The aerosol-climate model ECHAM5-HAM

[摘要] The aerosol-climate modelling system ECHAM5-HAM is introduced. It is based ona flexible microphysical approach and, as the number of externally imposedparameters is minimised, allows the application in a wide range of climateregimes. ECHAM5-HAM predicts the evolution of an ensemble of microphysicallyinteracting internally- and externally-mixed aerosol populations as well astheir size-distribution and composition. The size-distribution is representedby a superposition of log-normal modes. In the current setup, the majorglobal aerosol compounds sulfate (SU), black carbon (BC), particulate organicmatter (POM), sea salt (SS), and mineral dust (DU) are included. Thesimulated global annual mean aerosol burdens (lifetimes) for the year 2000are for SU: 0.80 Tg(S) (3.9 days), for BC: 0.11 Tg (5.4 days), for POM: 0.99Tg (5.4 days), for SS: 10.5 Tg (0.8 days), and for DU: 8.28 Tg (4.6 days). Anextensive evaluation with in-situ and remote sensing measurements underscoresthat the model results are generally in good agreement with observations ofthe global aerosol system. The simulated global annual mean aerosol opticaldepth (AOD) is with 0.14 in excellent agreement with an estimate derived fromAERONET measurements (0.14) and a composite derived from MODIS-MISR satelliteretrievals (0.16). Regionally, the deviations are not negligible. However,the main patterns of AOD attributable to anthropogenic activity arereproduced.

[学科分类] 大气科学