The cause of cold events over central Asia was investigated. Since 1958, surface air temperature (SAT) has gradually increased over central Asia, but SAT has shown very strong multidecadal fluctuations, with cooling dominant in the 1960s–1970s and recent decades but warming dominant in the 1990s. SAT in February in central Asia has decreased by more than 7 °C compared to that in normal years. Analysis indicates that cold events over central Asia are related to the weakening of the polar vortex, which is indicated by the increase in polar cap height (PCH) and weaker zonal-mean zonal winds. The increase in PCH begins in January in the stratosphere and propagates down to the troposphere in February; it is well reflected in the weakening of zonal-mean zonal winds in the stratosphere in January, which extends to the troposphere in February. The January increase in PCH anomaly is associated with surface conditions in the Arctic region, especially the Barents–Kara seas, where sea level pressure increases substantially in January; high pressure then expands to the southeastern (downstream) branch of the Siberian high in February, bringing cold eastern Siberian air to central Asia.

对中亚寒冷事件的成因进行了调查。自 1958 年以来，中亚的地表气温 (SAT) 逐渐升高，但 SAT 表现出非常强烈的数十年波动，在 1960 年代至 1970 年代和最近几十年以降温为主，而在 1990 年代以变暖为主。中亚地区2月份SAT比常年下降7°C以上。分析表明，中亚的寒冷事件与极地涡旋减弱有关，这表现为极冠高度（PCH）增加和纬向平均纬向风减弱。PCH 的增加从 1 月开始在平流层，并在 2 月向下传播到对流层；这很好地反映在1月份平流层纬向平均纬向风减弱，并在2月份延伸到对流层。1 月 PCH 异常的增加与北极地区的地表条件有关，尤其是巴伦支海-卡拉海，那里的海平面压力在 1 月大幅增加；高压然后在二月扩展到西伯利亚高压的东南（下游）分支，将寒冷的东西伯利亚空气带到中亚。