祁连山东北侧夏季零度气温层高度变化研究

Analysis on 0 ℃ Level Height Change in Summer over Northeast Side of Qilian Mountain

分析了祁连山东北侧高空零度气温层高度的变化特征，探讨了零度层高度与地面气温、降水量、空中水汽含量、内陆河流量的相关性特征。研究表明：（1）在20世纪50年代后期和60年代零度层高度明显偏高，80年代明显偏低，60年代后期到70年代零度层高度基本上呈下降趋势，80～90年代呈上升趋势，21世纪前4a又呈下降趋势。（2）5～9月历年零度层高度与地面气温、空中水汽含量的变化在同时间段内基本一致，呈正相关性；而与降水量变化表现出明显的负相关性；与内陆河流量变化相关性不明显。

The change of the 0 ℃ level height in summer over the northeast side of the Qilian Mountain was analyzed, and the relationship between the 0 ℃ level height and surface temperature, precipitation, water vapor content in atmosphere and stream flow of inland rivers were discussed. Results show ： （ 1 ）The 0 ℃ level height was obviously higher than normal in the late 1950s and the 1960s, and lower in the 1980s. It presented downward trend from the late 1960s to 1970s, and upward trend in the 1980s and 1990s, and it downward again in the first 4 years of the 21st century; （2） From May to September, the positive correlation was found between the 0 ℃ level height and surface temperature, water vapor content in atmosphere, and it was negatively correlated with precipitation, and there was low correlation between the 0 ℃ level height and the stream flow of inland rivers.