祁连山海北高寒湿地微气象季节变化特征

The Seasonal Changes of Micro-Climate in Haibei Alpine Wetland in the Qilian Mountains

对青海海北高寒湿地2004年的微气象观测资料分析表明：海北高寒湿地地—气长短波辐射、地表反射率、能量通量各分量、动量通量、气温、地温、风速、CO2交换量等季节变化明显。因受湿地下垫面性质影响,地表反射率在1～2月明显大于其他季节,7～10月小,表现出冬季高夏季低的“U”型变化特征。地面长波有效辐射无明显季节变化。分析还表明,海北高寒湿地夏季及春、秋季均为明显的热源,而在寒冷的冬季出现一定的“冷源”效应。海北高寒湿地地—气间CO2交换量季节变化明显,年内4月和10月分别存在两个CO2释放高峰期,夏季的7～8月为一个强吸收期。

The data of micro-meteorology were analyzed in Haibei alpine wetland of Qinghai in 2004,the results show that the surface-atmospheric long-wave/short-wave radiation,earth′s surface reflectivity（A）,the components of energy flux,moment flux（τ）,air temperature,soil temperature,wind speed,friction velocity,CO2 exchange,have obvious seasonal changes.Because of the special features of soil surface and plant vegetation in alpine wetland ecosystem,A was higher in January and February than other months,while lower from July to October,which was characterized by ／!U／＂ sharp and bigger in winter while smaller in summer.The seasonal changes of surface long-wave effective radiation were not obvious.Meanwhile,the results suggested that it was an obvious heat source from spring to autumn,and a ／!cold island／＂ in winter in Haibei alpine wetland.As to the seasonal variations of daily CO2 exchange,it was evident,which there were two climaxes of CO2 emission in April and October while strong CO2 absorption in July and August.