鄂陵湖湖滨地区夏季近地层微气象特征与碳通量变化分析

利用2010年夏季鄂陵湖湖滨地区试验观测资料,从中选取资料较好的5个连续晴天,分析了该地区高寒草甸夏季局地气候、辐射与能量平衡特征以及碳通量的日变化。结果表明：①夏季晴天湖滨地区近地层气象要素受到湖陆风的较大影响,风向昼夜交替变化,垂直风速和摩擦速度明显大于玛曲草原,全天盛行上升气流,昼夜温差较小;②湖滨地区日均太阳总辐射与净辐射高于玛曲草原和金塔绿洲,地表能量不平衡现象较显著,湍流输送以潜热为主,夜间近地层存在明显的逆温和逆湿现象;③夏季湖滨草甸碳吸收的日最大值出现在上午11时前后,碳吸收显著大于碳排放,其水分利用效率与海北草甸生态系统接近,总体偏低。

Analysis of Micrometeorology and CO_2 Flux Characteristics over Lake Ngoring Lakeside Region in Summer

In this paper,by using the measured data observed in Lake Ngoring lakeside region during the summer of 2010,five fine days with continuous and integrated data are selected,and then their characteristics of daily variations of the surface radiation and energy budget and CO2 flux and microclimate are analyzed over the high-cold meadow vegetation ecosystem in summer.The main conclusions can be drawn as follows.(1) For fine summer weather,the characteristics of micrometeorology are significantly affected by the lake breeze in lakeside region,not only the wind direction changes alternately but also the difference in temperature is relatively small between day and night.In addition,the updraft prevails in lakeside region,and the vertical wind speed and the friction velocity are much greater than those in Maqu grasslands.(2) The daily mean values of solar radiation and net radiation are larger than those in Maqu grasslands and Jinta oasis.As to the energy budget,the latent flux is significantly higher than the sensible flux,and the energy imbalance is large in the observation.There are distinct temperature inversion and humidity inversion phenomena in the surface layer at the night.(3) The maximum value of carbon absorption usually is observed at about 11o’clock every morning over the meadow in lakeside region,and carbon absorption is significantly more than carbon emission.In terms of the water use efficiency(WUE),it is small,which is similar to that in Haibei meadow.