Understanding the Cold Season Arctic Surface Warming Trend in Recent Decades

• Published in: Geophysical Research Letters
• Main Authors: Zhang, Rudong, Wang, Hailong, Fu, Qiang, Rasch, Philip J., Wu, Mingxuan, Maslowski, Wieslaw
• Language: unknown
• Published: 2021
• Subjects: 54 ENVIRONMENTAL SCIENCES; Arctic; Sea ice
• Online Access: http://www.osti.gov/servlets/purl/1825481; https://www.osti.gov/biblio/1825481; https://doi.org/10.1029/2021gl094878

Whether sea-ice loss or lapse-rate feedback dominates the Arctic amplification (AA) remains an open question. Analysis of data sets 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 AA.