摘要
基于新疆北部1961-2009年43站逐日降水资料,分析了北疆冬季降水的气候分布及时间变化特征.结果表明:北疆冬季降水存在明显的区域差异,北疆西部是降水量和降水日数最多的区域.相对夏季,冬季降水受地形影响规律不明显,这与两个季节形成降水的云物理微观过程的环境条件差异有关.冬季降水呈明显的增加趋势,其中小雪表现为减少趋势,中雪和大雪为增加趋势,大雪尤为显著.降水量和降水日数都具有明显的年代际变化特征,1985-2005年处在高值期,2005年后二者呈减少趋势.降水量主要以6a和14a的周期变化为主,而降水日数的主周期为6a和12a.北疆冬季降水具有较好的持续性特征,持续天数在2d及以上的降水过程可占总降水过程的50%左右.持续性降水量和降水日数可占总降水量和降水日数的60%以上,北疆西部和阿勒泰北部地区超过70%.持续性降水和非持续性降水均呈增加趋势,但是以前者的增加为主,尤其在伊犁河谷地区.
Based on the daily precipitation data at 43 stations in Xinjiang Region from 1961 to 2009,the climatic distribution and temporal variation characteristics of winter precipitation were analyzed.It is revealed that the distribution of winter precipitation had evident regional difference,and the precipitation amount and precipitation days in the west of northern Xinjiang Region were the most.Compared with that in summer,the effect of terrain on precipitation was not so obvious in winter,which was related to the environmental condition of cloud microphysical process.The precipitation amount in winter increased temporally as follows： evidently increased in moderate and heavy snowfall,especially in heavy snowfall,but decreased in light snowfall.Both the precipitation amount and the precipitation days had pronounced decadal variation,high from 1985 to 2005 and decreasing after 2005.The changing of precipitation amount had the period of 6 a and 14 a mainly,and the changing of precipitation days had the period of 6 a and 12 a.The precipitation in winter had good continuity,and the frequency of continuous precipitation of 2 d or more was about 50% of the total precipitation process in winter.The percentages of continuous precipitation amount and precipitation days to the total precipitation amount and precipitation days were more than 60%,and exceeded 70% in the west of northern Xinjiang Region and the north of Altay Prefecture.An increasing trend can be seen in the continuous precipitation and discontinuous precipitation,and the increasing continuous precipitation was more remarkable,especially in Yili River valley.
出处
《冰川冻土》
CSCD
北大核心
2011年第2期292-299,共8页
Journal of Glaciology and Geocryology
基金
公益性行业(气象)科研专项(201106006)
中央级科研院所基本科研业务费专项(IDM200804)资助
关键词
冬季降水
气候变化
持续性和非持续性
北疆
winter precipitation
climate change
persistent and non-persistent
northern Xinjiang
