资源环境科技发展态势分析平台

This study investigates how El Niño-Southern Oscillation (ENSO) modulates winter cold anomalies over central Eurasia using reanalysis data during 1950-2019. It is found that ENSO can significantly influence winter air temperature over central Eurasia mainly through modulating the strength and location of the cyclonic anomaly of Ural blocking (UB) or long-lived UB events. A strong (weak) cyclonic anomaly of UB on the southeastern (eastern) side of the Ural Mountains tends to occur over midlatitude (high-latitude) Eurasia during La Niña (El Niño) winters. Such anomalous circulation leads to a strong (weak) cold anomaly over central Eurasia, especially over East Asia, due to enhanced (weakened) cold air advection toward the central Eurasia during La Niña (El Niño). The UB-related cyclonic anomaly in the midlatitude (high latitude) side of Eurasia is shown to be related to weakened (enhanced) eastward extension of strong westerly winds over midlatitude Eurasia during La Niña (El Niño) winters.