Assessment Of CAM5and Climate Effect Of Primary Organic Aerosol

Large uncertainties have been found, when investigate the role of aerosol in climatechange. Organic aerosol (OA), due to its complex properties of physics, chemistry and optics,has became one of the hottest topics in research of climate change. In order to quantitativelystudy the performance of OA in atmosphere, especially in climate system of East-Asia, weemploy the Community Atmosphere Model, version5, which is the latest version developedprimarily at the National Center for Atmospheric Research (NCAR). The major conclusionsare as follows:1) Two aerosol modules of CAM5.0are used to simulate several main aerosols andexamined respectively. Both of the two modules give a reasonable simulation result of sulfate(SO4), black carbon (BC) and organic carbon (OC) aerosols, when compared with surfaceobservation from Interagency Monitoring of Protected Visual Environments Program(IMPROVE) and European Monitoring and Evaluation Program (EMEP), within a factor of2for SO4and3for BC and OC. Big differences have found in results of the second organicaerosol (SOA) between the two models, while the results of primary organic aerosol (POA)are similar. After tuning the factor of dust emission and factor of sea salt deposition inMOZART, this model can simulate a better dust and sea salt concentration, which is closed tomedian model results on AeroCom website.2) Our simulation performance a reasonable balance of radiation of the Earth andatmosphere, every item of budget has a small enough related error (no more than5%)compared with observation. The changes in net flux of short wave radiation on top ofatmosphere coursed by POA are-0.037and-0.028, in January and July, respectively. At thesame time, the net flux of long wave radiation on top of atmosphere change+0.053and-0.292, respectively, in which the changes of long wave cloud forcing cannot be neglect.Changes in net flux of short wave radiation at surface and surface downwards long waveradiation are both important in regional heating. Under these changes of heating, surfacetemperature change+0.027K in January and-0.013K in July. Rain at middle of Africa, wherethe largest column concentration of POA appears, is suppressed in both January and July.3）With effect of monsoon, the high contribution of POA in China to aerosol optic depth (AOD) occur in south of China in January but in north in/YR]. Z Y YYXVXOYJI ZU UYTI Z aZchanged vapor explain70%~80%of the increase of AOD. Changes of AOD make net flux ofshort wave radiation on top of atmosphere on East-Asia change-2.10W/m~2in January and-4.61W/m~2in July, respectively, which indicates that cloud short wave forcing contributesmore in summer. Changes in net flux of short wave radiation at surface are more importantthan changes in surface downwards long wave radiation in East-Asia, whenever in summer orwinter. The area change of surface temperature in East-Asia is-0.23K in January and-0.46Kin winter. Monsoon has an obvious response: POA of China cool down the east of China, thus,strengthen in winter monsoon, and make drier in most of China mainland in January, while inJuly, POA of China cool down most of east China, especially in north of China, and makedrier in middle of China, but wetter in the south as well as northeat.