There are numerous studies on polar amplification and its influence on mid-latitude weather and climate.However,assessments on whether polar amplification occurs in Antarctica are rarely conducted.Based on the latest ...There are numerous studies on polar amplification and its influence on mid-latitude weather and climate.However,assessments on whether polar amplification occurs in Antarctica are rarely conducted.Based on the latest atmospheric reanalysis of ERA5 produced by European Centre for Medium-Range Weather Forecasts(ECMWF),we have defined the Antarctic amplification index,and calculated the trend of annual and seasonal Surface Air Temperature(SAT)mean during 1979-2019 for Antarctic Ice Sheet(AIS)and the trend mean of different meridional sectors of Antarctic sub regions including East Antarctic Ice Sheet(EAIS),West Antarctic Ice Sheet(WAIS)and Antarctic Peninsula(AP).Antarctic amplification shows regional differences and seasonal variations.Antarctica shows a slight warming with the largest magnitude in AP.The temperature anomalies indicate the least fluctuations in austral summer,and the more fluctuations in winter and spring.In austral summer,the warming trend domains EAIS and WAIS,while the cooling trend appears over AP.The zonal mean in Southern Hemisphere maintains a warming trend in the low latitudes,and fluctuates greatly in the middle and high latitudes.The strongest Antarctic amplification phenomenon occurs in spring,with the amplification index of 1.20.For AP,the amplification occurs in austral autumn,and the amplification index is 2.16.At South Pole and the surrounding regions,SAT for land only fluctuates largely and shows different trends in different seasons.The mechanism of Antarctic amplification is unclear till now,and its research suffers from the limitation of measured data.This suggests that future research needs progress in comprehensive ground observation network,remote sensing data accumulation,and high-resolution climate modeling with better representation of both atmospheric and cryospheric processes in Antarctica.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supported by the National Natural Science Foundation of China(Grant No.41671073,41476164)the Freedom Project of the State Key Laboratory of Cryosphere Science,Northwest Institute of Eco-Environment and Resources,CAS(Grant SKLCS-ZZ-2021)。
文摘There are numerous studies on polar amplification and its influence on mid-latitude weather and climate.However,assessments on whether polar amplification occurs in Antarctica are rarely conducted.Based on the latest atmospheric reanalysis of ERA5 produced by European Centre for Medium-Range Weather Forecasts(ECMWF),we have defined the Antarctic amplification index,and calculated the trend of annual and seasonal Surface Air Temperature(SAT)mean during 1979-2019 for Antarctic Ice Sheet(AIS)and the trend mean of different meridional sectors of Antarctic sub regions including East Antarctic Ice Sheet(EAIS),West Antarctic Ice Sheet(WAIS)and Antarctic Peninsula(AP).Antarctic amplification shows regional differences and seasonal variations.Antarctica shows a slight warming with the largest magnitude in AP.The temperature anomalies indicate the least fluctuations in austral summer,and the more fluctuations in winter and spring.In austral summer,the warming trend domains EAIS and WAIS,while the cooling trend appears over AP.The zonal mean in Southern Hemisphere maintains a warming trend in the low latitudes,and fluctuates greatly in the middle and high latitudes.The strongest Antarctic amplification phenomenon occurs in spring,with the amplification index of 1.20.For AP,the amplification occurs in austral autumn,and the amplification index is 2.16.At South Pole and the surrounding regions,SAT for land only fluctuates largely and shows different trends in different seasons.The mechanism of Antarctic amplification is unclear till now,and its research suffers from the limitation of measured data.This suggests that future research needs progress in comprehensive ground observation network,remote sensing data accumulation,and high-resolution climate modeling with better representation of both atmospheric and cryospheric processes in Antarctica.
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.