青藏高原融雪期积雪反照率特性分析

Analysis of the Characteristics of Snow Albedo during the Snowmelt Period of the Qinghai-Tibet Plateau

积雪反照率是影响地—气辐射能量平衡的重要地表参数之一。结合青藏高原的积雪消融特点,研究了2018年2~3月青藏高原28个观测点的反照率空间差异,并分析了影响反照率的表层积雪参数,结果表明:融雪期青藏高原的积雪反照率均值为0.72,高原东北部的青海地区观测点的反照率均值高于西藏南部地区,不同区域积雪反照率值内部差异不同;西藏南部地区的水汽来源和较快的积雪消融过程导致该区域反照率低于青海地区;地表被斑状雪覆盖的观测点具有较低的反照率值(小于0.5);多云天气条件下,短时间的云层遮挡对反照率影响很小,积雪反照率几乎保持不变。

Snow albedo is one of the important surface parameters affecting the balance of ground-air radiation energy.Based on the characteristics of snow deposition in the Qinghai-Tibet Plateau,this paper studies the spa⁃tial differences of albedo from 28 observation points in the Qinghai-Tibet Plateau from February to March 2018,and analyzes the surface snow parameters affecting the albedo.The results show that during the snow⁃melt period of the Qinghai-Tibet Plateau,the average albedo of snow cover is 0.72.The albedo of the observa⁃tion points in Qinghai area of the northeastern part of the plateau is higher than that in southern Tibet.The inter⁃nal differences of snow albedo in different areas are different.The source of water vapor in southern Tibet and the faster snow melting process leads to the albedo in this area being lower than that in Qinghai.The observation points covered by patchy snow on the surface have lower albedo values(less than 0.5).In cloudy weather,short-term cloud occlusion has little effect on albedo,which remains almost unchanged.