Impact of the Western Tibetan Vortex on Springtime Snow Cover Over the Western Tibetan Plateau

Snow cover changes are of great importance to the hydrological cycle of the western Tibetan Plateau (TP). However, the influence of the atmospheric circulation on snow cover over the western TP is still unclear. This study finds that springtime snow cover variability over the western TP tail is significantly modulated by the Western Tibetan Vortex (WTV), which explains up to 40% variance. Cyclonic (anticyclonic) WTV variability generally causes water vapor convergence (divergence) and ascending (sinking) motions over the western TP tail, which thereby leads to more (less) snowfall and snow cover about one day later. Horizontal water vapor transport at the southern boundary of the western TP tail from the tropical Indian Ocean is key for the influence of the WTV. This study elucidates the impact of the WTV on springtime snow cover, which augments our understanding of the hydrological cycle over the western TP.