不同控制变量的AMSR2资料同化方法对台风“山神”预报的影响研究-海洋预报

不同控制变量的AMSR2资料同化方法对台风“山神”预报的影响研究

单位：1. 南京信息工程大学气象灾害教育部重点实验室/气候与环境变化国际合作联合实验室/气象灾害预报预警与评估协同创新中心, 江苏南京 210044;
2. 美国国家大气研究中心, 科罗拉多丹佛 80301

分类号：P457.8

出版年·卷·期（页码）：2019·36·第五期（19-29）

摘要：

以2012年生成于太平洋西岸的第23号台风"山神"（Son-tinh）为个例，在WRFDA-3DVar同化系统中结合新型AMSR2同化模块，探讨两种不同的同化背景误差协方差（CV5、CV7）和不同的模式背景场启动机制（冷，热启动）对台风预报影响的研究。结果表明：（1）同化系统的分析场相对于背景场，对AMSR2辐射率资料亮温的模拟，在观测残差、标准差、均方根误差方面均有不同程度的减小。可以很好地模拟出台风的热力学结构，提高模式分析场的质量，从而进一步提高台风预报的准确度；（2）总体而言使用UV风的控制变量方案（CV7）的效果略好于使用流函数和势函数的方案（CV5）。CV7方案的正向温度增量区域大于CV5，尤其是在台风中心区域附近，正向温度增量有助于台风暖心结构的形成；（3）热启动的spin-up过程可以改善模式的热力结构和水汽特征；CV7方案可以在更小尺度上将背景场和观测联系起来且在边界附近产生的误差更小。热启动结合CV7方案对于台风路径的预报最为有效。

Taking No. 23 typhoon Son-tinh generated in the West Pacific Ocean as a case study, we analyze the influence of two different background error covariance (CV5, CV7) and two different background starting mechanisms (cold-start, warm-start) on typhoon forecast using the WRFDA-3DVar assimilation system with the newly developed AMSR2 assimilation module. The results show that the observation error, standard deviation and root-mean-square error is reduced by assimilating the AMSR2 radiance data. In addition, the thermodynamic structure of typhoon is can be well simulated and the quantity of is enhanced, which favors the improvement of typhoon forecast accuracy. The area of positive temperature increment in CV7 scheme is larger than that in CV5 scheme, especially near the area of typhoon. Positive temperature increment favors the formation of typhoon warm core, which results in the slightly better performance of CV7 in typhoon forecast compared to CV5. The spin-up process of warm-start can improve the thermodynamic structure and vapor property of the model. On the other hand, the CV7 scheme could associate background field with observation on a smaller scale and generate less errors near the boundary. As a result, warm-start combined with CV7 scheme is most effective for typhoon track forecast.

参考文献：

[1] Pielke R A, Landsea C W. Normalized hurricane damages in the United States:1925-1995[J]. Weather and Forecasting, 1998, 13:621-631.
[2] 马雷鸣. 国内台风数值预报模式及其关键技术研究进展[J]. 地球物理学进展, 2014, 29(3):1013-1022.
[3] 陈渭民. 卫星气象学[M]. 3版. 北京:气象出版社, 2017:1-21.
[4] Xu D M, Liu Z Q, Huang X Y, et al. Impact of assimilating IASI radiance observations on forecasts of two tropical cyclones[J]. Meteorology and Atmospheric Physics, 2013, 122(1-2):1-18.
[5] 俞兆文, 刘健文, 黄江平, 等. 同化AMSR2微波成像资料对WRF模式暴雨预报的影响[J]. 气象灾害防御, 2017, 24(3):10-14, 29.
[6] 李兴武, 董海萍, 郭卫东, 等. ATOVS不同卫星资料在台风模拟中的同化试验研究[J]. 热带气象学报, 2012, 28(2):157-166.
[7] 王业桂, 张斌, 蔡其发, 等. 微波温湿遥感资料在台风路径模拟中的同化试验[J]. 海洋预报, 2018, 35(1):1-11.
[8] Yang C, Liu Z Q, Bresch J, et al. AMSR2 all-sky radiance assimilation and its impact on the analysis and forecast of Hurricane Sandy with a limited-area data assimilation system[J]. Tellus A:Dynamic Meteorology and Oceanography, 2016, 68(1):30917.
[9] 俞兆文, 刘健文, 黄江平, 等. AMSR2微波成像资料同化试验及其对台风预报的影响[J]. 气象水文海洋仪器, 2017, 34(2):1-8.
[10] Gentemann C L, Hilburn K A. In situ validation of sea surface temperatures from the GCOM-W1 AMSR2 RSS calibrated brightness temperatures[J]. Journal of Geophysical Research:Oceans, 2014, 120(5):3567-3585.
[11] Sun J Z, Wang H L, Tong W X, et al. Comparison of the impacts of momentum control variables on high-resolution variational data assimilation and precipitation forecasting[J]. Monthly Weather Review, 2016, 144(1):149-169.
[12] 祝芳. 1223号强台风"山神"过程分析[J]. 科协论坛(下半月), 2013, (8):134-135.
[13] Xu D M, Min J Z, Shen F F, et al. Assimilation of MWHS radiance data from the FY-3B satellite with the WRF Hybrid-3DVAR system for the forecasting of binary typhoons[J]. Journal of Advances in Modeling Earth Systems, 2016, 8(2):1014-1028.
[14] Li X, Zeng M J, Wang Y, et al. Evaluation of two momentum control variable schemes and their impact on the variational assimilation of radar wind data:case study of a squall line[J]. Advances in Atmospheric Sciences, 2016, 33(10):1143-1157.
[15] 朱乾根, 林锦瑞, 寿绍文, 等. 天气学原理与方法[M]. 4版. 北京:气象出版社, 2007:229-233.
[16] 王叶红, 赵玉春, 李红莉, 等. AREM模式的热启动数值模拟——以2007年7月13日暴雨过程为例[J]. 高原气象, 2011, 30(6):1488-1504.

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