This study investigates the dominant modes of the interannual variability of the northern Eurasian winter snowfall during 1982–2020 and explores their potential influencing factors and the associated physical processes. The first and second empirical orthogonal function (EOF) modes feature coherent snowfall anomalies over the high latitudes of Eurasia and western Siberia, respectively. Further analyses indicate that the anomalous atmospheric circulations play a major role in forming the snowfall variability, which could be further attributed to the influences of the atmospheric teleconnection patterns and Arctic sea ice variations. Specifically, the anomalous circulations related to the first EOF mode are mainly contributed by the effects of the teleconnections of the Polar–Eurasian and Scandinavian patterns. The formation of the second EOF mode has a close connection with the North Atlantic Oscillation and the Eurasian pattern. In addition, the sea ice variations over Baffin Bay exert a considerable influence on the snowfall anomalies related to the second EOF mode by exciting a wave train–like anomalous circulation. This effect is further verified by a numerical simulation. An empirical statistical model based on the above influencing factors can well explain the temporal evolutions of the two dominant modes, verifying the important value of our results to improve the understanding of interannual variability of northern Eurasian winter snowfall.

Spring snow cover variability over Northeast China (NEC) has a profound influence on the local grain yield and even the food security of the country, but its drivers remain unclear. In the present study, we investigated the spatiotemporal features and the underlying mechanisms of spring snow cover variability over NEC during 1983–2018 based on the satellite-derived snow cover data and atmospheric reanalysis products. The empirical orthogonal function (EOF) analysis showed that the first EOF mode (EOF1) explains about 50% of the total variances and characterizes a coherent snow cover variability pattern over NEC. Further analyses suggested that the formation of the EOF1 mode is jointly affected by the atmospheric internal variability and the sea surface temperature (SST) anomaly at the interannual timescale. Specifically, following a negative phase of the atmospheric teleconnection of the Polar–Eurasian pattern, a prominent cyclonic circulation appears over NEC, which increases the snowfall over the east of NEC by enhancing the water vapor transport and decreases the air temperature through reducing the solar radiation and intensifying the cold advection. As a result, the snow cover has increased over NEC. Additionally, the tripole structure of the North Atlantic spring SST anomaly could excite a wave-train-type anomalous circulation propagating to NEC that further regulates the snow cover variability by altering the atmospheric dynamic and thermodynamic conditions and the resultant air temperature and snowfall. Our results have important implications on the understanding of the spring snow cover anomaly over NEC and the formulation of the local agricultural production plan.

The summer precipitation in Northeast China (NEC) exerts vital effects on the local crop yield and food security of our country, however, the prediction skill of it is still limited as yet. This study investigated the impact of snow cover anomaly over the Russian Far East during spring (March–April) on the succeeding early summer (May–June) precipitation variability in NEC as well as the underlying physical mechanisms during the years 1961–2020 based on diagnostic analyses and model simulation. The results showed that, on the interannual timescale, the decreased (increased) spring snow cover over the Russian Far East is conducive to the increased (decreased) NEC early summer precipitation. Further analyses indicated that the negative anomaly of spring snow cover can persist into early summer, which then enhances the diabatic heating and thereby warms the overlying atmosphere via the snow‐albedo effect. The warming atmosphere favors the intensified Okhotsk High and an associated prominent anticyclonic circulation over northeast Asia. The anomalous southeast winds on the southwest flank of the anticyclone could bring abundant water vapor to the NEC, induce moisture convergence and ascending motion, and eventually contribute to the above‐than‐normal precipitation. These physical processes operate in the opposite manner in the case of the positive anomaly of spring snow cover. Our findings are beneficial to further improve the understanding and prediction ability of the summer precipitation variability over NEC.