新疆塔城区域暴雨时空变化特征及其影响因子分析OACSTPCD

Using the daily observation data of nine national meteorological stations in Tacheng area of Xinjiang,and the atmospheric circulation and sea surface temperature index from National Climate Center during 1960-2022,the spatial-temporal variation characteristics and influencing factors of rainstorm events in Tacheng region were analyzed.The results show that:The rainstorm events occur 125 times in Tacheng area,and the annual average frequency of stations and days is 1.98 d,with a distribution pattern of more in the northwest and less in the central and eastern regions.The annual average rainfall is 6.83 mm,with the maximum value appearing at Tacheng station and the minimum value at Paotai station.The frequency and annual rainfall in Tacheng region show an overall increasing trend.The seasonal distribution of rainstorm frequency shows a single peak type,mainly occurring from May to August,with the most in July.The decadal variation of rainstorm is obvious,from the 1960s to the 2000s the rainstorm is less than the average value during 1991-2020,especially in the 1970s the rainstorm is the least.The rainstorm frequency begins to increase obviously in the 2010s.Western Pacific subtropical high area(intensity,northern boundary position)index are positively correlated with the rainstorm frequency,while the Asian polar vortex area(intensity)index and Northern Hemisphere polar vortex area(intensity)index are negatively correlated with the rainstorm frequency.The cold(warm)ENSO(El Niño-Southern Oscillation)events have a good correspondence with the less(more)rainstorm in Tacheng region.