天山中段雪岭云杉林区辐射特征分析

Radiation characteristics of Picea Schrenkiana forest area in middle Tianshan mountains of China

利用天山中段雪岭云杉林区全年辐射观测资料,分析了云杉林区辐射平衡各分量的年、季节和日变化特征。结果表明:林区辐射平衡各分量呈现出明显的年变化和日变化特征。6-8月的向下短波辐射高于其他月份,12月份出现最小值。向下、向上长波辐射和净辐射通量的变化趋势与之相同,10月开始逐渐减小,最小值出现在12月,3月开始缓慢增加,至7月达到全年最大。而向上短波辐射3月出现最大值,最小值出现在10月。向下、向上短波总辐射均在14:00出现最大值;向下长波辐射日变化不明显,向上长波辐射最大值出现在15:00;净辐射平均日变化在-50～300W/m2之间。不同季节达到最大值、出现最小值的时间有所不同。各季节辐射平衡分量的年平均日总量、占年总量的百分率以及年变化和日变化均存在显著差异。

Based on the observation information of Picea Schrenkianaforest area in middle Tianshan Mountains of China during 2009,annual,seasonal and diurnal variation of short and long-wave radiation and net radiation were analyzed in order to discuss solar radiation characteristics in Picea Schrenkianaforest.The results showed that there were obvious annual variations of components of radiation equilibrium in forest area.The downward shortwave radiation was the highest in summer（from June to August） and the lowest in winter（December）.The same as the downward,upward long-wave radiation and net radiation.They increased gradually from March,and appeared the highest in July,after then decreased gradually from October,and reached the lowest value in December.The contrary of the upward shortwave radiation,and the highest was in March and the lowest was in October.The diurnal variations of components of radiation equilibrium were obvious in forest area,except the downward long-wave radiation.The downward and upward shortwave radiation reached the peak value at 14：00,and the upward long-wave radiation at 15：00.The diurnal variation of net radiation changed from-50 to 300W/m2.There was the difference of time appearing the highest and lowest value in different season.The yearly average of total daily downward and upward shortwave radiation was 15.44 and 5.77MJ/m2,with 23.06,28.55,5.12MJ/m2 of downward,upward long-wave radiation and net radiation.There was significant difference of annual and diurnal variation between the yearly averages of total daily radiation,the global radiation partitioned into components of radiation equilibrium in different season.