位势高度计算中气压-高度公式的简化及其误差

Simplification of Barometric Height Formula in Geopotential Height Calculation and Resulted Errors

对高空气象学领域而言,位势高度是重要的一个参量,为天气学和气候学业务应用所提供的高度一般是位势高度。位势高度通常采用探空所实时测量的温度、气压和湿度来计算,计算公式为气压-高度公式(简称压高公式)。本文针对压高公式进行了推导分析,并指出公式中简化的由来以及定量计算了简化所引起的误差,分析表明,压高公式中的重力加速度变量若用当地不同高度的实际重力加速度来代替现行的恒定值,将会减小位势高度的计算误差。

The geopotential height is usually calculated with the measured temperature,pressure and humidity,and the calculation formula is called barometric height formula.In this paper,we analyze the derivation of the formula and point out that the origin of the simplified formula.The errors caused by the simplification are calculated quantitatively.The analysis shows that the gravitational acceleration in the barometric height formula should be the local actual variable value instead of the current constant value,and the replacement can reduce errors of the potential height calculation.