青海湖表层水温变化特征及对气候变化的响应

Variation Characteristic of Surface Water Temperature and Its Response to Climate Change in Qinghai Lake

分析了青海湖非冰期表层水温变化特征及其对气候变化的响应情况,并对其影响因子和环流背景进行了讨论。结果表明:青海湖非冰期的表层水体温度变化倾向率为0.50℃/10 a,1986年发生突变; 20世纪60年代末至90年代初15～18 a的振荡周期较为明显,20世纪80年代初到21世纪初准9 a周期突出;向下长波辐射和气温是主导因子,降水、近地面空气比湿、地表气压是指示因子;非冰期表层水温受多种大气环流因子的综合作用,与局地环流因子具有更强的相关性。

This paper identified the variation characteristic of surface water temperature as well as its response to climate change, and discussed its influence factors and circulation background. The results show that the surface water temperature during ice-free period of Qinghai Lake has been increasing significantly over the past few decades. The annual average increase rate is about 0.50 ℃ / 10-year and the year 1986 is identified as the turning point of these variations. During the period from late 1960s to early 1990s, a significant oscillation period of 15-18 years is observed. However, from the early 1980s to the early 2000s, the period has decreased to 9 years. In general, the variations of surface water temperature are dominated by downward longwave radiation. Precipitation, near surface air specific humidity, and surface pressure are indictors of its variations. The surface water temperature during ice-free period is controlled by several atmospheric circulation factors, but correlated most to the local circulation factors.