黄土高原地表能量平衡分量年际变化及其对气候波动的响应

Plateau surface energy balance components and interannual variability in response to climate fluctuations

本文利用兰州大学半干旱气候与环境观测站(SACOL站)2006—2012年陆面过程观测资料和榆中站气象资料,分析了7年间榆中气温降水的气候变化背景,讨论了陆面地表能量平衡分量的年际变化,研究了波文比、能量闭合度的年际波动,探讨了地表能量平衡分量以及各陆面过程参数对黄土高原气温、降水年际波动的反馈.结果显示,地表各能量分量都对气候背景的波动做出响应,但敏感性各有不同,净辐射与气温相关性最强,感热潜热与降水相关性较好.分为冬夏半年讨论后得出,冬半年地表平衡分量与气候波动的相关性更好.冬半年中,各分量又与气温有着较高的相关,可见该地区地表能量各分量对冬半年气温波动的响应更为敏感.波文比的上升趋势与该地区降水量减少的背景响应,说明干旱程度的加深.能量闭合度的波动变化显示了在气候变化的背景下该地区陆面能量不闭合程度的加深.

In this paper land surface observations and meteorological data are received from Semiarid Climate and Environment Observatory of Lanzhou University （SACOL） and Yuzhong Station from 2006 to 2012. The climate changes of temperature and precipitation in the seven years are analyzed in Yuzhong, and the inter-annual variation of the components of surface energy balance in land surface is discussed. The Bowen ratio and the energy inter-annual fluctuation imbalance are also studied. Explorations of surface energy balance components as well as the land surface process parameters feedback on the temperature, precipitation interannual fluctuations on the Loess Plateau are carried out. Results show that the surface energy components are responsible to the fluctuations of the climate background. But the sensitivity varies; the net radiation and air temperature are more relevant to each other, and the sensible heat and latent heat have a better correlation with precipitation. Discussions are divided into summer and winter half year results, in which the winter half year balance component surface has a better correlation with climatic fluctuations. In the winter half year, each component has a high degree of correlation with temperature, showing that in this area each component of the land surface energy balance component corresponding to the change of temperature is more remarkable The rising trend of Bowen ratio is corresponding to the reduction of precipitation, indicating that the drought is deepened The change of the energy closure shows that the deepening of energy balance unclosure is due to the change of the climate background.