Assessment of future Antarctic amplification of surface temperature change under different Scenarios from CMIP6

Global warming may result in increased polar amplification,but future temperature changes under different climate change scenarios have not been systematically investigated over Antarctica.An index of Antarctic amplification(AnA)is defined,and the annual and seasonal variations of Antarctic mean temperature are examined from projections of the Coupled Model Intercomparison Project Phase 6(CMIP6)under scenarios SSP119,SSP126,SSP245,SSP370 and SSP585.AnA occurs under all scenarios,and is strongest in the austral summer and autumn,with an AnA index greater than 1.40.Although the warming over Antarctica accelerates with increased anthropogenic forcing,the magnitude of AnA is greatest in SSP126 instead of in SSP585,which may be affected by strong ocean heat uptake in high forcing scenario.Moreover,future AnA shows seasonal difference and regional difference.AnA is most conspicuous in the East Antarctic sector,with the amplification occurring under all scenarios and in all seasons,especially in austral summer when the AnA index is greater than 1.50,and the weakest signal appears in austral winter.Differently,the AnA over West Antarctica is strongest in austral autumn.Under SSP585,the temperature increase over the Antarctic Peninsula exceeds 0.5℃when the global average warming increases from 1.5℃to 2.0℃above preindustrial levels,except in the austral summer,and the AnA index in this region is strong in the austral autumn and winter.The projections suggest that the warming rate under different scenarios might make a large difference to the future AnA.

跨尺度代价聚合网络

弱纹理区域由于包含信息少,且在代价聚合网络使用3D卷积计算消耗大,提出跨尺度代价聚合网络。特征提取网络使用残差网络结合注意力机制模块提取多尺度特征,构建多尺度匹配代价集,再将匹配代价集分别进行采样融合生成低分辨率视差图,最后经过优化层得到高精度的视差图。该算法在KITTI数据集上进行评估,整个图像区域的匹配精度(D1-all)和速度上均取得较好的结果。

Does polar amplification exist in Antarctic surface during the recent four decades?

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.