摘要
利用全球/区域同化与预报系统GRAPES(Global/Regional Assimilation and Prediction System)和改进的Mellor-Yamada型海洋混合层模式OMLM(Ocean Mixed Layer Model),建立了一个新的中尺度海-气耦合模式GRAPES_OMLM,并利用该模式对发生于南海的台风珍珠(0601)进行了模拟研究,检验了GRAPES_OMLM对台风的模拟性能,并分析了局地海-气相互作用对台风的影响。结果表明,GRAPES_OMLM基本能模拟出台风天气过程中的主要物理过程。考虑了海-气相互作用的耦合试验所模拟出的台风强度、近台风中心最大风速以及台风后期移动路径,相对于两组控制试验(单独大气模式)的模拟结果都有较大的改进。而且,采用逐日变化海表温度作为下边界条件的控制试验2的模拟结果相对于SST不变的控制试验1更接近观测。耦合模式GRAPES_OMLM能较好地模拟出台风过境海表温度的变化,台风珍珠在其路径右侧有超过4.0℃的降温。SST的变化和海表风应力的变化呈反相关系,风应力的增大伴随着海洋近表层湍流动能(TKE)的加强,大风动力作用是SST降低的主要原因。SST的降低致使海洋向台风输送的热通量减少,进而削弱了台风的强度并改变台风环流结构,同时通过改变位势涡度趋势的一波结构(WN-1)来影响台风的移动路径。
A new mesoscale coupled air-sea model was developed based on the Global/Regional Assimilation and Prediction System （GRAPES） with the improved Mellor-Yamada type Ocean Mixed Layer Model （OMLM） employed. Using this GRAPES OMLM model, Typhoon Chanchu （2006） was simulated to test the ability of the GRAPES_OMLM in typhoon research and in- vestigate the impact of local airea interaction on typhoon. The results show that the GRAPES_OMLM is able to catch the main physical processes of the typhoon weather. The simulated minimum surface pressure, maximum wind near the typhoon center and the typhoon＇s track in the coupled model where the air-sea interaction is included are better consistent with the ob- servation than those in the uncoupled model. Furthermore, compared to the experiment Ctrl_l with unchanged SST condition, the results of the Ctrl_2 in which daily mean SST is adopted have a bit improvement as well. The SST simulated in the coupled model is also very close to the observation with the maximum SST cooling of more than 4.0~C, which is located at the right of Chanehu＇s track. There is an inverse correlation between the change of SST and the surface wind stress, and the increasing of wind stress will induce TKE＇s rise with wind-inducing mixing as the main reason for the SST cooling. Moreover, SST cooling can weaken the typhoon＇s intensity and change the typhoon＇s circulation structure through reducing the heat flux from the ocean, as well as change the WN-1 structure of the Potential Vorticity Tendency which affects the typhoon＇s track.
出处
《气象学报》
CSCD
北大核心
2012年第2期261-274,共14页
Acta Meteorologica Sinica
基金
国家重点基础研究发展计划(2009CB421403)
财政部、科技部公益性行业(气象)科研专项(GYHY200806007)
中国科学院项目百人计划暨知识创新工程重要方向项目(KZCX2-YW-BR-14)
关键词
耦合模式
台风模拟
局地海-气相互作用
Coupled model, Simulation of typhoon, Local air-sea interaction
