Impacts of pre-existing ocean cyclonic circulation on sea surface chlorophyll-a concentrations off northeastern Taiwan following episodic typhoon passages

Fanghua Xu, Yuan Yao, Leo Oey, Yanluan Lin

Research output: Contribution to journalArticlepeer-review

15 Scopus citations

Abstract

Off northeastern Taiwan, enhancement of sea surface chlorophyll-a (Chl-a) concentration is frequently found after typhoon passages. From 1998 to 2013, 46 typhoon events are analyzed to examine the variations in Chl-a concentration from satellite ocean color data. On average, Chl-a concentration increased by 38% after a typhoon passage. Noticeably, four remarkable Chl-a increases after typhoons coincide with pre-existing oceanic cyclones in the study area. The Chl-a increase is significantly anticorrelated (p < 0.01) with relative SSH, defined as the difference of SSH in the study area and in the surrounding area. To assess the impact of pre-existing cyclones on the upper ocean response to typhoons, we conduct a series of numerical experiments to simulate the oceanic response to Typhoon Kaemi (2006) with or without a pre-existing oceanic cyclone, and with or without strong typhoon winds. The results show that the experiment with a pre-existing oceanic cyclone produces the largest upwelling due to cyclone intensification, mainly induced by the positive wind stress curl dipole northeast of Taiwan.

Original languageEnglish
Pages (from-to)6482-6497
Number of pages16
JournalJournal of Geophysical Research: Oceans
Volume122
Issue number8
DOIs
StatePublished - Aug 2017

Keywords

  • chlorophyll
  • cyclonic eddies
  • Kuroshio
  • off northeastern Taiwan
  • typhoon

Fingerprint

Dive into the research topics of 'Impacts of pre-existing ocean cyclonic circulation on sea surface chlorophyll-a concentrations off northeastern Taiwan following episodic typhoon passages'. Together they form a unique fingerprint.

Cite this