Abstract:

Considering the effects of dominant factors including the altitude and temperature on the earth surface air pressure，a distribution model of earth surface air pressure is established based on the pressure － height equation in this paper． The coefficients of this model are calibrated by using the measurement data from the ground meteorological stations and re － analyzed sea level air pressure datasets of NCEP． The spatial distributions of monthly and daily average surface pressure on complicated terrain are simulated under this model． A minor fitting error is obtained in this model with the empirical coefficients which are consistent with the theoretical value．The measurement data from the ground meteorological stations are used to validate the simulation result． The validation absolute mean error is about 1 hPa，which indicates the distribution model has good simulation performance． The spatial distributions of monthly and
daily average surface pressure in 2001，and 30 － year － mean monthly and daily average surface pressure from 1981 to 2010 in China are mapped with the resolution of 1 km × 1 km under this model． The analysis of those distributions shows that the surface pressure of China has a gradient of low to high from west to east． Through the whole year，the lowest pressure appears on the Qinghai － Tibet Plateau in the winter while the highest appears in the eastern coastal areas in winter． The distribution gradient shows the combined effects of the altitude and temperature upon the earth surface air pressure．

Key words: surface pressure, pressure － height equation, re － analyzed datasets of NCEP

摘要：

以压高方程为基础，考虑海拔高度、气温等主导因素对地面气压的影响，建立了地面气压分布模型，并利用地面气象站实测资料和ＮＣＥＰ 再分析海平面气压资料，率定了模型的参数，模拟出复杂地形下月平均气压和日平均气压的空间分布。该模型拟合误差较小，标定得到的模型参数与理论值具有很好的一致性。同时，利用气象站实测数据对气压模型进行了验证，其绝对平均误差为１ ｈＰａ 左右，表明该模型具有较好的模拟性能。最后，制作了１ ｋｍ ×１ ｋｍ 空间分辨率我国２００１ 年月平均气压和日平均气压空间分布图，以及１９８１ ～２０１０ 年３０ ａ 平均月平均气压和日平均气压空间分布图。通过对气压分布图的分析可以看出，我国地面气压呈现西低东高的阶梯状分布，一年之中最高值出现在冬季海拔较低的东部沿海地区，最低值出现在冬季海拔较高的青藏高原地区，反映了海拔高度和气温对地面气压的综合影响。

关键词: 地面气压, 压高方程, ＮＣＥＰ 再分析资料, 分布模型