1961-2021年黑龙江省春播期东北冷涡气候影响特征OACSTPCD

Using daily surface precipitation and temperature data from 62 stations in Heilongjiang province from 1961 to 2021 and the National Centers for Environmental Prediction/the National Center for Atmospheric Research(NCEP/NCAR)reanalysis data,we statistically analyzed the characteristics of Northeast China Cold Vortex(NC-CV)that lasted 3 days or more during the spring sowing period and its impact on climatic factors.The results show that a total of 233 NCCV events occurred on a total of 958 days during the spring sowing periods of 61 years.The occurrence frequency and day numbers of NCCV exhibited an increasing trend,and the occurrence frequency of NCCV had a significantly negative correlation with the duration of a single cold vortex.The precipitation contribu-tion of NCCV was about 43.29%,and the frequency of heavy precipitation days and rainstorm days during NCCV processes was relatively high,being 48.66%and 59.46%,respectively.The NCCV had no significant impact on air temperature during the spring sowing period.At 500 hPa geopotential height field,there was a good positive correlation between the NCCV and the blocking high area from Lake Baikal to Okhotsk Sea.More than 30%of the NCCV activities were accompanied by the Okhotsk blocking high.The Okhotsk blocking high enhanced the cold vortex precipitation,but had no significant effect on the low temperature during the NCCV process.