中文摘要：

2014年3月融雪期间在阿尔泰山额尔齐斯河河源区,基于已有的气象和积雪（雪深、雪密度）观测,利用Snow Fork雪特性仪和便携式温度计TP3001,选择草地、水泥地和河冰三种不同的下垫面分别观测了分层积雪密度、液态水含量和雪层温度变化.结果表明：三种下垫面上表层积雪的温度、液态水含量和密度变化规律基本一致.积雪特性的差异主要体现在积雪层底部,河冰和草地与积雪接触面温度日变化过程呈现出“单峰型”,而与水泥地接触面上的温度日变化呈现出“双峰型”;河冰上积雪底部的液态水含量最小且日变化幅度较小,草地次之,水泥上积雪底部液态水含量的波动最大;水泥和草地上底部积雪的密度变化趋势一致,为密实化过程,而河冰上积雪底部的积雪因深霜层的形成致使雪密度逐渐减小.对同一下垫面上的积雪而言,水泥和草地上积雪温度的极大值出现在雪层中间,河冰上雪层的温度廓线沿雪深有波动上升的趋势,最大值出现在积雪与河冰的接触面处.三种下垫面上积雪的液态水含量最大值均出现在中间雪层,雪密度均呈现沿雪深增加而递减的变化趋势.液态水含量受积雪温度的控制,当积雪温度低于-3℃时,积雪中的液态水可以忽略不计;当积雪温度低于-1℃时,积雪的液态水含量低于1%;当积雪温度大于-1℃时,积雪中出现液态水的比例显著增加,且液态水含量的波动范围较大,最高可到6.2%.

英文摘要：

The available meteorological and snow data and the snow property data, such as snow density, water content and snow cover temperature on three underlying surfaces （ grassland, fiver ice and cement concrete） from March 8 to 25 in the Irtysh River sources of the Altay Mountains observed by instruments, Snow Fork and portable thermometer （TP3001） were analyzed. It is found that there was almost no effect of underlying surface on the temperature, water content and snow density of the surface snow within 0 to 5 cm; the difference caused by underlying surface appeared at the bottom of the snow cover only. The diurnal variation of temperature at the bottom of snow cover showed ＂unimodal style＂ on the grassland and fiver ice surfaces, but ＂bimodal style＂ on the surface of cement concrete ; the diurnal variation of water content at the bottom of snow cover was minimum, following by grassland, and the diurnal variation amplitude of water content was maximum on the cement concrete surface; the snow density at the bottom of snow cover gradually increased on grassland and cement concrete surfaces, but decreased on river ice surface. In terms of vertical variations of snow properties, it was revealed that maximum temperatures of the whole snow cover presented at the middle on grassland and cement concrete surfaces, but at the bottom of snow cover on river ice surface. The minimum water content was found at the middle. And the snow density decreased with depth on all three underlying surface. The liquid water was negligible when the snow temperature was below -3 ℃. The liquid water content was below 1% when the snow temperature varied from -3 ℃ to -1 ℃. The liquid water content and its amplitude were great, ranging from 0 to 6.2%, when the snow temperature was above -1 ℃.