Effects of the Assimilation of Relative Humidity Reproduced From T‐PARCII and Himawari‐8 Satellite Imagery Using Dynamical Initialization and Ocean‐Coupled Model: A Case Study of Typhoon Lan (2017)
Effects of the Assimilation of Relative Humidity Reproduced From T‐PARCII and Himawari‐8 Satellite Imagery Using Dynamical Initialization and Ocean‐Coupled Model: A Case Study of Typhoon Lan (2017)
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DOI：
10.1029/2020jd034516
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发表时间：
2021-08
期刊：
影响因子：
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通讯作者：
Jae‐Deok Lee;Doo‐Sun R. Park;Kosuke Ito;Chun‐Chieh Wu
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文献类型：
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作者：
Jae‐Deok Lee;Doo‐Sun R. Park;Kosuke Ito;Chun‐Chieh Wu
本文使用天气研究和预报模式研究了从热带气旋-太平洋亚洲强度估计/预报改进研究活动（T-PARCII）活动的投下式探空仪数据和Himawari-8卫星数据中复制的相对湿度（RH）同化对台风Lan（2017）模拟的影响。横向边界和初始条件由全球预报系统（GFS）的预报数据获得。为了评估热带气旋（TC）的预报性能，进行了4个不同的试验，包括初始涡、同化再生产的RH（ARH）和海洋模式（OCEAN，三维Price‐Weller‐Pinkel上层海洋环流模式）激活：GFS试验和动力学初始化（DI）试验，分别为DI、DI‐OCEAN和DI‐ARH‐OCEAN。登陆前，即36小时内，所有路径预报误差均小于100公里。与GFS实验相比，DI相关实验中的TC强度预报（如最低海平面气压和最大地面风速）略有改善。特别是DI-ARH-OCEAN实验，证明了TC预报和对流区域的改进。海洋耦合实验在TC的右后象限产生了显着的海面温度冷却，形成了一个稳定的边界层，可以抑制对流活动，特别是在对流层低层。这些结果支持了ARH方法与原始DI方法相比，可以改善初始条件，从而使TC预报更加准确。此外，它可能会认为定期的飞机监视的必要性和紧迫性，在西北太平洋地区的TC。
Effects of the assimilation of relative humidity (RH) reproduced from dropsonde data from the Tropical cyclones‐Pacific Asian Research Campaign for Improvement of Intensity estimations/forecasts (T‐PARCII) campaign and Himawari‐8 satellite data on the simulation of Typhoon Lan (2017) were investigated herein using a weather research and forecasting model. The lateral boundary and initial conditions were obtained from Global Forecast System (GFS) forecast data. Four experiments varying from the initial vortex, assimilation of the reproduced RH (ARH), and ocean model (OCEAN, three‐dimensional Price‐Weller‐Pinkel upper‐ocean circulation model) activation were conducted for 42 h to evaluate tropical cyclone (TC) forecast performance: the GFS experiment and dynamical initialization (DI) experiments such as DI, DI‐OCEAN, and DI‐ARH‐OCEAN, respectively. All track forecast errors were less than 100 km until landfall, that is, up to 36 h. TC intensity forecasts such as the minimum sea‐level pressure and maximum surface wind speed were slightly improved in DI‐related experiments compared to the GFS experiment. The DI‐ARH‐OCEAN experiment, in particular, demonstrated improvements in both TC forecasts and convective areas. The ocean‐coupled experiments yielded significant sea surface temperature cooling in the rear‐right quadrant of TC, forming a stable boundary layer that could suppress the convective activity, particularly in the lower troposphere. These findings support that compared to the original DI method, ARH could improve initial conditions, resulting in more accurate TC forecasts. Furthermore, it may argue the necessity and urgency of regular aircraft surveillance of TCs in the western North Pacific area.