Assimilation of radar radial velocity data with the WRF hybrid 4DEnVar system for the prediction of hurricane Ike (2008)
Assimilation of radar radial velocity data with the WRF hybrid 4DEnVar system for the prediction of hurricane Ike (2008)
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使用 WRF 混合 4DEnVar 系统同化雷达径向速度数据以预测飓风艾克 (2008)
DOI：
10.1016/j.atmosres.2019.104771
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发表时间：
2020-04
影响因子：
5.5
通讯作者：
Xin Li
中科院分区：
文献类型：
--
作者：
Feifei Shen;Dongmei Xu;Jinzhong Min;Zhigang Chu;Xin Li
四维系综变分同化（4DEnVar）是一种在整个同化窗口内考虑与气流相关的背景误差协方差（BEC）和非同步观测的同化方法，避免了伴随模式的维护。利用天气研究预报和资料同化模式（WRFDA），研究了混合4DEnVar同化径向速度（Vr）资料对飓风Ike分析预报的影响。4DEnVar与集合变换卡尔曼滤波器（ETKF）耦合，通过混合方案更新集合均值，集合扰动由ETKF更新。在真实的飓风Ike（2008）个例前，对典型急流和热带气旋个例进行了单次观测试验。结果表明，分析增量在同化窗口结束时向下游移动。由4DEnVar方法表示的线性传播接近于完全非线性模型积分。对于真实的IKE个例，4DEnVar实验发现了正的和螺旋形的温度增量、最佳路径和强度预报，表明飓风Ike的热力结构更加真实。3DEnVar和3DVar-FGAT由于缺乏空间和时间上的BEC描述而受到限制。3DVar实验在较低层的飓风涡旋中心产生更平滑和更弱的冷温度增量。
Four dimensional ensemble-variation data assimilation (4DEnVar) is the method that considers the flow dependent background error covariance (BEC) and asynchronous observations throughout the assimilation window, which avoids the maintenance of the adjoint model. The impacts of assimilation of radial velocity (Vr) data using hybrid-4DEnVar for the analyses and forecasts of hurricane Ike are investigated using Weather Research and Forecasting and Data Assimilation model (WRFDA). 4DEnVar is coupled with Ensemble Transform Kalman Filter (ETKF) by updating the ensemble mean by the hybrid scheme and the ensemble perturbations are updated by the ETKF. Single observation tests for typical Jet cast and tropical cyclone (TC) case are conducted before the real hurricane Ike (2008) case. It is found that the analysis increment moves downstream by the end of the assimilation window. The linear propagation represented by the 4DEnVar method is close to the full nonlinear model integration. For the real IKE case, it is found that positive and spiral temperature increments, best track and intensity forecast are found in 4DEnVar experiment, indicating a more realistic thermal structure of hurricane Ike. 3DEnVar and 3DVar-FGAT are limited due to the lack of the BEC description spatially and temporally. 3DVar experiment produces much smoother and weaker increments with cold temperature increments at the hurricane vortex center at lower levels.
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影响因子：
5.8
作者：
Feifei Shen;J. Min
通讯作者：
Feifei Shen;J. Min
影响因子：
3.1
作者：
T. Tsuda;T. Inoue;S. Kato;S. Fukao;D. Fritts;T. Vanzandt
通讯作者：
T. Tsuda;T. Inoue;S. Kato;S. Fukao;D. Fritts;T. Vanzandt
影响因子：
3.2
作者：
D. Kleist;K. Ide
通讯作者：
D. Kleist;K. Ide
影响因子：
3.2
作者：
Xuguang Wang;D. Barker;C. Snyder;T. Hamill
通讯作者：
Xuguang Wang;D. Barker;C. Snyder;T. Hamill
影响因子：
5.8
作者：
Wang Bin;Liu Juanjuan;Kuo, Ying-Hwa
通讯作者：
Kuo, Ying-Hwa