A dynamic link between spring Arctic sea ice and the Tibetan Plateau snow increment indicator

Abstract

Tibetan Plateau snow has long been recognized as a sensitive indicator of climate variability. However, the commonly used snow indicator cannot fully represent the interannual variability in late autumn Tibetan Plateau snow. Here, we establish a snow indicator for Tibetan Plateau snow variability: the snow cover extent increment within late autumn. This snow increment indicator improves the standard deviation by 72.6% and diabatic cooling by 89.7% over the entire Tibetan Plateau, which shows a robust link to the subsequent spring Arctic sea-ice concentration. Faster Tibetan Plateau snow cover extent increment leads to stronger Tibetan Plateau cooling and disturbance along the subtropical westerly jet, thereby inducing a Tibetan Plateau-Arctic wave train and a spring Arctic cyclonic anomaly. This cyclonic system favors the reduction in spring Arctic sea-ice by equatorward sea ice drift, implying a link between spring Arctic sea-ice and the Tibetan Plateau snow increment indicator through the wave train and sea-ice dynamic processes.