Significant Aerosol Influence on the Recent Decadal Decrease in Tropical Cyclone Activity Over the Western North Pacific

Chiharu Takahashi, Masahiro Watanabe, Masato Mori

Research output: Contribution to journalArticlepeer-review

Abstract

Over the past two decades, the number of tropical cyclones (TCs) has decreased markedly in the southeastern part of the western North Pacific (WNP) as a component of the interdecadal variation. This decrease has partially been explained by an internal low-frequency variability of sea surface temperature (SST) in the Pacific, but influences of external forcing remain unclear. Here we show that past changes in sulfate aerosol emissions contributed approximately 60% of the observed decreasing trends in TC genesis frequency in the southeastern WNP for 1992–2011, using multiple simulations by a global climate model. This decrease was mainly attributed to the increased vertical wind shear and decreased low-level vorticity, associated with a trans-basin multidecadal SST change driven by aerosol forcing. The near-future projection shows that the aerosol forcing still has some potential influence on decadal TC change, but the projected decreasing frequency is mainly due to increasing greenhouse gases forcing.

Original languageEnglish
Pages (from-to)9496-9504
Number of pages9
JournalGeophysical Research Letters
Volume44
Issue number18
DOIs
Publication statusPublished - Sep 28 2017
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Earth and Planetary Sciences(all)

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