Regionally, although the annual PDI increases along all sections of the EAC, those near the South China coast, East China coast, Korean Peninsula and Japan islands are all statistically significant but those for the Philippines and Vietnam are not. The main cause of the RI is an increased tropical cyclone heat potential and a reduced vertical wind shear, but the sea-surface temperature is not a contributor. Indeed, the location of lifetime maximum intensity of RI TCs has also shifted to nearer the coast. Such increases result from the TC formation locations being further north and west so that if the TCs undergo RI, they are more likely to make landfall. Because of such increases, the annual power dissipation index (PDI) along the EAC also increased. In the presentation, it will be shown that along the EAC, both the number and percentage of landfalling TCs that experienced RI during their lifetime increased in the last two decades. A more important question is how many of these RI TCs make landfall in the East Asia coast (EAC), which is the objective of this study. Many studies have suggested that the number and percentage of rapidly-intensifying (RI) tropical cyclones (TCs) appear to be increasing in the western North Pacific. The authors' confidence was lower for projections of: decreased global tropical cyclone frequency and a reduction of tropical cyclone translation speed. Projections of tropical cyclone activity under a 2 degree Celsius global anthropogenic warming scenario include the following at the global-mean scale: greater storm surge inundation levels due to rising sea level (high confidence) +14% increase in tropical cyclone precipitation rates +5% increase in tropical cyclone wind speeds and +13% increase in the proportion of category 4 & 5 tropical cyclones (the latter three projections each with medium to high confidence). A few more recently published studies not assessed by the WMO team will also be discussed. They further concluded that "the balance of evidence" suggests that there are some cases where there may be detectable (unusual compared to natural variability) or attributable (to anthropogenic influence) changes emerging in observed tropical cyclone activity, even though confidence is currently low by conventional assessment standards. The majority of the author panel had low confidence that detection and attribution has been established, with one case (poleward migration of the latitude of maximum intensity in the western North Pacific) having low-to-medium confidence.
#RYO SHIHO TASKR 018 SERIES#
The assessment was published in the Bulletin of the American Meteorological Society in 20.The assessment team reviewed a series of case studies to assess whether detection and attribution of anthropogenic influence on tropical cyclones can be supported by historical observational data and other evidence.
A WMO Task Team on Tropical Cyclones and Climate Change was tasked with providing an updated assessment of the science of tropical cyclones and climate change.
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