海拔误差影响气温空间插值误差的研究

Study on Error and Its Pervasion of Temperature Estimation

利用气象站点的气象要素值进行空间内插以获取无气象站点区域的气象要素值是有关陆地表层过程研究中首先要解决的问题。气温是重要的气象要素之一,海拔高度对气温影响非常显著。论文利用美国地质调查局EROS数据中心生产的全球数字高程模型(GTOPO30)和中国地面气象资料分析了气温内插的点误差及其空间扩散的问题。分析表明,由于中国气象站点地理位置(经纬度)存在有±30″的误差,忽视地理位置的误差将导致的气温点误差为-5.3～+8.6℃,而且点气温误差随着空间内插扩散到其它相邻的像元。

Estimation of temperature in no meteorological observation area is an important step in land surface process study.Altitude is one of the important proxies to estimate temperature. GTOPO30 is a global digital elevation model (DEM).Elevations in GTOPO30 are regularly spaced at 30-arc seconds (approximately 1 kilometer).GTOPO30 was used to meet the needs of the geospatial data user community for regional and continental scale topographic data. GTOPO30 and China meteorological data are applied in this study to analyze the estimated temperature error in each meteorological station and its pervasion during interpolation.The vertical temperature lapse rate is applied and assumed constant (0.0065℃/m) in China.The result shows that temperature error is between -5.3～+8.6℃ due to altitude difference between GTOPO30 and observed value.Error in point (meteorological station) diffuses to neighboring cells in the process of interpolation.Therefore,estimation of temperature as well as other climate parameter must take into consideration of the altitude difference between DEM and observed value.