Analysis of More Tropical Cyclone Genesis over the Western North Pacific in 2016

摘要

Tropical cyclone (TC) is the most catastrophic weather system characterized by strong winds and heavy rains, and is therefore the main research object of tropical meteorology. Based on National Oceanic and Atmospheric Administration (NOAA) Sea Surface Temperature (SST), Outgoing Long wave Radiation (OLR) and National Centers for Environmental Prediction (NCEP) monthly reanalysis data and Regional Specialized Meteorological Center (RSMC) Tokyo best track data and China Meteorological Administration (CMA) tropical cyclone during 1979-2016, we analyze the feathers of tropical cyclones and causes of more tropical cyclones (TCs) over the western north Pacific(including the South China Sea) (WNP) in 2016. The results show that compared the number of tropical cyclone genesis was higher, the originated time was later and concentrated in autumn, the region of more cyclones formed in north and east, and the number of landing TCs was higher. Negative sea surface temperature anomaly in the equatorial eastern Pacific and a westward deviation of the ascending branch of Walker circulation can strengthen the intensity of convection activity based on an existing lead-lag correlation during the period of TC activity (from August to September).The West Pacific subtropical high (WPSH) was exceptionally stronger than in other years and its west ridge point appreciably stretched westward and northward from August to September in 2016, which is favorable to TC genesis. At the same time , ω positive anomaly located in northward which was favorable for more TC genesis in WNP. In addition, the anomalous distribution of environmental factors such as low vorticity, OLR and vertical wind shear may also be the cause of the formation of tropical cyclones in the West North Pacific in 2016.