Response of the lower troposphere to moisture intrusions into the Arctic

Abstract

Abstract Water vapor intrusions (WVIs) explain a significant fraction of total moisture transport and its variability in the Arctic. WVIs can precondition the Arctic atmosphere for accelerated melting of sea ice through effects on surface longwave radiation. Using data from the NASA's A‐Train convoy of satellites to estimate the response of the lower troposphere to WVIs into the Arctic, we show that WVIs are associated with a surface warming of up to 5.3 K (±3.3 K) in winter and 2.3 K (±1.6 K) in summer, when averaged over the entire Arctic Ocean. The intrusions also lead to additional cloud radiative heating of up to 0.15 K/d via up to 30% increased cloudiness in the vertical and also cause a weakening of the stability in the lower troposphere. The lower tropospheric and surface warming during winter and spring highlights the importance of understanding contribution of preconditioning to accelerated ice melt in the Arctic.