【摘要】 利用黑龙江省1961-2013年地面测站62站资料和月环流特征量、北半球500hPa高度场等资料,采用气候统计方法,选取秋季地面最低温度≤0℃的初日作为初霜冻日期,分析了初霜冻日期的时空变化特点,北半球500hPa月平均环流演变特征,影响初霜冻早晚的特征量因子,为初霜冻趋势预测提供依据。结果表明:黑龙江省初霜冻日期呈现显著推迟的趋势,推迟约8.2d,平均推迟5d以上的年份均在1988年以后出现;平均初霜冻日期分布是由北开始出现并向南推进,平原则普遍晚于同纬度的山区,EOF分析初霜冻的发生除具有一致性气候特征外,还具有南北相反和东西相反的变化趋势;初霜冻偏早年时,北半球500hPa环流从前期到同期在黑龙江省北部至极地区域有大范围的负距平,反之,若是正距平,初霜冻易偏晚;影响初霜冻早晚的特征量的因子有欧亚(亚洲)经向环流型、鄂霍茨克海高压、阿留申低压、东亚大槽强度以及西太平洋副热带高压、极涡、AO等。更多还原

【Abstract】 Based on the data from62 stations in Heilongjiang Province from1961 to2013,monthly circulation characteristics and500 hPa height field in the northern hemisphere,the first day of the lowest ground temperature≤0℃ in autumn is selected as the first frost date by using climatic statistics method. The temporal and spatial variation characteristics of the first frost date,the monthly mean circulation evolution characteristics at500 hPa in the northern hemisphere and the characteristic factors affecting the early frost and the late frost are analyzed,which provide the basis for forecasting the trend of the first frost. The results show that the first frost date in Heilongjiang Province shows a significant temporal postponement trend of about8.2 days. The year with an average delay of more than5 days has appeared after1988. Spatially,the first frost appears in the order from north to south and from plain to mountains along a latitude. EOF analysis shows that the occurrence of the first frost not only has the consistent climate characteristics,but also has opposite trend from north to south and from east to west. In the early first frost years,the500 hPa circulation in the Northern Hemisphere has a large negative anomaly in the northern and polar regions of Heilongjiang Province from the early stage to the same period,and the cold air activity is frequent;on the contrary,if there is a positive deviation,the first frost is prone to be late. The characteristic factors affecting the early frost are the meridional circulation pattern in Eurasia(Asia),the Okhotsk high,the Aleutian low,the strength of the East Asian trough,the subtropical high in the Western Pacific,the polar eddy,AO and so on.更多还原