【摘 要】
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Black carbon (BC) is now concerned as one of the most significant factors impacting environment and climate mainly from anthropogenic activities.One aspect of its impacts is that the accelerated snow
【机 构】
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China National Climate Center(CNCC),Beijing 100081,China;State Key Laboratory of Cryospheric Science
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Black carbon (BC) is now concerned as one of the most significant factors impacting environment and climate mainly from anthropogenic activities.One aspect of its impacts is that the accelerated snow and ice in nature when BC is deposited in their surfaces.Since 2000,18 High Asia glaciers have been surveyed for black carbon deposition 22 times,and numerous snow samples and ice cores have been collected by researchers.However,most of the results were interpreted individually in papers.Here,we assemble the data and discuss the distribution of BC deposition and its impacts on the melting of the glaciers through radiative forcing.We find that BC distribution on the surfaces of High Asia glaciers primarily depends upon their elevations (i.e.,higher sites have lower concentrations) and then on regional BC emissions associated with surface melting conditions.BC concentrations in High Asia glaciers are similar to the Arctic and western American mountains but are significantly less than heavy industrialized areas such as northern China.Although Himalayan glaciers,which are important due to their water resources,are directly facing the strong emissions from South Asia,their mean BC is the lowest due to high elevations.A new finding indicated by ice core records suggested great valleys in the eastern Himalayan section are effective pathways for BC entering the Tibetan Plateau and makes increasing BC trends in the local glaciers.On average,BC deposition causes a mean forcing of ~6 W m-2 (roughly estimated 5% of the total forcing) in High Asia glaciers and therefore may not be a major factor impacting the melting of most glaciers.
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