基于雪雨比的黑龙江省降水相态变化特征分析

Analysis of Precipitation Forms Characteristics in Heilongjiang Province based on Snowfall/Precipitation Ratio

利用1960-2015年黑龙江省27个气象站的日均降水和温度数据,分析了黑龙江省的降雪量和雪雨比长年变化,并对气候变化于降水相态的影响进行了初步的探讨。结果表明,在1960-2015年间,黑龙江省年均降雪量呈显著的上升趋势,气候倾向率达到3.3 mm·(10a)^-1,并于2003年出现了突变,突变后增加了34.3%;降雨量则没有显著变化。以上结果造成黑龙江省的雪雨比显著上升,倾向率为7.6%·(10a)^-1。黑龙江省降雪的多年变化分布呈较为一致的增加趋势,幅度由东向西逐渐降低;降雨分布则表现出复杂的地区差异性,但总体上南部变化幅度大于北部;雨夹雪量变化总体上呈现自东向西递减的趋势,尤其以长白山-大小兴安岭一线为界,东西差异十分明显。雪雨比和降雪的差异主要表现为降雨量发生显著减少的地区雪雨比的显著增加。此外,降雪起始日滞后和结束日提前共同造成了黑龙江省平均降雪季长度的显著缩短,共减少了18天左右。主要原因是春季温度的上升幅度高于秋季,特别是最低气温变化更显著。相比之下年降雪日数没有显著变化;降雪强度则显著增大,趋势为0.8mm·(d·10a)^-1。

The precipitation form(snowfall,rainfall or fleet)have greatly influenced a large number of ecological processes,such as surface runoff,energy flow,and material circulation processes.Obviously,precipitation form is very sensitive to temperature changes.To discuss the effects of climate change on precipitation form,a dataset including average daily rainfall and temperature data of 27 stations from 1960 to 2015 in Heilongjiang province was employed to analyze the long-term change in annual snowfall and snowfall/rainfall ratio.The results indicate that:The annual mean snowfall in Heilongjiang province experienced a sharp growth with 34.3%increase after a break which occurred around the year 2003.The long-term increase rate was 3.3 mm per decade.On the contrary,no significant change was observed in annual mean rainfall in Heilongjiang province.Trend tests showed a 7.6%per decade significant increase in snowfall/rainfall ratio in Heilongjiang.The main characteristic of change in snowfall spatial distribution was consistent upward trend except Huma station,but the amplitude of eastern parts was larger than the western ones.Otherwise,rainfall variation spatial pattern was differed among regions.In general the changes in the southern part were more strongly than the northern.The variation of fleet presented a distinct trend of decreasing from east to west.There was a large difference in fleet between the two sides of The Changbai-Hinggan mountains,presented as a sharp decline from the eastern part of the mountain to the western.The difference in spatial distribution between snowfall/rainfall ratio and snowfall was mainly reflected in the areas where rainfall was significant decreased,such as the western foot of Changbai mountains,where the rain shadow effect was extremely strong.The common impacts of delayed origin date and advanced end date resulted in the snowfall season range evidently shortened about 18 days in the last 56 years.The reason may be attributed to a significant temperature rise in Heilongjiang province.The spring warming should be considered as a major role rather than autumn because of the higher temperature variation,especially the increase in minimum temperature.There was no significantly change observed in average annual snowfall days.The amplitude changed in snowfall frequency in the northern was larger than the southern.Consistent with the snowfall growth,an increased trend of snowfall intensity was found in Heilongjiang,with a changing rate of 0.8 mm per decade.In the context of global warming,higher snowfall rate phenomenon was observed in Heilongjiang province.