摘要
利用2009年12月27日～2010年4月2日天山积雪站站区内开阔地和雪岭云杉(Picea schrenkiana)林下6次降雪过程后雪层内时间间隔10 min的温度数据,探讨雪层温度变化特征。结果表明,越接近地表雪层温度越高,且在雪层表面形成冷中心和(局部)暖中心;在积雪稳定期林下雪层温度高于开阔地,融雪期林下低于开阔地;林下雪层冷、暖中心出现时间晚于开阔地,其强度也小于开阔地。林下雪层温度振幅小于开阔地,林下温度振幅拐点以上雪层温度振幅随深度和时间的递减率小于开阔地,拐点以下无明显差异。初冬,林下和开阔地雪层均为较小的正温度梯度,随着气温急剧下降,温度梯度逐渐增大,且从雪表向雪底递减,林下雪层负温度梯度出现时间晚于开阔地。开阔地和林下积雪表层正温度梯度最大值分别达到0.95℃/cm和0.82℃/cm,负温度梯度大值分别达到-0.84℃/cm和-0.35℃/cm;但开阔地全雪层日平均温度梯度小于林下雪层。
The snow temperature under Picea schrenkiana forest crown and on the open ground was observed at Tianshan Research Station for Snow-cover and Avalanche of the Chinese Academy of Sciences from Dec 27, 2009 to Apr 2, 2010. The spatial and temporal distributions as well as variations of snow temperature were analyzed in details. The results indicated that there is a higher snow temperature near the ground surface, and local cold and warm centre happen at the snow surface layer. The snow temperature under crown is higher than that on the open ground in stable period, which present a contrary trend in snowmelt period; the low and high tem- perature centre of forest snow appears later and weaker than that on the open ground. Besides, the decreasing rate of snow temperature amplitude with depth and time under crown is lower than that on the open ground above break point, but there is no statistical difference below break point at early stable period. The snow tem- perature gradient is small and positive, and it increases with air temperature decreasing but decreases with depth from surface down. The negative temperature gradient of forest snow appeases later than that on the open ground. Under crown and on the open ground, the maximum positive temperature gradient of snow reach- es 0.95 ℃/cm and 0.82 ℃/cm, and the negative temperature gradient reaches -0.84℃/cm and -0.35℃/cm, respectively. Whereas the whole layer snow temperature gradient under forest crown is larger than that on the open ground.
出处
《地理科学》
CSCD
北大核心
2011年第12期1541-1548,共8页
Scientia Geographica Sinica
基金
干旱内陆区冰雪资源动态监测与可持续利用评估研究项目(GYHY200706008)
新疆现代与历史暖湿化过程及对生态环境影响项目(2005DIB6J113)
新疆生态与地理研究所绿洲学者"博士"人才培养计划(0771021)
中国科学院"西部之光"人才培养计划项目(RCPY200902)资助
关键词
林下积雪
开阔地
雪层温度
温度振幅
温度梯度
snow under forest crown
open ground
snow temperature
temperature amplitude
temperature gradient
