Tropical cyclones and heavy rainfall in Fujian Province, China

Abstract

Tropical cyclones (TCs) are historically documented along the coastline of China. They can have negative impacts on society and damages are reported annually. This paper examines to what extent TCs are responsible for heavy rain days (precipitation > 100 mm/d) in coastal Fujian Province. The average deviation of TCs making landfall in China is 25%, and they occur more reliably than TCs in the west North Pacific. A distinct typhoon season between July and September/October was detected and can be explained by low interannual variability during these months. The annual number of TCs is below average (above average) during El Niño (La Niña) years, but the intensity of TCs is higher during El Niño years. From 1960 to 2007, 41% of heavy rain days (precipitation > 100 mm/d) at all 66 weather stations in Fujian Province were triggered by TCs. The number of heavy rain days is higher during El Niño years, although the number of TCs affecting Fujian in general is higher during La Niña years. For the coastal weather stations in east Fujian, 57% (45%) of the heavy rain days are triggered by TCs during El Niño (La Niña) years. In the research area, more than 50% of annual heavy rain days can be explained by TCs, and the ratio reaches 85% in the northern part bordering Zhejiang Province. More TCs impact Fujian during La Niña years, but more TCs cause heavy precipitation days during El Niño years. The number of heavy rain days fluctuates in line with the interannual variability of TCs making landfall.