An AeroCom initial assessment -optical properties in aerosol component modules of global models

S. Kinne (1) , M Schulz , C. Textor (2) , S. Guibert (2) , Yves Balkanski (2, 3) , S. E. Bauer (4) , T. Berntsen (5) , T. Berglen (5) , O. Boucher (6) , M. Chin (7) , W Collins , F. Dentener (8) , T Diehl , R Easter , J. Feichter (9) , D. Fillmore (10) , S. Ghan (11) , P. Ginoux (12) , S Gong , A. Grini (5) , J. Hendricks (13) , M. Herzog , L. Horowitz (12) , I. Isaksen (14) , T. Iversen (5) , A. Kirkevåg (5) , S. Kloster (9) , D Koch , J E Kristjansson , M. Krol (15) , A. Lauer , J F Lamarque , G Lesins , X Liu , U Lohmann , V Montanaro , G Myhre , J E Penner , G Pitari , S Reddy , O Seland , P Stier , T Takemura , X Tie

1 MPI-M - Max-Planck-Institut für Meteorologie
2 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
3 MERMAID - Modelling the Earth Response to Multiple Anthropogenic Interactions and Dynamics
4 Columbia University [New York]
5 UiO - University of Oslo
6 United Kingdom Met Office [Exeter]
7 GSFC - NASA Goddard Space Flight Center
8 Climate Change Unit [Ispra]
9 MPI-M - Max Planck Institute for Meteorology
10 NCAR - National Center for Atmospheric Research [Boulder]
11 PNNL - Pacific Northwest National Laboratory
12 GFDL - NOAA Geophysical Fluid Dynamics Laboratory
13 IGN - Institut für Geophysik und Meteorologie [Köln]
14 Department of Geosciences [Oslo]
15 WUR - Wageningen University and Research [Wageningen]

The AeroCom exercise diagnoses multi-component aerosol modules in global modeling. In an initial assessment simulated global distributions for mass and mid-visible aerosol optical thickness (aot) were compared among 20 different modules. Model diversity was also explored in the context of previous comparisons. For the component combined aot general agreement has improved for the annual global mean. At 0.11 to 0.14, simulated aot values are at the lower end of global averages suggested by remote sensing from ground (AERONET ca. 0.135) and space (satel-lite composite ca. 0.15). More detailed comparisons, however , reveal that larger differences in regional distribution and significant differences in compositional mixture remain. Of Correspondence to: S. Kinne ([e-mail]) particular concern are large model diversities for contributions by dust and carbonaceous aerosol, because they lead to significant uncertainty in aerosol absorption (aab). Since aot and aab, both, influence the aerosol impact on the radia-tive energy-balance, the aerosol (direct) forcing uncertainty in modeling is larger than differences in aot might suggest. New diagnostic approaches are proposed to trace model differences in terms of aerosol processing and transport: These include the prescription of common input (e.g. amount, size and injection of aerosol component emissions) and the use of observational capabilities from ground (e.g. measurements networks) or space (e.g. correlations between aerosol and clouds).

Domains: Atmospheric and Oceanic Physics [physics.ao-ph]; Ocean, Atmosphere

S. Kinne, M Schulz, C. Textor, S. Guibert, Yves Balkanski, et al.. An AeroCom initial assessment -optical properties in aerosol component modules of global models. Atmospheric Chemistry and Physics, 2006, 6, pp.1815-1834. ⟨10.5194/acp-6-1815-2006⟩. ⟨hal-02873941⟩