Spatial and temporal distribution of Northwest Pacific tropical cyclone and its relationship with sea surface temperature

Abstract:

Utilizing The NOAA Daily Sea Surface Temperature Analysis data and the Joint Typhoon Warning Center (JTWC) best-track tropical cyclone (TC) data for the period 1982–2014. Spatial and temporal characteristics of northwest pacific TC activity are analyzed. The results show: (1) TC has three distinct birthplaces: Birthplace 1 (10°-22°N，110°-120°E), Birthplace 2 (8°-20°N，125°-145°E), Birthplace 3 (5°-20°N，145°-155°E), and the frequency of birthplace 2 is more than the other two; (2) The frequency of TC has an evident interannual variability; 1982-1992 and 2003-2014 was Low-frequency years, and 1993-2002 was High-frequency years. From 1982-2014, the frequency characteristics of TC showed slow increase - rapid increase - decrease. During 2000-2014, the number of TC shows a clear downward trend; (3) TC concentrates in June-Oct every year. There is the largest number of TC’s occurrence in Aug, whereas the smallest number of it in Feb. In May, Nov and Dec, the number of TC increases slowly. And from June to Oct, the frequency showed a trend of slow decline; (4) The birthplace of TC occurs with a corresponding movement of the warm pool. From Jan to Aug, the birthplace of TC with the warm pool was gradually moving toward the higher latitudes. From Sept to Dec, the birthplace of TC with the warm pool was gradually moving toward the low latitudes; (5) The birthplace of TC often appears in the sea area which was in the south of 27℃ isotherm in the center of warm pool. More than 70% of TC appears in the south of 29℃ isotherm. During Jan-Mar and Nov-Dec, TC mainly appears in the sea area between 27-29℃ isotherm, and during April-Oct, it mainly appears in the sea area between 28-30℃ isotherm. (6) Over the past 33 years, the annual change in the northwest Pacific between SST and TC has little relationship; since 2000, with the rise of SST, TC frequency shows a downward trend.