Influences of climate change on western north Pacific and north Atlantic landfalling tropical cyclones and their impacts as inferred from high-resolution model simulations
Ph.D. Associated with strong winds, extreme rainfall and storm surges, tropical cyclone (TC) is one of the most devastating natural disasters to coastal regions and can inflict huge economical and human losses. Although it has been argued that global warming is almost certain to cause more intense s...
| Other Authors: | , , |
|---|---|
| Format: | Text |
| Language: | English Chinese |
| Published: |
2019
|
| Subjects: | |
| Online Access: | https://julac.hosted.exlibrisgroup.com/primo-explore/search?query=addsrcrid,exact,991039874558903407,AND&tab=default_tab&search_scope=All&vid=CUHK&mode=advanced&lang=en_US https://repository.lib.cuhk.edu.hk/en/item/cuhk-2398946 |
| Summary: | Ph.D. Associated with strong winds, extreme rainfall and storm surges, tropical cyclone (TC) is one of the most devastating natural disasters to coastal regions and can inflict huge economical and human losses. Although it has been argued that global warming is almost certain to cause more intense storms, heavier rainfall and stronger storm surges globally, changes of these characteristics regionally are still not clear. In this study, changes in characteristics of landfalling TCs in two active basins, namely Western North Pacific (WNP) and North Atlantic (NA), are analysed under global warming conditions. Two scientific questions are addressed: (1) How will the landfalling TCs in these two basins change due to global warming? (2) If TCs are intensified, will these systems sustain longer over land, thereby having stronger influences over coastal regions? Historical change of WNP land-falling TC activities from 1970 to 2016 is first examined using different best track datasets. Observations of maximum sustainable surface wind speed at landfall (hereinafter referred to as TC landfall intensity) of intense storms (Typhoon class or stronger) indicates a marked increasing trend of ~ 2 m/s (6.7%) per decade. Superimposed onto such long-term rise are strong inter-annual variations in the TC landfall intensity, which is closely associated with the occurrence of Central Pacific (CP)-type El Niño. During CP El Niño, low-level vorticity (vertical wind shear) is enhanced (reduced) near South China Sea and WNP, thereby providing a more favorable environment for storm intensification. On the inter-decadal timescale, enhancement of landfall intensity is found to be highly related to local SST warming and weakened of vertical wind shear over the region of 10-25°N, 115-140°E, as revealed by stepwise regression analyses. In fact, the local SST has been increasing by ~ 0.1 K per decade, implying a rise of the maximum potential intensity (MPI) by 0.75 m/s per decade, or 37.5% of the observed landfall intensity intensification ... |
|---|