A Comparison of Two Typical Schemes for Pressure Gradient Force Calculation in Topographic Area

Two typical schemes for pressure gradient force (PGF) calculation in topographic area have been compared. One is that PGF of topographic coordinate is got by vertical interpolating from calculation of constant pressure surface, the other is difference-differential-difference scheme. Based on the initial field diagnosis and forecast verification, the results show that the first scheme does better in upper air while the second scheme in lower air for reducing topographic influence.