西藏高原高寒草甸能量平衡闭合研究

运用OLS线性回归和计算EBR能量平衡比率的方法,以当雄草原站2003~2005年的通量数据为基础,对西藏高寒草原的能量平衡闭合状况进行了研究。研究结果表明,当雄草原站存在着能量不完全闭合的现象,OLS线型回归斜率偏低。生长季能量闭合状况好于非生长季,白天好于夜晚,晴天好于阴天和雨雪天气。随后对能量不闭合的原因进行了初步分析。将潜热通量、显热通量以及土壤热通量的时间提前后,能量闭合程度提高。得出结论,由于热量传输速率的差别,在很大程度上影响了能量的闭合。其他原因如采样的误差与仪器的误差、高频和低频的损失、其他能量项的忽略、平流的损失,也造成了部分能量的不闭合。

Study on the Energy Balance Closure of Alpine Meadow on Tibetan Plateau

Through adopting the means of OLS Linearity return and calculating EBR energy balance,and based on the three-year flux amount data of Damxung rangeland station,we conducted a research on the energy balance closure aiming at the Tibet Plateau alpine meadow.The results show that,there exists a phenomenon of in-complete closure of energy and the slope of OLS curve is relatively low.The closure condition of energy balance in growing season is better than that in non-growing season;day-time is better than night;fine day is better than windy,rainy or snowy days.Later on,we have an analysis on the reason in energy in-closure.When the time of latent heat fluxes,sensible heat fluxes and soil heat fluxes is advanced,the closure condition of energy balance is improved.We draw a conclusion that the difference in the rate of heat transference has a great impact on the energy balance closure.Other reasons as the deviations in samples and instrument,the loss of high frequency and low frequency,the ignorance of some energy item and loss of advection have also contributed to the in-closure of energy balance.