Changes in Tropical Cyclone Rainfall in China

Abstract

The torrential-rainfall-associated tropical cyclone (TC) activity often causes flood disasters in China. Moreover, studies suggest that TC-related rainfall rates are likely to increase in a warmer climate. Using daily precipitation observations at 514 meteorological stations during 1965̶2009, this study investigates the primary features of TC rainfall in China, with a particular focus on the contribution of TC rainfall to the changes in the precipitation climate and the average rainfall per TC.TC rainfall mainly affected eastern and southeastern China, accounting for more than 10% of the summer rainfall in South and Southeast China. TC rainfall trended upward in the lower reach of the Yangtze River and Southeast China, contributing to the "wetting in the south and drying in the north" pattern by enhancing the rainfall in Southeast China. This study suggests that the average rainfall per TC has significantly increased in Southeast China during 1965̶2009. In the peak season (July̶September), all significant changes are upward trends that occur south of the Yangtze River east of 110°E. This study finds that the increasing rainfall per TC was not accompanied with the enhanced TC intensity. In addition, no significant trend can be found in the translation speed of TCs that affected China during 1965̶2009, suggesting that the increasing TC rainfall per TC in China was not due to the slowdown of TC movement.

On the relationship between ENSO and tropical cyclones in the western North Pacific during the boreal summer

“…The western North Pacific (WNP) is one of the most active ocean basins and experiences about 27 TCs each year, accounting for almost one-third of the world's annual TC counts (Chan 2005). These TCs often lead to substantial loss of life and property damage to China and adjacent countries (Zhang et al 2009(Zhang et al , 2013. A better understanding of the variability of WNP TC activity and the associated physical mechanisms therefore has a profound socio-economic impact as well as scientific significance.…”

The relationship of frequent tropical cyclone activities over the western North Pacific and hot summer days in central-eastern China

“…One good example is that TC-induced precipitation accounts for a large proportion of the total precipitation in most areas of southeastern China (Ren et al 2002) and makes influence on the spatiotemporal variations in typhoon season rainfall in south China (Lee et al 2010;Chen et al 2012). In the coastal region of southeastern China, it can be more than 500 mm per year, which accounts for 20∼40% of the total annual precipitation there (Ren et al 2006;Zhang et al 2013). Those imply possible fewer hot days in southeastern China in the years when more TCs form over the WNP.…”

Greater flood risks in response to slowdown of tropical cyclones over the coast of China

“…On the other hand, some devastating TCs in recent years were characterized with longer passage time (i.e., lower translation speed) through a region, resulting in greater rainfall totals. Hurricane Harvey stalled over Texas on [25][26][27][28][29][30] August 2017, leading to unprecedented flooding and severe damages with a 2,000-y local TC rainfall total (3,13,14). Super Typhoon Morakot, the deadliest typhoon in Taiwan in the recorded history, lingered over Taiwan for over 30 h on 8-11 August 2009 and brought about a record-breaking rainfall total of over 3,000 mm (4,6).…”