Characteristics of Strong Cold Air Outbreaks in China’s Central and Eastern Mongolian Region between 1970 and 2013

摘要

Strong cold air outbreak tracking has been a key meteorological focal point over the years. With observational data and gridded datasets, we used the “three-dimensional wind speed trajectory inverse method” to trace cold air intrusion tracks that occurred during the winter half-years for the central and eastern parts of Inner Mongolia in 1970–2013. The results indicated that there were a total of 303 northwest and 32 westward tracks intruding from along the north end and southern side of the Altai Mountains, respectively, 118 northward tracks intruding from the two individual sides of the Yablonoi Mountains, and 16 occurrences of “other” tracks. The imminent circulation evolution pattern prior to outbreaks essentially causes three categories of cold air masses to undergo dramatic temperature increases, thereby reducing the impacts of source regional differences on the subject air masses. The measure of the annual frequency reduction in northwest tracks was determined to be 0.41 incidents every ten years, while other tracks’ annual frequencies increased, which essentially implies the probable increase of extreme cold in northeast and central China and an increase in the frequency of continuous cold weather exceeding a three-day span in southern China.