摘要
通过对位于唐古拉山北坡的D1 0 5点不同深度土壤温度时间序列的分析 ,表明各层日平均土壤温度的时间变化具有很好的年周期 ,其变化曲线为一正弦曲线。浅层土壤温度的波动比其较深层土壤温度的波动大 ,但对同一层而言 ,其波动程度尽管在夏半年略大于冬半年 ,但差别不大。地表、0 0 5m和0 2m深处 ,土壤日最高温的变化幅度要明显大于最低温的变化幅度 ;同时 ,日最高温与日最低温的变化趋势并不完全一致。积雪可能对土壤日最高温、日最低温和日温差有较大影响。地表 1a中的最大日温差可达 6 0 4℃ ( 1 998年 3月 2 7日 ) ,1a中极端日最高温可达 39 7℃ ,最低温达 -1 6 5℃。夏半年日温差明显大于冬半年 ,且日温差随深度的增加而减小 ,到 80cm深处已基本上看不到明显的日温差。
The analysis based on the ground temperature at different depths at D105 site,Qinghai\|Tibetan Plateau showed that the variation of daily mean ground temperature at different depths has a one\|year period.The variation is a sine curve.The fluctuations of the ground temperature in shallower layers are larger than that in deeper layers.However,although the fluctuation of ground temperature in summer is a little bit larger than that in winter for the same layer,the difference is not large.On surface,and at \{0\^05 m\} and \{0\^2 m,\}the variation amplitude of the daily maximum ground temperature is larger than that of the daily minimum ground temperature.The maximum daily range of surface ground temperature in the study period is 60\^4℃.The maximum ground temperature on surface is 39\^7℃ and the minimum is -16\^5℃.The daily range of ground temperature in summer season is larger than that in winter and it decreased as the depth increased.There is no evident daily range of ground temperature in \{80 cm.\} Meanwhile,the variation trends of the daily maximum ground temperture and the daily minimum ground temperature are different.The snow cover might affect the daily maximum ground temperature,daily minimum ground temperature and the daily range of the ground temperature.The relative thick snow cover can lead to decrease of the nocturnal long wave radiation on surface and prevent from drop of the minimum ground temperature.Meanwhile,the more important role played by the snow cover is to weaken the short wave radiation received on surface at daytime due to the sudden increase of albedo.This makes the maximum ground temperature on surface decrease substantially.The dual roles of the relatively thick smow cover contribute to the decreasing range of ground temperature.Anyway,the variation of the mean daily ground temperature is not so significant.Due to short of detailed snow cover data in the northern Tibetan Plateau,the above explanation needs further study.
出处
《资源科学》
CSSCI
CSCD
北大核心
2000年第2期77-81,共5页
Resources Science
基金
中国科学院重大项目!KZ95 1-B1-2 12
冰冻圈研究项目
中日GAME-Tibet国际合作项目资助
