Grapes模式预报西南地区夏季2m温度的检验评估

Verification of 2m Temperature Prediction of Grapes Model in Summer Season in Southwest China

利用西南地区2004、2005年夏季的实况温度对G rapes模式输出的2m温度预报产品进行检验,结果表明,不管是单日预报误差还是月平均预报误差,都没有随预报时效的延长而增大,对四川盆地大部分地区,模式预报温度偏高,对重庆、云南、贵州及川西高原南部的温度预报,基本上表现为14时偏高,02时偏低,对川西高原北部和西藏则表现为预报温度偏低。分析表明,模式中对高原地形处理的不真实是温度预报产生误差的重要原因之一,利用回归分析方法能对模式温度预报进行有效的订正。检验分析结果为进一步改进模式,提高要素预报产品质量提供了一定的依据。

Verifications of 2m temperature prediction by Grapes model in Southwest China during summer of 2004 and 2005 were under- taken. Results show that both daily and monthly mean prediction errors do not increase with forecast time going forward. Temperature prediction in most area of Sichuan basin are higher compared to the observation. The 02：00BJT temperature prediction is lower and the 14：00BJT temperature prediction is higer than observation in Chongqing, Yunnan, Guizhou and southern part of western Sichuan plateau. Temperature prediction in northern part of western Siehuan plateau and xizhang are lower compared to the observation. Analyses show that the unreal topography in model is one of the reason causing temperature errors and through regression analysis to temperature amendment is effective. Verification results in this paper provide some bases for improve the model and its product quality.