%0 Journal Article %A ZHOU Yaman %A SUN Di %A ZHAO Yong %A LI Anbei %A GUO Yulin %T Characteristics of Wide-range Extreme Precipitation in Summer and Its Circulation Anomalies in Northern Xinjiang#br# %D 2021 %R 10.11755/j.issn.1006-7639(2021)-02-0215 %J Journal of Arid Meteorology %P 215-224 %V 39 %N 2 %X Based on daily precipitation data at 45 meteorological stations of northern Xinjiang and NCEP/NCAR reanalysis data from June to August during 1961-2017, the threshold of summer extreme precipitation events was determined by using percentile method in northern Xinjiang. The temporal variation characteristics of summer extreme precipitation with different grades and their relationship with maximum daily precipitation in summer and corresponding monthly precipitation were analyzed in northern Xinjiang. The precipitation distribution of twelve cases for wide-range summer extreme precipitation with five-level was clustered by using Euclidean distance method, and on this basis their circulation characteristics were discussed emphatically. The results show that the frequency of summer extreme precipitation with different grades (except for four-level) presented significant rising trend in northern Xinjiang during 1961-2017. The daily precipitation at most stations during the wide-range extreme precipitation process was the maximum daily precipitation in summer of the same year, and the averagely accounted for 28.6% of corresponding monthly precipitation in northern Xinjiang. There were three patterns for the distribution of wide-range summer extreme precipitation in northern Xinjiang. The axis of 200 hPa westerly jet in western Asia subtropical zone was southward, and the westerly winds enhanced in the south of 40°N. The cold air moved southward under the guidance of Ural high pressure ridge, the low value system was active in West Siberia or Central Asia, and the high pressure system was strong in downstream Baikal region on 500 hPa, but the location, range and intensity of these systems were different, which led to different falling areas of wide-range extreme precipitation. Meanwhile, there were anomalous cyclonic and anti-cyclonic water vapor flux anomalies in Central Asia and the lower reaches of eastern Xinjiang, respectively, and the anomalous southward or eastward water vapor transport in northern Xinjiang provided favorable conditions for wide-range extreme precipitation. %U http://www.ghqx.org.cn/EN/10.11755/j.issn.1006-7639(2021)-02-0215