1960~2019年塔城地区春秋季大降水气候特征及环流分型

Nearly 60 Years Age Season End Region Climate Characteristics of Precipitation and Circulation Parting Zone

摘要: 利用近60年(1960~2019年)塔城地区7个气象台站春、秋季逐日降水量资料，运用数理统计方法分析了塔城地区春秋季大降水的气候统计特征及变化特征；利用NECP/NCAR再分析资料，对春秋季大降水的环流形势进行天气学分型，结果表明：塔城地区春秋季大降水极值为64.6 mm，出现于塔城站(2015年9月21日)；春秋季单日大降水出现次数比过程大降水多近2倍，且以5月最多，3月最少；春秋季单日大降水以21世纪10年代最多，其后依次为1980年代、21世纪初年、1970年代和1990年代，最少为1960年代；春秋季过程大降水以21世纪10年代最多，其后依次为1960年代、21世纪初年、1980年代、1970年代，最少为1990年代；春秋季大降水出现次数线性倾向率及气候趋势系数均表现为增多趋势，其中乌苏、塔城、裕民、沙湾分别以0.31 mm/10a、0.2.0 mm/10a、0.20 mm/10a、0.12 mm/10a的速率不显著增多(未通过显著性检验)；春秋季单日大降水降水变率均小于过程大降水降水变率，表明单日大降水较过程大降水稳定；根据主要影响系统，把造成塔城地区春秋季大降水的大气环流分成4种类型，即：西北气流型、欧洲脊发展，乌山大槽东移型、低槽(低涡)东移型、里海长脊，西西伯利亚低槽东移。

Abstract: Based on the data of daily precipitation in spring and autumn of seven meteorological stations in Tacheng area in recent 60 years (1960 - 2019), the climate statistical characteristics and variation characteristics of heavy precipitation in Tacheng area in spring and autumn were analyzed by mathematical statistics method. By using NECP/NCAR reanalysis data, the circulation pattern of spring and autumn heavy precipitation was calculated. The results showed that the extreme value of spring and autumn heavy precipitation in Tacheng area was 64.6 mm, which appeared at Tacheng station (September 21, 2015). In spring and autumn, the occurrence times of one-day heavy precipitation are nearly 2 times more than that of the regular heavy precipitation, and the precipitation is the most in May and the least in March. The largest amount of precipitation in spring and autumn was in the 2010s, followed by the 1980s, the early 2000s, the 1970s and the 1990s, and the least was in the 1960s. In the spring and autumn period, the largest amount of precipitation was in the 2010s, followed by the 1960s, the early 21st century, the 1980s and the 1970s, and the least was in the 1990s. The linear trend rate and climate trend coefficient of the occurrence times of heavy precipitation in spring and autumn show an increasing trend. Among them, the rates of Wusu, Tacheng, Yumin and Shawan are not significantly increased (failing the significance test) at 0.31 mm/10a, 0.2.0 mm/10a, 0.20 mm/10a and 0.12 mm/10a, respectively. In spring and autumn, the precipitation variability of one-day heavy precipitation is lower than that of course heavy precipitation, indicating that one-day heavy precipitation is more stable than that of course heavy precipitation. According to the main influencing systems, the atmospheric circulation that causes heavy spring and autumn precipitation in Tacheng region is divided into four types: northwest air current type, European ridge type, Wushan trough moving to the east, low trough (low vortex) moving to the east, Caspian Ridge type and west Siberia low trough moving to the east.