This paper gives an overview of the current understanding of the observations of black carbon(BC) in snow and ice, and the estimates of BC deposition and its radiative forcing over the Arctic. Both of the observations...This paper gives an overview of the current understanding of the observations of black carbon(BC) in snow and ice, and the estimates of BC deposition and its radiative forcing over the Arctic. Both of the observations and model results show that, in spring, the average BC concentration and the resulting radiative forcing in Russian Arctic > Canadian and Alaskan Arctic > Arctic Ocean and Greenland. The observed BC concentration presented a signi?cant decrease trend from the Arctic coastal regions to the center of Arctic Ocean. In summer, due to the combined effects of BC accumulation and enlarged snow grain size, the averaged radiative forcing per unit area over the Arctic Ocean is larger than that over each sector of the Arctic in spring. However, because summer sea ice is always covered by a large fraction of melt ponds, the role of BC in sea ice albedo evolution during this period is secondary. Multi-model mean results indicate that the annual mean radiative forcing from all sources of BC in snow and ice over the Arctic was ~0.17 W m^(-2). Wet deposition is the dominant removal mechanism in the Arctic, which accounts for more than 90% of the total deposition. In the last part, we discuss the uncertainties in present modeling studies, and suggest potential approaches to reduce the uncertainties.展开更多
This study reports on the measurements of ion and refractory black carbon(rBC)concentrations in a shallow(10.96 m)ice core sample which was drilled from the field site of the East Greenland Ice Core Project(EGRIP)in J...This study reports on the measurements of ion and refractory black carbon(rBC)concentrations in a shallow(10.96 m)ice core sample which was drilled from the field site of the East Greenland Ice Core Project(EGRIP)in July,2016.The results provide a recent record of rBC deposition in the East Greenland ice sheet from 1990 to 2016.The annual variability in oxygen(δ^(18)O)and hydrogen(δD)isotopic compositions indicated that notably warm events occurred since 2008.Peaks in rBC occurred during summer seasons,which may be attributed to the burning of biomass in boreal summer.The rBC record and analysis of historical air trajectories using the HYSPLIT model indicated that anthropogenic BC emissions from Russia,North America and Europe contributed to the majority of rBC deposition in the Greenland region,and a reduction in anthropogenic BC consumption in these areas played a dominant role in the decrease in BC concentrations since 2000.This record also suggests that the emissions from the East Asian region(China)contributed very little to the recorded BC concentrations in East Greenland ice core.The model results indicated that radiative forcing due to BC had decreased significantly since 1990,and had remained below 0.02W m^(-2) since 2000.展开更多
基金funded by the Ministry of Science and Technology of China (2013CBA01804)the National Nature Science Foundation of China (41425003, Y51101P1A1)+1 种基金the key project of CAMS: Research on the key processes of Cryospheric rapid changes (KJZD-EW-G03-04)the Opening Founding of State Key Laboratory of Cryospheric Sciences (SKLCS-OP-2016-03)
文摘This paper gives an overview of the current understanding of the observations of black carbon(BC) in snow and ice, and the estimates of BC deposition and its radiative forcing over the Arctic. Both of the observations and model results show that, in spring, the average BC concentration and the resulting radiative forcing in Russian Arctic > Canadian and Alaskan Arctic > Arctic Ocean and Greenland. The observed BC concentration presented a signi?cant decrease trend from the Arctic coastal regions to the center of Arctic Ocean. In summer, due to the combined effects of BC accumulation and enlarged snow grain size, the averaged radiative forcing per unit area over the Arctic Ocean is larger than that over each sector of the Arctic in spring. However, because summer sea ice is always covered by a large fraction of melt ponds, the role of BC in sea ice albedo evolution during this period is secondary. Multi-model mean results indicate that the annual mean radiative forcing from all sources of BC in snow and ice over the Arctic was ~0.17 W m^(-2). Wet deposition is the dominant removal mechanism in the Arctic, which accounts for more than 90% of the total deposition. In the last part, we discuss the uncertainties in present modeling studies, and suggest potential approaches to reduce the uncertainties.
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA19070103)the National Key Research and Development Program of China(2018YFC1406103 and 2018YFC1406104)+3 种基金the National Natural Science Foundation of China(41425003)the Southern Marine Science and Engineering Guangdong Laboratory(Guangzhou)(GML2019ZD0601)the Youth Innovation Promotion Association,CAS(2020419)the Scientific Research Foundation of the Key Laboratory of Cryospheric Sciences(SKLCSZZ-2020-09).
文摘This study reports on the measurements of ion and refractory black carbon(rBC)concentrations in a shallow(10.96 m)ice core sample which was drilled from the field site of the East Greenland Ice Core Project(EGRIP)in July,2016.The results provide a recent record of rBC deposition in the East Greenland ice sheet from 1990 to 2016.The annual variability in oxygen(δ^(18)O)and hydrogen(δD)isotopic compositions indicated that notably warm events occurred since 2008.Peaks in rBC occurred during summer seasons,which may be attributed to the burning of biomass in boreal summer.The rBC record and analysis of historical air trajectories using the HYSPLIT model indicated that anthropogenic BC emissions from Russia,North America and Europe contributed to the majority of rBC deposition in the Greenland region,and a reduction in anthropogenic BC consumption in these areas played a dominant role in the decrease in BC concentrations since 2000.This record also suggests that the emissions from the East Asian region(China)contributed very little to the recorded BC concentrations in East Greenland ice core.The model results indicated that radiative forcing due to BC had decreased significantly since 1990,and had remained below 0.02W m^(-2) since 2000.
