NWP 模式热量系统误差的动力诊断分析

文章证明了模式在预报时段的位温误差，是由于在模式大气和真实大气中，该时段内位温变化过程的不同而造成的。还证明了原始方程的无加速定理对各强迫因子的线性分解同样适用于研究NWP模式热量误差的成因。对国家气象中心T42L9模式1992年1月和7月预报结果的动力诊断表明，模式对纬向位温分布具有较好的预报能力，但在各纬带也存在明显的误差。通过无加速定理的分解分析，研究了这些误差的成因及改善模式的可能途径。

A Diagnostic Study of Numerical Weather Prediction Systematic Forecast Errors in Heat

It is proved, that NWP systematic forecast errors in that are due to the differential equivalent potential temperature variation processes between the model atmosphere and real atmosphere during the period of validity. And it is also proved that these forcing factors which evoke the thermal variation can be split into various linear terms according to the non-acceleration theorem in a primitive equation. By applying this scheme to diagnose the forecast products of the T42L9 model (the operational model of NMC in China) in January and in July 1992, it was indicated that the model has the ability of forecasting thermal reasonable zonal mean, but there are still great errors in zonal belts, especially in the upper troposphere and low stratosphere levels in mid-latitude as well as near surface. The results of analysis by employing this scheme give reasons for the systematic forecast errors and the potential way of improving the model. And it is also shown that this scheme by applying non-acceleration theorem is an efficient tool to diagnose the NWP models physical processes.