GRAPES云量方案对台风云系演变特征的模拟分析及改进试验

发布时间：2018-03-01 15:29

本文关键词： 台风云量数值模拟云方案对比分析　出处：《中国气象科学研究院》2017年硕士论文　论文类型：学位论文

【摘要】：GRAPES模式中新引进云方案后,已有前人做了一些评估工作,但考虑到台风云系的特殊性和海表与地表差异,针对台风云系和海域上空云系却并未做专门研究。本文首先用GRAPES_Meso模式对2015年13号台风苏迪罗进行了数值模拟,从台风生成发展、成熟和登陆减弱三个阶段对模拟云量和云高(相当黑体温度,TBB)与实况资料进行了初步对比分析,发现了一些问题,然后针对发现的问题或不足,再通过一些数值试验试着对云方案进行了部分改进和调整,初步得到以下几点结论:1)GRAPES模式较好地再现了台风“苏迪罗”从生成发展到成熟再到登陆的过程,模拟的台风路径与实况吻合较好,台风强度的变化趋势也得到了较好模拟再现。2)改进云方案之前,总的看来,模式较好地模拟出了苏迪罗云系整体范围,但模拟存在的不足主要体现在:(a)总云量和高云量明显较实况(再分析)云量偏强,范围偏大;(b)模拟云高较实况偏低。3)针对上述两个问题,对GRAPES模式的云量方案进行修改和完善,重点解决模式模拟的总云量和高云量偏多偏强和云顶高度偏低的问题,并同时对1513号台风苏迪罗和1614号台风莫兰蒂进行了改进前后的对比数值试验。4)数值试验结果表明,(a)对台风发展阶段和成熟阶段的模拟效果看,改进前和改进后三个高度的云量均有不同程度的减弱,覆盖范围也相应有所减小,其中高云量的减弱最明显,改进后高云量和总云量与实况更加吻合。改进后TBB即亮温较改进前稍有降低,即改进后模拟的云顶更高,更加接近卫星实况。(b)对于处于消散阶段的台风即登陆台风,其强度迅速减弱,改进前和改进后三个高度的云量均有不同程度的减弱,其中高云量的减弱更明显,改进后高云量和总云量与实况更加吻合。中低云量改进效果不是很理想。改进后TBB即亮温较改进前稍有降低,即改进后模拟的云顶有少许提高,与实况云高更加接近。(c)改进后的TBB均方根误差在不同区域有不同程度的减小,整体预报效果略有提升。5)总之,尽管改进云方案对台风云系三个阶段的改进效果不统一,但总体上改进后的云方案模拟效果更好,尤其是改进后总云量、高云量和云高明显与实况更加接近。
[Abstract]:After the new cloud scheme was introduced into the GRAPES model, some evaluation work has been done, but considering the particularity of typhoon cloud system and the difference between sea surface and surface, The typhoon cloud system and the cloud system over the sea area have not been specially studied. In this paper, the GRAPES_Meso model is used to simulate typhoon No. 13 Sudiro on 2015 and to develop from the generation of typhoon. In the three stages of maturation and weakening of landfall, the simulated cloud amount and cloud height (quite blackbody temperature) are compared with the actual data, and some problems are found, and then the problems or deficiencies are pointed out. Through some numerical experiments, the cloud scheme has been partially improved and adjusted, and the following conclusions have been obtained preliminarily: 1 / 1 grapes model is a good reappearance of the process of typhoon Sudiro from generation to maturity to landfall. The simulated typhoon track is in good agreement with the actual situation, and the variation trend of typhoon intensity is also well simulated. 2) before the cloud scheme is improved, the overall range of Sudiro cloud system is well simulated by the model. However, the shortcomings of the simulation are mainly reflected in the fact that the total cloud amount and high cloud amount of the simulation are obviously stronger than those of the real (reanalysis), and the range of the simulated cloud height is lower than that of the real ones. 3) in view of the above two problems, we modify and perfect the cloud cover scheme of the GRAPES model. Focus on solving the model simulation of the total cloud amount and high cloud amount on the strong side and cloud top height on the low side, At the same time, the comparative numerical test of 1513 typhoon Sudiro and 1614 typhoon Moranti before and after improvement. 4) numerical test results show that the simulation effect of typhoon development stage and mature stage is seen. Before and after the improvement, the cloudiness of the three heights decreased in varying degrees, and the coverage decreased accordingly, among which the decrease of high cloud cover was the most obvious. The improved TBB is slightly lower than that before the improvement, that is, the simulated cloud top is higher, which is closer to the satellite reality. The intensity of the cloud decreased rapidly, and the cloudiness of the three heights decreased in varying degrees before and after the improvement, among which the decrease of high cloud cover was more obvious. The improved high cloud cover and total cloud cover are more consistent with the actual conditions. The improvement effect of low and medium cloud cover is not very satisfactory. The improved TBB (brightness temperature) is slightly lower than that before the improvement, that is, the simulated cloud top is slightly increased after the improvement. The root-mean-square error (RMS) of the improved TBB is reduced in different regions, and the overall prediction effect is slightly improved. 5) in short, although the improved cloud scheme is not uniform in the three stages of the wind and cloud system, But the simulation effect of the improved cloud scheme is better, especially the total cloud amount, high cloud cover and cloud height are more close to the actual situation.
【学位授予单位】：中国气象科学研究院
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P458.124

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