摘要
受自然条件和观测数据的限制,对青藏高原腹地高时间频次积雪融雪动态过程的认识与研究仍不足,利用高原中部沱沱河地区野外观测试验场2013/2014年冬半年积雪深度和气温数据,对发生在11月期间的积雪动态融雪过程及其与气温的关系进行了分析。结果表明,高原中部地区融雪过程表现为先缓后急的总体特征,融雪在雪深较小的后期迅速加快。雪深变化与气温存在紧密联系,融雪过程发生之前3 h之内的气温都显著影响雪深变化,雪深变化与超前30 min及同步气温相关最为显著,线性相关系数分别达到-0.3600和-0.3589,通过了0.01显著性水平检验。考虑温度的滞后效应,沱沱河地区雪深下降在温度>-13℃时就可发生,-4^-2℃是主要消融温度区间,这个温度明显低于中国其他山区积雪消融的临界温度。融雪过程主要发生在12:00-18:00期间,且存在12:00-13:30与16:30-18:00两个快速下降时段,值得注意的是,热量状况最好的14:00-16:00雪深下降并不显著。融雪期日照时数与雪深的相关系数为-0.845,融雪前期气温对雪深影响大于日照时数对雪深的影响,融雪后期日照时数对雪深影响大于气温对雪深的影响,均通过0.01显著性检验水平。融雪过程与热量条件及日照时数间的复杂关系表明,青藏高原腹地积雪的消融与日照时数、雪的形态、消融程度、升华过程等均有一定联系。
The recognition and research of high-frequency dynamic snow-melting process in hinterlands of QinghaiXizang Plateau are insufficient due to the restriction of natural conditions and observation data. In this paper,every-30-minute snowdepth and air temperature synchronous observation data of Tuotuohe area in the winter of 2013-2014 are used to investigate the dynamic snow-melting process in November and its relationship with air temperature. The results indicate that the snowin the Central Qinghai-Xizang Plateau melts slowly at first but then quickly during the whole snowmelt process,and especially rapidly during the last period. The change of snowdepth is closely related to the air temperature. 3 hours before the snowmelting,temperature will significantly affect snowdepth change. Significant correlation exists between snowdepth and simultaneous or advanced 30 minutes air temperature. The linear correlation coefficients can reach-0. 3589 and-0. 3600 respectively under significant test of0. 01. Considering the lag effect of temperature,the snowmelting has occurred at-13 ℃. The main snowmelting temperature range is from-2 ℃ to-4 ℃,which is obviously lower than the snow-melting critical temperature in other mountainous areas of China. The snowmelting process mainly occurred during the period of 12： 00-18： 00. In addition,the snowdepth decreases rapidly during 12： 00-13： 30 and 16： 30-18： 00. It should be noticed that the snowdepth has no obvious variation from 14： 00 to 16： 00,which seems to supply good heat condition. The correlation coefficient between the snowdepth and the sunshine duration is-0. 845. In the early stage of snowmelting process,air temperature has a stronger impact on snowdepth than the sunshine duration,and oppositely in the last stage. Snowmelting process has a complex relationship with heat conditions and sunshine duration,indicating that snowablation is certainly contacted with solar radiation,ablation status,snowcharacters and sublimation process.
出处
《高原气象》
CSCD
北大核心
2017年第1期24-32,共9页
Plateau Meteorology
基金
国家自然科学基金项目(41173085
31560671)
公益性行业(气象)科研专项(GYHY201306054)
关键词
青藏高原
积雪
融雪动态
气温
The Qinghai-Xizang Plateau
Snowcover
Dynamic snow-melting process
Air temperature
