dc.description.abstract | In our research, a vortex initialization scheme developed by Nguyen and Chen (2011, 2014), hereafter referred as NC scheme, to construct better tropical cyclone structure at the model initial conditions using WRF through a series of 1-h integrations is used. The basic assumptions are: 1) at the model initial time, the TC structure and intensity are related to environmental conditions; 2) the TC environment does not change drastically in the short period (~1 h).
We choose the case of typhoon Soudelor (2015) due to the large radius of the maximum wind speed for examining the performance of the NC scheme. This study has focused in three separate parts including impacts of the NC scheme on the open ocean, the initialization process using the NC scheme under the influence of terrains, and the impacts of microphysical process on TC initialization. The results show that the initial intensity, horizontal and vertical structure of TC Soudelor in the model are improved after using the NC scheme. Furthermore, when the TC is close to terrain, removing terrains is more effective than including the terrains during the initial spin-up process(NCNT), and the result is better than the initial state with terrain. Finally, different microphysics schemes are employed during the initialization. It is showed that the wind field close to surface with warm cloud process are stronger than the wind field with ice process included, resulting in stronger outflow and bringing more precipitation particles to the outer core increasing the radial extent of TC. The result could be corresponded to the distribution of the maximum reflectivity, and verified by the explanation proposed by Fovell et al. (2016). | en_US |