![]() Based on the simulation of fog over the YS through the WRF model, Yang and Gao (2016) reported that increasing the vertical resolution could significantly improve the ability to forecast the horizontal fog area. (2014) carried out a sensitivity study on the parameterization schemes of the Weather Research and Forecasting (WRF) model and found that the best combination of the boundary layer scheme and the microphysical scheme comprises the Yonsei University (YSU) scheme and the Purdue Lin scheme, respectively. Focusing on ten cases of sea fog over the Yellow Sea (YS) in spring, Lu et al. Mesoscale models have been used to simulate the formation of sea fog in China since the turn of the century, and the corresponding mechanisms have been investigated ( Fu et al., 2004 Fu et al., 2006 Fu et al., 2008 Wang et al., 2012 Cheng et al., 2013 Huang et al., 2015 Huang et al., 2019). In some early attempts to numerically simulate sea fog, many scholars employed mesoscale forecasting models ( Ballard et al., 1991 Golding, 1993 Nakanishi, 2000 Pagowski et al., 2004 Koračin et al., 2005). In particular, one of the most important mechanisms responsible for the formation of sea fog is the condensation caused by the cooling of warm and humid air advecting to the cold sea surface. ![]() The formation and development of sea fog are affected by a series of dynamic and thermodynamic processes, such as synoptic circulations, air-sea heat and water vapour exchanges, boundary layer turbulence and entrainment, and long-wave and shortwave radiation. However, as a weather phenomenon influenced by a weak pressure field, sea fog is difficult to be numerically predicted. If the occurrence, duration, extent of influence and concentration of sea fog could be accurately predicted by an operational department, early warnings could be provided, and thus, corresponding emergency measures could be taken to reduce and avoid losses. The offshore waters of China are characterized by one of the highest frequencies of sea fog occurrence worldwide here, this phenomenon arises due to the strong sea temperature gradient and poses serious hazards to the economic development and social security of coastal China. In recent years, the casualties and property losses caused by sea fog have gradually approached those caused by extreme weather events, such as typhoons and tornadoes ( Gultepe et al., 2007). Sea fog is a phenomenon in which water vapour condenses in the lower atmosphere over the sea (including shores and islands) under the influence of the ocean ( Wang, 1983). With the above improvements, the equitable threat score (ETS) for the hindcasting of eleven sea fog cases in the spring of 2018 increases by 61%, mainly due to the increase in the correctly forecasted fog area. By increasing the number of vertical layers of the model to 68 and reducing the height of the bottom layer to approximately 10 m, the model presents a better performance in simulating the rapid formation and dissipation of sea fog. An analysis of the performances of two boundary layer parameterization schemes (the Yonsei University scheme and the Medium-Range Forecast scheme) in characterizing turbulent heat exchange reveals that the former can more accurately reflect offshore turbulence and forecast the fog area. The new SST dataset is capable of representing the key points in the area, including the low coastal SST related to upwelling, the intrusion of the Yellow Sea (YS) Warm Current, and the ocean front between the YS and the East China Sea. Instead of the sea surface temperature (SST) from the Global Forecast System (GFS) model, more accurate daily SST data reflecting the daily SST variation are used as the boundary condition. 5Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information Science and Technology, Nanjing, Chinaīased on the operational version of the China Meteorological Administration Typhoon Model (CMA-TYM, formerly known as GRAPES_TYM), a series of numerical tests are conducted by optimizing the boundary layer parameterization scheme, vertical resolution, and boundary conditions. ![]()
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |