黑龙江省冬季异常暖气候事件判定及其与环流指数的关系

利用1961-2018年黑龙江省61个站冬季逐日平均气温资料,以连续5 d日平均气温正距平超过1倍标准差为标准,对黑龙江省冬季异常暖事件进行了判断,并按照0.3个标准差将其分为一级、二级、三级异常暖气候事件。分析表明黑龙江省在58年间冬季共发生35次异常暖气候事件,累计天数270 d。异常暖气候事件发生有较明显的周期性变化,1961-1986年和2009-2018年为低发期、1987-2008年为高发期。71.4%的异常暖事件发生在1986年后,说明异常暖事件的频繁发生对1980年代中后期该省冬季气温显著升高有直接贡献。1961-2018年该省冬季发生一级、二级、三级异常暖气候事件分别为9次、10次、16次。研究月尺度同期环流指数异常与黑龙江省异常暖气候事件的关系,发现北半球极涡面积异常偏小、极涡强度异常偏强、东亚槽强度异常偏弱和北极涛动异常正位相与异常暖气候事件发生有较好的对应关系,为今后黑龙江省冬季异常暖气候事件的预测提供了可靠参考。

Determination of Winter Abnormal Warm Climate Events in Heilongjiang Province and its Relationship with Circulation Index

Based on the winter daily average temperature data of 61 stations in Heilongjiang Province from 1961 to 2018, the winter abnormal warm climate events in Heilongjiang Province are judged by taking the positive anomaly of daily average temperature over 1 standard deviation for 5 consecutive days as the standard, and are divided into first, second and third abnormal warm climate events according to 0.3 standard deviation. The analysis shows that there are 35 abnormal warm climate events in winter in Heilongjiang Province in 58 years, with a total of 270 days. The occurrence of abnormal warm climate events has obvious periodic changes, with low occurrence period in 1961-1986 and 2009-2018 and high occurrence period in 1987-2008. 71.4% of the abnormal warm climate events occurred after 1986, indicating that the frequent occurrence of abnormal warm climate events contributed directly to the significant increase of winter temperature in the province in the middle and late 1980 s. From 1961 to 2018, level Ⅰ, Ⅱ and Ⅲ abnormal warm climate events occurred in the province in winter for 9, 10 and 16 times respectively. By studying the relationship between the monthly scale anomaly of the circulation index and the abnormal warm climate events in Heilongjiang Province, it is found that the abnormal area of polar vortex in the northern hemisphere is smaller, the intensity of polar vortex is stronger, the intensity of East Asian trough is weaker, and the positive phase of Arctic Oscillation anomaly is in good correspondence with the occurrence of abnormal warm climate events. It provides reliable predictions for future abnormal warm climate events in winter in Heilongjiang Province.