| Aerosol plays a more and more important role in climate change and has a big uncertainty on climate effect. Aerosol radiative forcing (ARF) can be the measurement of the influence of aerosols on the climate. Related research started relatively early and now it is widely believed that aerosol can offset the rise of global temperatures caused by greenhouse gases to some extent. In China, different aerosol types will cause different aerosol radiative forcing. It is important to quantize the uncertainty of aerosol on the climate effect. The aerosol climate effect is still unknown in this area.We retrieved the single scattering albedo (SSA) and aerosol radiative forcing by using the aerosol optical parameters observed by the Chinese Sun Hazemeter Network from2004and MODIS aerosol product. Based on previous studies, there are big differences in spatial and temporal distribution of aerosol optical depth (AOD) and Angstrom exponents among different ecosystems by using CSHNET. Further work had been done in this paper, climate effect made by human activities and natural conditions had been calculated and analyzed. Reflected radiances at the top of the atmosphere as measured by a spaceborne spectroradiometer are sensitive to both AOT and SSA. On the basis of extensive radiative transfer simulations, it is demonstrated that the combined use of the two measurements allows for the retrieval of SSA at a reasonable accuracy under moderate to heavy aerosol loadings. And the aerosol radiative forcing were calculated by SBDART radiative transfer code in order to assess the aerosol climate effect under the clear sky.The results shows that, central and eastern regions, east coastal area and south China have strong human activities, especially the sulfate aerosols with strong scattering, the single scattering albedo (SSA) are greater than0.90in these areas. Because of the better vegetation and less human activities in agriculture ecosystem in northeast China, SSA shows an absorption feature and the values are between0.80to0.85. The surface is mostly desert and gobi in northwest China and Tibet Plateau, and lack of vegetation in this region, SSA shows a strong absorption feature and the values are less than0.80. However, in some developing industrial cities in northwest China, such as Lanzhou and Fukang, aerosols are composed with mineral and sulfate aerosol, SSAs are between0.80to0.85. In addition, Sanya Bay is located in Hainan where less industrial aerosols exist, sea-salt aerosol is the chief component, the annual averaged SSA is0.87.The aerosol radiative forcing at the top of atmosphere (TOA) is consistent with SSA. The TOA in the regions affected by anthropogenic source aerosols in east and south China presents a cooling effect. And TOA presents a warming effect in the regions where exist more dust or mineral aerosols. Because of a mass emissions of anthropogenic aerosols and the morphologic basin, the cooling effect in Yanting is largest. The warming effect in Erdos is the strongest due to the mineral aerosols from desert and desertification grassland.The located natural aerosol type, anthropogenic aerosol and seasonal factors are the main influence factors of TOA. In winter, there is a long term heating period which would provide much soot aerosols in north China and make the radiative forcing effect appear different feature. The long distance transportation of dust/mineral aerosols in spring will make big impact around north China.In addition, aerosols in atmosphere will absorb the radiance or reflect the radiance into Universe. The radiative forcing near the surface are all cooling down in all the stations and all the aerosol types. The difference is the absorbed aerosols warming the earth-atmosphere system and the scattering aerosols cooling it. Considering the differences of aerosol radiative forcing in different regions, local atmospheric thermal condition and regional circulation form will change in the future.The results also shows that, based on an unified observation network which has been built by using low cost and easy operate LED sun hazemeter, we can get the further results of single scattering albedo and aerosol direct radiation force in different ecological systems. The results which have higher accuracy and value can used to measure the climate effect. Especially in Tibet region, because of the villainous climate conditions, it’s hard to use precision instruments for long-term operation and maintenance work. Therefore, this study also provide a new and convenient way for optical data acquisition and aerosol climate effect estimation in rough terrain. |
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