Characteristics of Tropical Cyclogenesis over the Western North Pacific in 2007

This study found that tropical cyclones (TCs) formed for fall in 2007 over the western North Pacific were distributed in high-latitudes comparing to 56-year (1951-2006) climatological mean. The frequency and latitude of TC genesis became higher than 56-year climatological mean from September onward in 2007 and all the TCs that formed to the north of 20$^{\circ}$N was also distributed after September in 2007. These characteristics of TC genesis for fall in 2007 could be confirmed through analyzing various variables, such as a large-scale atmospheric circulation, outgoing longwave radiation (OLR), vertical zonal wind shear, and sea surface temperature (SST). On the other hand, a frequency of the TC that occurred to the north of 200N showed a clear interdecadal variation and its decreasing trend was distinctive in recent years. Its intensity was also weaker that TCs that did to the south of 20$^{\circ}$N. However, a latitude of TC genesis showed an increasing trend until recent years, whose variation was consistent with trend that through a SST analysis, warm SST went north in recent years.

2007년 북서태평양에서의 열대저기압 발생 특징