Intensification of landfalling typhoons over the northwest Pacific since the late 1970s

Abstract

Intensity changes in landfalling typhoons are of great concern to East and Southeast Asian countries 1 . Regional changes in typhoon intensity, however, are poorly known owing to inconsistencies among di erent data sets 2-8 . Here, we apply cluster analysis to bias-corrected data and show that, over the past 37 years, typhoons that strike East and Southeast Asia have intensified by 12-15%, with the proportion of storms of categories 4 and 5 having doubled or even tripled. In contrast, typhoons that stay over the open ocean have experienced only modest changes. These regional changes are consistent between operational data sets. To identify the physical mechanisms, we decompose intensity changes into contributions from intensification rate and intensification duration. We find that the increased intensity of landfalling typhoons is due to strengthened intensification rates, which in turn are tied to locally enhanced ocean surface warming on the rim of East and Southeast Asia. The projected ocean surface warming pattern under increasing greenhouse gas forcing suggests that typhoons striking eastern mainland China, Taiwan, Korea and Japan will intensify further. Given disproportionate damages by intense typhoons 1 , this represents a heightened threat to people and properties in the region.Tropical cyclones (TCs) cause devastating losses of life and property, and have major social and economic impacts around the world 1 . Given that nearly all the damage is associated with TC landfalls, and that the population of coastal areas is growing and sea level is rising, detection, attribution and prediction of regional changes in TC activity (especially intensity and frequency) are among the top priorities of TC research 9,10 . For the northwest Pacific, where TCs are most active and threaten a large population of East and Southeast Asia, progress in studying regional changes in TC intensity has been hindered by a lack of consensus on intensity changes among different TC data sets 2-8 . Particularly, under debate are historical changes in the annual counts of category 4-5 typhoons: the Joint Typhoon Warming Center (JTWC) and the Japan Meteorological Agency (JMA) TC data-the two most widely used data sets in typhoon research-show contradictory trends for the period starting from 1977 2,3,6,7 .The discrepancies in the TC intensity estimated independently by the two operational agencies can be reconciled by considering changes in the JMA methodology (see Methods). The adjusted JMA and JTWC data sets consistently show that the annual number of category 4-5 typhoons has increased by more than two over the past 38 years (from less than five per year to around seven per year), and the correlation coefficient between the two time series rises from 0.09 to 0.87 after the adjustment (Fig. 1a). Strikingly, the proportion of these intense typhoons to all typhoons has more than doubled, and the annual mean typhoon lifetime peak

Tropical cyclone fullness: A new concept for interpreting storm intensity

“…TC intensity, which is a measure of the near-center peak wind speed, has long been assumed to be the dominant factor in determining TC destructiveness (measured as the potential dissipation index and accumulated cyclone energy) [Camargo and Sobel, 2005;Emanuel, 2005]. Thus, the destructiveness of TCs is projected to increase [Knutson and Tuleya, 2004;Emanuel, 2005;Elsner et al, 2008;Bender et al, 2010;Knutson et al, 2010;Mendelsohn et al, 2012;Mei and Xie, 2016]. Thus, the destructiveness of TCs is projected to increase [Knutson and Tuleya, 2004;Emanuel, 2005;Elsner et al, 2008;Bender et al, 2010;Knutson et al, 2010;Mendelsohn et al, 2012;Mei and Xie, 2016].…”

Climatological Relationship between Warm Season Atmospheric Rivers and Heavy Rainfall over East Asia

“…Moreover, the rainbearing East Asian summer monsoon (e.g., Ninomiya and Murakami 1987;Tao and Chen 1987;Ninomiya and Akiyama 1992;Sampe and Xie 2010) exhibits substantial seasonal-interannual variability because of the influence of both tropical forcing (e.g., the El Niño Southern Oscillation; ENSO) and extratropical atmospheric circulation (e.g., mid-latitude atmospheric teleconnections; Wu and Wang 2002;Ding et al 2011;Kosaka et al 2012;He et al 2017;and references therein). In addition to typhoons from the northwestern Pacific (e.g., Mei et al 2015;Mei and Xie 2016), a quasi-stationary Meiyu-Baiu rainband that extends from southeast China to Japan from June to mid-July is critically important for water resources and natural disasters in the regions.…”

“…Moreover, the rainbearing East Asian summer monsoon (e.g., Ninomiya and Murakami 1987; Tao and Chen 1987;Ninomiya and Akiyama 1992; Sampe and Xie 2010) exhibits substantial seasonal-interannual variability because of the influence of both tropical forcing (e.g., the El Niño Southern Oscillation; ENSO) and extratropical atmospheric circulation (e.g., mid-latitude atmospheric teleconnections; Wu and Wang 2002;Ding et al 2011;Kosaka et al 2012; He et al 2017; and references therein). In addition to typhoons from the northwestern Pacific (e.g., Mei et al 2015;Mei and Xie 2016), a quasi-stationary Meiyu-Baiu rainband that extends from southeast China to Japan from June to mid-July is critically important for water resources and natural disasters in the regions.Tropical climate variability, such as ENSO, strongly affects the interannual variability of the East Asian summer monsoon through the tropical western North Pacific (TWNP) anticyclone and references therein). K17 found that the interannual variability of summertime AR occurrence over the northwestern Pacific is largely controlled by the preceding-winter ENSO through the Indo-western Pacific ocean capacitor (IPOC) effect (e.g., Xie et al 2009Xie et al , 2016.…”

Requirements for Sustainable Housing Design

“…It is virtually certain that intense tropical cyclone activity has increased in the North Atlantic, since 1970 [3]. Similarly, according to a latest study, typhoons that strike East and Southeast Asia have intensiied by 12-15% since the late 1970s [6].…”