- 2021
- Full Text
- View/download PDF
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