对流参数化方案的改进对GRAPES模式台风预报的影响研究  

THE INFLUENCE OF AN IMPROVED CUMULUS PARAMETERIZATION SCHEME ON TYPHOON FORECAST FROM GRAPES MODEL

作　　者：徐道生[1] 陈子通[1] 戴光丰[1] 钟水新[1] 杨兆礼[1] 

机构地区：[1]中国气象局广州热带海洋气象研究所/广东省区域数值天气预报重点实验室,广东广州510080

出　　处：《热带气象学报》2014年第2期210-218,共9页Journal of Tropical Meteorology

基　　金：公益性行业(气象)科研专项(GYHY201206010);广东省科技计划项目(2012A061400012;2011A032100006)共同资助

摘　　要：将由NCEP改进之后的SAS(Simplified Arakawa-Shubert Scheme)对流参数化方案(NSAS方案)应用到GRAPES模式中,并对"启德"台风进行模拟,通过和原来SAS方案的预报结果进行比较,发现新方案对台风路径预报有显著改进。通过对NSAS方案中几个新增加的因素进行敏感性试验,发现其中对由于对流引发的扰动气压场如何影响动量输送这个问题的处理使得台风路径预报效果变差,采用动量的水平混合代替风场切变来对扰动气压场进行参数化以后,可有效改进该方案的预报效果。考虑动量的水平混合系数随高度变化可进一步改善预报结果。通过比较多个台风的预报结果发现,这种改进对台风路径预报的改进较稳定。The NSAS scheme, a simplified Arakawa-Shubert scheme （SAS） for cumulus parameterization improved by NCEP, is introduced into the GRAPES model. A typhoon case （KAITAK） is simulated with the NSAS scheme and the result is compared with the original SAS scheme. The result is shown as follows. The typhoon track forecast is much better with the NSAS scheme. It is demonstrated that the impact of the convection-induced pressure gradient force on momentum transmission in the new scheme has negative effects on the forecast of typhoon track, a result found through performing sensitivity tests of the new added elements in the NSAS scheme. The forecast can be effectively improved by using the horizontal exchange of momentum to replace vertical wind shear for parameterization of pressure gradient force. Better results are expected to obtain by implementing the exchange coefficient of horizontal momentum that varies with height. The improvement is reliable based on comparisons between several typhoon cases.

关 键 词：对流参数化 SAS 台风 动量输送 

分 类 号：P456.7[天文地球—大气科学及气象学]