After a tropical storm makes landfall, its vortex interacts with the surrounding environment and the underlying surface. It is expected that diurnal variation over land will affect storm structures. However, this has not yet been explored in previous studies. In this paper, numerical simulation of postlandfall Tropical Storm Bill (2015) is conducted using a research version of the NCEP Hurricane Weather Research and Forecasting (HWRF) model. Results indicate that during the storm's interaction with midlatitude westerlies over the Great Plains, the simulated storm with the SLAB land‐surface scheme is stronger, with faster eastward movement and attenuation, and more asymmetric structures than that with the NOAH land‐surface scheme. More symmetric structures correspond with a slower weakening and slower eastward movement of the storm over land. Further diagnoses suggest an obvious response of the storm's asymmetric structures to diurnal effects over land. Surface diabatic heating in the storm environment is important for the storm's symmetric structures and intensity over land. Specifically, during the transition from nighttime to daytime, the evident strengthening of convective instability, atmospheric baroclinicity, and the lateral advection of high air in the storm environment, associated with the rapid increase in surface diabatic heating, are conducive to the development of vertical vorticity and storm‐relative helicity, thus contributing to the maintenance of the storm's symmetric structures and intensity after landfall.

中文翻译：

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登陆后热带风暴非对称结构的地表昼夜效应

热带风暴登陆后，其涡旋与周围环境和下层表面相互作用。预计陆地上的日变化会影响风暴结构。但是，在以前的研究中尚未对此进行探讨。在本文中，使用NCEP飓风天气研究和预报（HWRF）模型的研究版本进行了登陆后热带风暴法案（2015）的数值模拟。结果表明，在风暴与大平原中纬度西风相互作用期间，与NOAH地面方案相比，使用SLAB地表方案的模拟风暴更强，向东移动和衰减更快，结构更不对称。更加对称的结构对应于风暴在陆地上的减弱和减弱的东移。进一步的诊断表明，风暴的不对称结构对陆地上的昼夜效应有明显的响应。风暴环境中的表面绝热加热对于风暴的对称结构和陆地上的强度非常重要。具体而言，在从夜间到白天的过渡过程中，对流不稳定性，大气斜度和高纬向横向对流的明显增强 风暴环境中的空气与地表非绝热加热的迅速增加有关，有利于垂直涡度和风暴相对螺旋度的发展，从而有助于保持登陆后风暴的对称结构和强度。