资源环境科技发展态势分析平台

Whether sea-ice loss or lapse-rate feedback dominates the Arctic amplification remains an open question. Analysis of datasets based upon observations reveals a 1.11 K per decade surface warming trend in the Arctic (70-90°N) during 1979-2020 cold season (October-February) that is five times higher than the corresponding global mean. Based on surface energy budget analysis, we show that the largest contribution (∼82%) to this cold season warming trend is attributed to changes in clear-sky downward longwave radiation. In contrast to that in Arctic summer and over tropics, a reduction in lower-tropospheric inversions plays a unique role in explaining the reduction of the downward longwave radiation associated with atmospheric nonuniform temperature and corresponding moisture changes. Our analyses also suggest that Arctic lower-tropospheric stability should be considered in conjunction with sea-ice decline during the preceding warm season to explain Arctic amplification.