Spatio-temporal Characteristics and Atmospheric Circulation Patterns of Strong Cold Air in Inner Mongolia
To explore the climatic characteristics and atmospheric circulation patterns of strong cold air events in Inner Mongolia from 1981 to 2022,this paper identifies the strong cold air events in Inner Mongolia by using daily precipitation and daily minimum temperature data from China Meteorological Administration as well as the NCEP/NCAR reanalysis dataset.Besides,the spatial and temporal characteristics of the strong cold air in Inner Mongolia and the atmospheric circulation types are analyzed by the methods of REOF and synthetic analyses.The results show that,in terms of the spatial distribution of linear trends in strong cold air events,the stations with the increase in cold air events are mostly observed in February.Based on the analysis of occurrence frequency of cold-dry and cold-wet strong cold air events in different regions,Regions 1 and 2 have more cold-dry type events,while Region 3 encounters more cold-wet type events.The long-term variation trends indicate a decreasing tendency in the frequency of cold-dry and cold-wet types of strong cold air events in Region 3,while Regions 1 and 2 show an increasing trend in cold-wet type events and a decreasing trend in cold-dry type events.In summary,the primary condition for the formation of cold-dry type strong cold air processes in each region is the influence of northwest airflow,whereas the formation of cold-wet type strong cold air processes requires the transport of warm and moist airflow from the southeast.
Inner Mongoliastrong cold aircold-dry aircold-wet air
NETL
NSTL
万方数据
