Contributions of the troposphere and stratosphere to CH 4 model biases

Autor: Wang, Zhiting, Warneke, Thorsten, Deutscher, Nicholas, Notholt, Justus, Karstens, Ute, Saunois, Marielle, Schneider, Matthias, Sussmann, Ralf, Sembhi, Harjinder, Griffith, David, Pollard, Dave, Kivi, Rigel, Petri, Christof, Velazco, Voltaire, Ramonet, Michel, Chen, Huilin
Přispěvatelé: Institut für Umweltphysik [Bremen] (IUP), Universität Bremen, Centre for Atmospheric Chemistry [Wollongong] (CAC), University of Wollongong [Australia], Institute of Environmental Physics [Bremen] (IUP), University of Bremen, Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette] (LSCE), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Modélisation INVerse pour les mesures atmosphériques et SATellitaires (SATINV), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ), Institute for Meteorology and Climate Research (IMK), Karlsruhe Institute of Technology (KIT), Institut für Meteorologie und Klimaforschung - Atmosphärische Umweltforschung (IMK-IFU), Karlsruher Institut für Technologie (KIT), Finnish Meteorological Institute (FMI), ICOS-RAMCES (ICOS-RAMCES), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)
Jazyk: angličtina
Rok vydání: 2017
Předmět:
Zdroj: Atmospheric Chemistry and Physics
Atmospheric Chemistry and Physics, European Geosciences Union, 2017, 17 (21), pp.13283-13295. ⟨10.5194/acp-17-13283-2017⟩
Atmospheric Chemistry and Physics, 2017, 17 (21), pp.13283-13295. ⟨10.5194/acp-17-13283-2017⟩
ISSN: 1680-7316
1680-7324
DOI: 10.5194/acp-17-13283-2017⟩
Popis: International audience; Inverse modelling is a useful tool for retrieving CH 4 fluxes; however, evaluation of the applied chemical transport model is an important step before using the inverted emissions. For inversions using column data one concern is how well the model represents stratospheric and tropospheric CH 4 when assimilating total column measurements. In this study atmospheric CH 4 from three inverse models is compared to FTS (Fourier transform spectrome-try), satellite and in situ measurements. Using the FTS measurements the model biases are separated into stratospheric and tropospheric contributions. When averaged over all FTS sites the model bias amplitudes (absolute model to FTS differences) are 7.4 ± 5.1, 6.7 ± 4.8, and 8.1 ± 5.5 ppb in the tropospheric partial column (the column from the surface to the tropopause) for the models TM3, TM5-4DVAR, and LMDz-PYVAR, respectively, and 4.3 ± 9.9, 4.7 ± 9.9, and 6.2 ± 11.2 ppb in the stratospheric partial column (the column from the tropopause to the top of the atmosphere). The model biases in the tropospheric partial column show a latitudinal gradient for all models; however there are no clear latitudinal dependencies for the model biases in the stratospheric partial column visible except with the LMDz-PYVAR model. Comparing modelled and FTS-measured tro-pospheric column-averaged mole fractions reveals a similar latitudinal gradient in the model biases but comparison with in situ measured mole fractions in the troposphere does not show a latitudinal gradient, which is attributed to the different longitudinal coverage of FTS and in situ measurements. Similarly, a latitudinal pattern exists in model biases in vertical CH 4 gradients in the troposphere, which indicates that vertical transport of tropospheric CH 4 is not represented correctly in the models.
Databáze: OpenAIRE
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