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569 results on '"Bönisch, H."'

1. Age of Stratospheric Air: Progress on Processes, Observations, and Long‐Term Trends.

Author

Garny, H., Ploeger, F., Abalos, M., Bönisch, H., Castillo, A. E., von Clarmann, T., Diallo, M., Engel, A., Laube, J. C., Linz, M., Neu, J. L., Podglajen, A., Ray, E., Rivoire, L., Saunders, L. N., Stiller, G., Voet, F., Wagenhäuser, T., and Walker, K. A.

Abstract

Age of stratospheric air is a well established metric for the stratospheric transport circulation. Rooted in a robust theoretical framework, this approach offers the benefit of being deducible from observations of trace gases. Given potential climate‐induced changes, observational constraints on stratospheric circulation are crucial. In the past two decades, scientific progress has been made in three main areas: (a) Enhanced process understanding and the development of process diagnostics led to better quantification of individual transport processes from observations and to a better understanding of model deficits. (b) The global age of air climatology is now well constrained by observations thanks to improved quality and quantity of data, including global satellite data, and through improved and consistent age calculation methods. (c) It is well established and understood that global models predict a decrease in age, that is, an accelerating stratospheric circulation, in response to forcing by greenhouse gases and ozone depleting substances. Observational records now confirm long‐term forced trends in mean age in the lower stratosphere. However, in the mid‐stratosphere, uncertainties in observational records are too large to confirm or disprove the model predictions. Continuous monitoring of stratospheric trace gases and further improved methods to derive age from those tracers will be crucial to better constrain variability and long‐term trends from observations. Future work on mean age as a metric for stratospheric transport will be important due to its potential to enhance the understanding of stratospheric composition changes, address climate model biases, and assess the impacts of proposed climate geoengineering methods. Plain Language Summary: Transport strongly influences the composition of the stratosphere, the layer at around 10–50 km altitude. Air masses are transported upward into the stratosphere in the tropics, and get distributed globally by a hemisphere‐wide overturning circulation. Stratospheric age of air is a measure of the transport times along this circulation. This metric is a crucial measure of the circulation strength, deducible from observations of certain stratospheric gases. Over the past two decades, scientific progress has been made in three main areas. First, we now understand better which processes influence transport times. Second, we have good knowledge on the global average distribution of age of air, thanks to more observational data and improved methods to deduce this metric. Third, a large focus has been on climate‐change related trends in age of air. While it is well established and understood that global models predict an accelerating stratospheric circulation, the related decrease in age of air can only be confirmed observationally in the lower stratosphere. Continuous monitoring of stratospheric trace gases will be crucial to constrain circulation trends throughout the stratosphere. This is essential for understanding climate change effects, improving climate models, and assessing potential climate intervention strategies. Key Points: Understanding of how individual processes impact stratospheric age of air has been improved through development of dedicated diagnosticsThe global age of air climatology is now well constrained by observations thanks to improved data records and age calculation methodsObserved age trends confirm lower stratospheric model predictions but are too uncertain to confirm or dismiss middle stratospheric trends [ABSTRACT FROM AUTHOR]

Published
2024
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3. The Norepinephrine Transporter in Physiology and Disease

Author

Bönisch, H., Brüss, M., Starke, K., editor, Born, G. V. R., editor, Duckles, S. P., editor, Eichelbaum, M., editor, Ganten, D., editor, Hofmann, F., editor, Rosenthal, W., editor, Rubanyi, G., editor, Sitte, Harald H., editor, and Freissmuth, Michael, editor

Published
2006
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9. Cloud-scale modelling of the impact of deep convection on the fate of oceanic bromoform in the troposphere:a case study over the west coast of Borneo

Author

Hamer, P. D., Marécal, V., Hossaini, R., Pirre, M., Krysztofiak, G., Ziska, F., Engel, A., Sala, S., Keber, T., Bönisch, H., Atlas, E., Krüger, K., Chipperfield, M., Catoire, V., Samah, A. A., Dorf, M., Siew Moi, P., Schlager, H., Pfeilsticker, K., Hamer, P. D., Marécal, V., Hossaini, R., Pirre, M., Krysztofiak, G., Ziska, F., Engel, A., Sala, S., Keber, T., Bönisch, H., Atlas, E., Krüger, K., Chipperfield, M., Catoire, V., Samah, A. A., Dorf, M., Siew Moi, P., Schlager, H., and Pfeilsticker, K.

Abstract

This paper presents a modelling study on the fate of CHBr3 and its product gases in the troposphere within the context of tropical deep convection. A cloud-scale case study was conducted along the west coast of Borneo, where several deep convective systems were triggered on the afternoon and early evening of 19 November 2011. These systems were sampled by the Falcon aircraft during the field campaign of the SHIVA project and analysed using a simulation with the cloud-resolving meteorological model C-CATT-BRAMS at 2×2 km resolution that represents the emissions, transport by large-scale flow, convection, photochemistry, and washout of CHBr3 and its product gases (PGs). We find that simulated CHBr3 mixing ratios and the observed values in the boundary layer and the outflow of the convective systems agree. However, the model underestimates the background CHBr3 mixing ratios in the upper troposphere, which suggests a missing source at the regional scale. An analysis of the simulated chemical speciation of bromine within and around each simulated convective system during the mature convective stage reveals that >85 % of the bromine derived from CHBr3 and its PGs is transported vertically to the point of convective detrainment in the form of CHBr3 and that the remaining small fraction is in the form of organic PGs, principally insoluble brominated carbonyls produced from the photo-oxidation of CHBr3. The model simulates that within the boundary layer and free troposphere, the inorganic PGs are only present in soluble forms, i.e. HBr, HOBr, and BrONO2, and, consequently, within the convective clouds, the inorganic PGs are almost entirely removed by wet scavenging. We find that HBr is the most abundant PG in background lower-tropospheric air and that this prevalence of HBr is a result of the relatively low background tropospheric ozone levels at the regional scale. Contrary to a previous study in a different environment, for the conditions in the simulation, the insoluble B

Published
2021

13. Bromine from short-lived source gases in the extratropical northern hemispheric upper troposphere and lower stratosphere (UTLS)

Author

Keber, T., Bönisch, H., Hartick, C., Hauck, M., Lefrancois, F., Obersteiner, F., Ringsdorf, A., Schohl, N., Schuck, T., Hossaini, R., Graf, P., Jöckel, P., Engel, A., Keber, T., Bönisch, H., Hartick, C., Hauck, M., Lefrancois, F., Obersteiner, F., Ringsdorf, A., Schohl, N., Schuck, T., Hossaini, R., Graf, P., Jöckel, P., and Engel, A.

Abstract

We present novel measurements of five short-lived brominated source gases (CH2Br2, CHBr3, CH2ClBr, CHCl2Br and CHClBr2). These rather short-lived gases are an important source of bromine to the stratosphere, where they can lead to depletion of ozone. The measurements have been obtained using an in situ gas chromatography and mass spectrometry (GC–MS) system on board the High Altitude and Long Range Research Aircraft (HALO). The instrument is extremely sensitive due to the use of chemical ionization, allowing detection limits in the lower parts per quadrillion (ppq, 10−15) range. Data from three campaigns using HALO are presented, where the upper troposphere and lower stratosphere (UTLS) of the northern hemispheric mid-to-high latitudes were sampled during winter and during late summer to early fall. We show that an observed decrease with altitude in the stratosphere is consistent with the relative lifetimes of the different compounds. Distributions of the five source gases and total organic bromine just below the tropopause show an increase in mixing ratio with latitude, in particular during polar winter. This increase in mixing ratio is explained by increasing lifetimes at higher latitudes during winter. As the mixing ratios at the extratropical tropopause are generally higher than those derived for the tropical tropopause, extratropical troposphere-to-stratosphere transport will result in elevated levels of organic bromine in comparison to air transported over the tropical tropopause. The observations are compared to model estimates using different emission scenarios. A scenario with emissions mainly confined to low latitudes cannot reproduce the observed latitudinal distributions and will tend to overestimate organic bromine input through the tropical tropopause from CH2Br2 and CHBr3. Consequently, the scenario also overestimates the amount of brominated organic gases in the stratosphere. The two scenarios with the highest overall emissions of CH2Br2 tend to over

Published
2020

29. Abstracts Second Congress of the European Society for Clinical Neuropharmacology: Würzburg, November 9–11, 1995

Author

Agid, Y., Arendt, T., Gärtner, U., Holzer, M., Fruth, P., Brückner, M. K., Arzberger, T., Weindl, A., Baas, H., Demisch, L., Harder, S., Bürklin, F., Fischer, P. A., Bagli, M., Rao, M. L., Sobanski, T., Laux, G., Barbier, P., Fumagalli, F., Donati, E., Maggio, R., Racagni, G., Corsini, G. U., Riva, M., Berger, J., Löschl, B., Bernheimer, H., Lugowska, A., Tylki-Szymanska, A., Gieselmann, V., Molzer, B., Faé, I., Bernocchi, G., Scherini, E., Necchi, D., Bigl, M., Bleyl, D., Bigl, V., Eschrich, K., Block, F., Schwarz, M., Blum-Degen, D., Müller, Th., Kuhn, W., Gerlach, M., Przuntek, H., Riederer, R., Bonuccelli, U., Ceravolo, R., Nuti, A., D'Avino, C., Placidi, G., Perugi, G., Cassano, G. B., Del Dotto, P., Piccini, P., Colzi, A., Muratorio, A., Braak, H., Braak, E., Yilmazer, D. M., de Vos, R. A. I., Jansen, E. N. H., Bringmann, G., Clement, H. W., Grote, C., Rausch, F., Reichmann, H., Riederer, P., Sontag, K. -H., Wesemann, W., God, R., Feineis, D., Brückner, R., Protzen, J. -A., Fähr, S., Rausch, W. -D., Brunt, E. R. P., Pruim, J., Willemsen, A. J., van Weerden, T. W., Bryan-Lluka, L. J., Bönisch, H., Büttner, Th., Kühn, W., McMonagle, U., Calza, L., Pozza, M., Coraddu, F., Farci, G., Carlsson, A., Napolitano, A., Salvetti, S., Dell'Agnello, G., Renna, M., Conquet, F., Bashir, Z., Daniel, H., Ferraguti, F., Collingridge, G., Crépel, F., Coos Verhoef, J., Merkus, F. W. H. M., Junginger, H. E., Cruz-Sánchez, F. F., Kutschka, T., Beeg, M., Deuschle, M., Weber, B., Körner, A., Standhardt, H., Lammers, C. -H., Motzek-Noé, T., Heuser, I., Earl, C. D., Reum, T., Sautter, J., Xie, J. -X, Kupsch, A., Oertel, W. H., Morgenstern, R., Emilien, G. M., Maloteaux, J. M., Seghers, A., Charles, G., Erdmann, R., Högemann, D., Fichter, N., Lücking, C. H., Landwehrmeyer, G. B., Winter, T., Feuerstein, T. J., Fitzgeral, D., Anderson, M. C., Lawlor, B., Tipton, K. F., Frackowiak, R. S. J., Freo, U., Dam, M., Pizzolato, G., Merico, A., Ori, C., Sale, E., Battistin, L., Fritze, J., Froelich, L., Goetz, M., Gsell, W., Jellinger, K., Beckmann, H., Fünfgeld, E. W., Glinka, Y., Youdim, M. B. H., Götz, M. E., Breithaupt, W., Burger, R., Streifler, M., Simanyi, M., Müller, F., Danielczyk, W., Hirning, T., Sohlbach, M., Nafc, R., Sternadl, H., Winter, M., Nöth, U., Heim, C., Hartmann, J., Künig, G., Niedermeyer, B., Berger, W., Deckert, J., Abel, F., Heinsen, H., Senitz, D., Mayr, J., Ransmayr, G., Hartung, H. -P., Heils, A., Teufel, A., Petri, S., Seemann, M., Bengel, D., Degen, H. J., Lesch, K. P., Sontag, T., Heinen, F., Korinthenberg, R., Heiss, W. -D., Rüb, U., Gangus, B., Jungkunz, G., Bauer, M., Ulmar, G., Böcker, F., Schüler, M., Bethke, B., Lockemann, U., Hermans, E., Vanhoorde, P., Hesse, S., Hüll, M., Fiebich, B., Lieb, K., Strauss, S., Berger, M., Volk, B., Bauer, J., Iversen, L. L., Janetzky, B., Hauck, S., Jeanjean, A. P., Laterre, E. C., Bancher, C., Jost, W. H., Kalus, P., Kanner, B., Khrapova, E. V., Brusov, O. S., Knauber, J., Müller, W. E., Korczyn, A. D., Kornhuber, J., Parsons, C. G., Hartmann, S., Retz, W., Kamolz, S., Thome, J., Koutsilieri, E., Chen, T. -S., Kreutzberg, G. W., Krieglstein, J., Winkel, R., Danielcyk, S., Gerstner, A., Mattern, C., Häcker, R., Labunsky, D., Zhirnova, I., Komelkova, L., Popova, L., Avdiunina, I., Lakke, J. P. W. F., Lange, K. W., Steup, A., Tucha, O., Naumann, M., Lassmann, H., Leszek, J., Gasiorowski, K., Inglot, D., Lohse, M. J., Löschmann, P. -A., Eblen, F., Wüllner, U., Klockgether, T., Dichgans, J., Macrae, I. M., Mimmack, M. L., Emson, P., Norta, M., Borchert, H. -H., Medori, R., Chan, W. W., Heinemann, T., Melzacka, M., Kolasiewicz, W., Sieklucka, M., Jaros, T., Mesec, A., Šega, S., Kiauta, T., Moser, A., Vieregge, P., Siebecker, F., Münch, G., Schinzel, R., Michaelis, J., Cunningham, A., Da Prada, M., Borroni, E., Zürcher, G., Reiners, K., Neveu, P. J., Nitsch, R. M., Pavese, N., Lucetti, C., Rossi, G., Offen, D., Ziv, I., Stein, R., Barzilai, A., Hochman, A., Melamed, E., Ozawa, H., Hashimoto, E., Saito, T., Ymamoto, M., Takahata, N., Frölich, L., Paulus, W., Hermsteiner, E., Haug, B., Bandelow, B., Peckys, D., Gleichauf, O., Jackisch, R., Landwehrmeyer, B., Bloß, H. G., Plaschke, K., Müller, D., Hoyer, S., Avdyuna, L. A., Putzke, J., Spanagel, R., Tolle, T. R., Zieglgänsberger, W., Rabey, J. -M., Orlov, E., von Raison, F., Lehmann, K., Havemann-Reinecke, U., Butà, M., Federspiel, S., Maier, H., Abdel-mohsen, M., Abdel-moneim, M., Reynolds, G. P., Sardar, A. M., Eggett, C. J., Rosario, P., de la Morena, E., José Barro, M., Rossini, P. M., Roth, J., Růžička, E., Svobodová, I., Mečíř, P., Jech, R., Remeš, F., Kleinschroth, A., Schliebs, R., Roßner, S., Heider, M., Schubert, H., König, P., Schuttes, H., HaveIec, L., Schwartz, J. -C., Sendtner, M., Smith, A., Li, M., Griesbeck, O., Parsadanian, A., Holtmann, B., Carroll, P., Toyka, K. V., Thoenen, H., Sharkawy, A. A., Ibrahim, T. A., Pulkowski, U., Siesjö, B. K., Klessaschek, M., Sopper, S., Demuth, M., Dörries, R., Hemm, S., Stahl-Hennig, C., Brinkmann, R., ter Meulen, V., Sperk, G., Schwarzer, C., Stern, G., Storm, G., Strein, I., Struck, M., Stürenburg, H. J., Kunze, K., Svadovsky, A. I., Morgunov, K. V., Peresedov, V. V., Moshkin, A. V., Teherani, D. K., Baumer, A., Rösier, M., Rösler, M., Wiesbeck, G. A., Wodarz, N., Boning, J., Timerbaeva, S. L., Alekseeva, N. S., Toso, A., Barletta, D., Tuulik, V., Lossmann, E., Raja, A., Meister, A., Uitti, R. J., Rajput, A. H., Ahlskog, J. E., Offord, K. P., Schroeder, D. R., O'Brien, P. C., Vaglini, F., Fascetti, F., Pardini, C., Mancino, L., Velbinger, K., Hartmann, H., Eckert, A., Grüter, S., Behrens, S., Niemann, J., Guschelbauer, B., Lauk, M., Wissel, J., Poewe, W., Wurthman, C., Janzen, E. N. H., Goping, G., Adegemo, O. M., Gemma, A., Kuijpers, J., Pollard, H. B., Zielke, B., Ziemann, U., and Bruns, D.

Published
1995
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37. A refined method for calculating equivalent effective stratospheric chlorine

Author

Engel, A, Bönisch, H, Ostermöller, J, Chipperfield, MP, Dhomse, S, Jöckel, P, and Kaiser, Jan

Subjects
ozone depleting substances, ODS, EMAC, ozone, Earth sciences, Erdsystem-Modellierung, stratosphere, TOMCAT, ddc:550, stratospheric chlorine, ECHAM/MESSy Atmospheric Chemistry, EESC, Earth System Chemistry integrated Modelling (ESCiMo)
Abstract

Chlorine and bromine atoms lead to catalytic depletion of ozone in the stratosphere. Therefore the use and production of ozone-depleting substances (ODSs) containing chlorine and bromine is regulated by the Montreal Protocol to protect the ozone layer. Equivalent effective stratospheric chlorine (EESC) has been adopted as an appropriate metric to describe the combined effects of chlorine and bromine released from halocarbons on stratospheric ozone. Here we revisit the concept of calculating EESC. We derive a refined formulation of EESC based on an advanced concept of ODS propagation into the stratosphere and reactive halogen release. A new transit time distribution is introduced in which the age spectrum for an inert tracer is weighted with the release function for inorganic halogen from the source gases. This distribution is termed the "release time distribution". We show that a much better agreement with inorganic halogen loading from the chemistry transport model TOMCAT is achieved compared with using the current formulation. The refined formulation shows EESC levels in the year 1980 for the mid-latitude lower stratosphere, which are significantly lower than previously calculated. The year 1980 is commonly used as a benchmark to which EESC must return in order to reach significant progress towards halogen and ozone recovery. Assuming that - under otherwise unchanged conditions - the EESC value must return to the same level in order for ozone to fully recover, we show that it will take more than 10 years longer than estimated in this region of the stratosphere with the current method for calculation of EESC. We also present a range of sensitivity studies to investigate the effect of changes and uncertainties in the fractional release factors and in the assumptions on the shape of the release time distributions. We further discuss the value of EESC as a proxy for future evolution of inorganic halogen loading under changing atmospheric dynamics using simulations from the EMAC model. We show that while the expected changes in stratospheric transport lead to significant differences between EESC and modelled inorganic halogen loading at constant mean age, EESC is a reasonable proxy for modelled inorganic halogen on a constant pressure level.

Published
2018
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47. Depletion of ozone and reservoir species of chlorine and nitrogen oxide in the lower Antarctic polar vortex measured from aircraft

Author

Jurkat, T., primary, Voigt, C., additional, Kaufmann, S., additional, Grooß, J.‐U., additional, Ziereis, H., additional, Dörnbrack, A., additional, Hoor, P., additional, Bozem, H., additional, Engel, A., additional, Bönisch, H., additional, Keber, T., additional, Hüneke, T., additional, Pfeilsticker, K., additional, Zahn, A., additional, Walker, K. A., additional, Boone, C. D., additional, Bernath, P. F., additional, and Schlager, H., additional

Published
2017
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48. A multi-model intercomparison of halogenated very short-lived substances (TransCom-VSLS):linking oceanic emissions and tropospheric transport for a reconciled estimate of the stratospheric source gas injection of bromine

Author

Hossaini, R., Patra, P. K., Leeson, A. A., Krysztofiak, G., Abraham, N. L., Archibald, A. T., Aschmann, J., Atlas, E. L., Belikov, D. A., Bönisch, H., Carpenter, L. J., Dhomse, S., Dorf, M., Engel, A., Feng, W., Fuhlbrügge, S., Griffiths, P. T., Harris, N. R. P., Hommel, R., Keber, T., Krüger, K., Lennartz, S. T., Maksyutov, S., Mantle, H., Mills, G. P., Montzka, S. A., Moore, F., Navarro, M. A., Oram, D. E., Pfeilsticker, K., Pyle, J. A., Quack, B., Saikawa, E., Saiz-Lopez, A., Sala, S., Sinnhuber, B.-M., Taguchi, S., Tegtmeier, S., Lidster, R. T., Ziska, F., Hossaini, R., Patra, P. K., Leeson, A. A., Krysztofiak, G., Abraham, N. L., Archibald, A. T., Aschmann, J., Atlas, E. L., Belikov, D. A., Bönisch, H., Carpenter, L. J., Dhomse, S., Dorf, M., Engel, A., Feng, W., Fuhlbrügge, S., Griffiths, P. T., Harris, N. R. P., Hommel, R., Keber, T., Krüger, K., Lennartz, S. T., Maksyutov, S., Mantle, H., Mills, G. P., Montzka, S. A., Moore, F., Navarro, M. A., Oram, D. E., Pfeilsticker, K., Pyle, J. A., Quack, B., Saikawa, E., Saiz-Lopez, A., Sala, S., Sinnhuber, B.-M., Taguchi, S., Tegtmeier, S., Lidster, R. T., and Ziska, F.

Abstract

The first concerted multi-model intercomparison of halogenated very short-lived substances (VSLS) has been performed, within the framework of the ongoing Atmospheric Tracer Transport Model Intercomparison Project (TransCom). Eleven global models or model variants participated (nine chemical transport models and two chemistry–climate models) by simulating the major natural bromine VSLS, bromoform (CHBr3) and dibromomethane (CH2Br2), over a 20-year period (1993–2012). Except for three model simulations, all others were driven offline by (or nudged to) reanalysed meteorology. The overarching goal of TransCom-VSLS was to provide a reconciled model estimate of the stratospheric source gas injection (SGI) of bromine from these gases, to constrain the current measurement-derived range, and to investigate inter-model differences due to emissions and transport processes. Models ran with standardised idealised chemistry, to isolate differences due to transport, and we investigated the sensitivity of results to a range of VSLS emission inventories. Models were tested in their ability to reproduce the observed seasonal and spatial distribution of VSLS at the surface, using measurements from NOAA's long-term global monitoring network, and in the tropical troposphere, using recent aircraft measurements – including high-altitude observations from the NASA Global Hawk platform. The models generally capture the observed seasonal cycle of surface CHBr3 and CH2Br2 well, with a strong model–measurement correlation (r ≥ 0.7) at most sites. In a given model, the absolute model–measurement agreement at the surface is highly sensitive to the choice of emissions. Large inter-model differences are apparent when using the same emission inventory, highlighting the challenges faced in evaluating such inventories at the global scale. Across the ensemble, most consistency is found within the tropics where most of the models (8 out of 11) achieve best agreement to surface CHBr3 observations usin

Published
2016

49. A multi-model intercomparison of halogenated very short-lived substances (TransCom-VSLS): linking oceanic emissions and tropospheric transport for a reconciled estimate of the stratospheric source gas injection of bromine

Author

Hossaini, R., Patra, P. K., Leeson, A. A., Krysztofiak, G., Abraham, N. L., Andrews, S. J., Archibald, A. T., Aschmann, J., Atlas, E. L., Belikov, D. A., Bönisch, H., Butler, R., Carpenter, L. J., Dhomse, S., Dorf, M., Engel, A., Feng, L., Feng, W., Fuhlbrügge, Steffen, Griffiths, P. T., Harris, N. R. P., Hommel, R., Keber, T., Krüger, Kirstin, Lennartz, Sinnika T., Maksyutov, S., Mantle, H., Mills, G. P., Miller, B., Montzka, S. A., Moore, F., Navarro, M. A., Oram, D. E., Palmer, P. I., Pfeilsticker, K., Pyle, J. A., Quack, Birgit, Robinson, A. D., Saikawa, E., Saiz-Lopez, A., Sala, S., Sinnhuber, B.-M., Taguchi, S., Tegtmeier, Susann, Lidster, R. T., Wilson, C., Ziska, Franziska, Hossaini, R., Patra, P. K., Leeson, A. A., Krysztofiak, G., Abraham, N. L., Andrews, S. J., Archibald, A. T., Aschmann, J., Atlas, E. L., Belikov, D. A., Bönisch, H., Butler, R., Carpenter, L. J., Dhomse, S., Dorf, M., Engel, A., Feng, L., Feng, W., Fuhlbrügge, Steffen, Griffiths, P. T., Harris, N. R. P., Hommel, R., Keber, T., Krüger, Kirstin, Lennartz, Sinnika T., Maksyutov, S., Mantle, H., Mills, G. P., Miller, B., Montzka, S. A., Moore, F., Navarro, M. A., Oram, D. E., Palmer, P. I., Pfeilsticker, K., Pyle, J. A., Quack, Birgit, Robinson, A. D., Saikawa, E., Saiz-Lopez, A., Sala, S., Sinnhuber, B.-M., Taguchi, S., Tegtmeier, Susann, Lidster, R. T., Wilson, C., and Ziska, Franziska

Abstract

The first concerted multi-model intercomparison of halogenated very short-lived substances (VSLS) has been performed, within the framework of the ongoing Atmospheric Tracer Transport Model Intercomparison Project (TransCom). Eleven global models or model variants participated, simulating the major natural bromine VSLS, bromoform (CHBr3) and dibromomethane (CH2Br2), over a 20-year period (1993-2012). The overarching goal of TransCom-VSLS was to provide a reconciled model estimate of the stratospheric source gas injection (SGI) of bromine from these gases, to constrain the current measurement-derived range, and to investigate inter-model differences due to emissions and transport processes.Models ran with standardised idealised chemistry, to isolate differences due to transport, and we investigated the sensitivity of results to a range of VSLS emission inventories. Models were tested in their ability to reproduce the observed seasonal and spatial distribution of VSLS at the surface, using measurements from NOAA’s long-term global monitoring network, and in the tropical troposphere, using recent aircraft measurements - including high altitude observations from the NASA Global Hawk platform. The models generally capture the seasonal cycle of surface CHBr3 and CH2Br2 well, with a strong model-measurement correlation (r ≥ 0.7) and a low sensitivity to the choice of emission inventory, at most sites. In a given model, the absolute model-measurement agreement is highly sensitive to the choice of emissions and inter-model differences are also apparent, even when using the same inventory, highlighting the challenges faced in evaluating such inventories at the global scale. Across the ensemble, most consistency is found within the tropics where most of the models (8 out of 11) achieve optimal agreement to surface CHBr3 observations using the lowest of the three CHBr3 emission inventories tested (similarly, 8 out of 11 models for CH2 Br2). In general, the models are able to rep

Published
2016
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