第二届未来大气科学论坛

Northern Xinjiang, a major center of winter snowfall in China, has experienced a trend of increasing heavy snowfall events under the background of global warming. Changes in interannual variability (IV) are an essential measure of climate change, alongside shifts in the climatic mean state. This study documented the change in IV of early-winter snowfall over northern Xinjiang (Snow_XJ) during 1961–2023 and its relationship with Arctic sea ice. Results indicated an increment of >50% in snowfall IV over most of northern Xinjiang after the 1990s. During 1961–1990, the main factors responsible for Snow_XJ were the Scandinavian pattern (SCA) and meridional displacement of the East Asian polar front jet (EAPJ). During 1996–2023, Snow_XJ was influenced most by the Arctic Oscillation (AO) and EAPJ intensity. Additionally, the October Arctic sea ice anomalies associated with Snow_XJ were located in the Laptev–East Siberian seas (Greenland–Barents seas) before (after) the 1990s. The sea ice anomalies in the Laptev–East Siberian seas were associated with the SCA pattern through eastward propagation of Rossby wave trains from the Pacific Arctic to Asia, and with the meridional location of the EAPJ via modulation of the poleward temperature gradient during 1961–1990. The sea ice anomalies in the Greenland–Barents seas modulated both the AO phase via stratospheric polar vortex anomalies and the intensity of the EAPJ by inducing temperature anomalies over Asia after the 1990s. The larger IV of sea ice in the Greenland–Barents seas than that in the Laptev–East Siberian seas likely contributed to the enhanced Snow_XJ IV after the 1990s.

Interannual variability,winter snowfall in northern Xinjiang,Arctic sea ice,Scandinavian pattern,Arctic oscillation