东北冷涡发生次数和日数气候分析

The Frequency and Days of Northeast Cold Vortex

基于ERA5再分析资料筛选的东北冷涡过程数据,分析1961—2021年东北冷涡过程发生次数和日数气候和气候变化特征,发现:(1)东北冷涡平均每年发生31次,初夏5月最多,晚秋11月最少;冷涡过程持续日数平均4.2 d,6月最长,4月最短;年平均东北冷涡发生日数126.6 d;东北冷涡持续日数多为3-4 d。(2)2000年代和1970年代东北冷涡发生较多,1960年代和1980年代较少;1997年东北冷涡过程最多(39次),1982年最少(20次);东北冷涡过程5月显著增多趋势(速率0.38次/10 a),7月减少趋势(速率0.24次/10 a)。(3)年东北冷涡日数有两次趋势突变,发生在1980年和2017年;5月冷涡日数有两次趋势突变,发生在1990年和2004年。各月和年冷涡日数主要表现为年际尺度振荡。

Based on ERA5 reanalysis data,the frequency and days of the Northeast cold vortex process from 1961 to 2021 were analyzed,and the climate and climate change characteristics were found to be:(1)The NECV occurs an average of 31 times per year,with the highest occurrence in May and the lowest in November;The average duration of NECV process is 4.2 days,with the longest in June and the shortest in April;The annual average days of NECV is 126.6 days;The duration of NECV is mostly 3-4 days.(2)There were more NECV processes in the 2000s and 1970s,and fewer in the 1960s and 1980s;In 1997,there were the most NECV processes(39 times),and the least in 1982(20 times);The NECV process showed a significant increase trend in May(rate 0.38 times/10 a),and a decrease trend in July(rate 0.24 times/10 a).(3)There are two climate mutations in the NECV days,occurring in 1980 and 2017;There were two mutations in May,occurring in 1990 and 2004.The days of NECV in each month and year mainly manifests as interannual scale oscillations.