Acta Oceanologica Sinica

, Volume 31, Issue 1, pp 51–58 | Cite as

Upper ocean responses to category 5 typhoon Megi in the western north Pacific

  • Xiaoyan Chen
  • Delu Pan
  • Xianqiang He
  • Yan Bai
  • Difeng Wang
Article

Abstract

Category 5 typhoon Megi was the most intense typhoon in 2010 of the world. It lingered in the South China Sea (SCS) for 5 d and caused a significant phytoplankton bloom detected by the satellite image. In this study, the authors investigated the ocean biological and physical responses to typhoon Megi by using chlorophyll-a (chl-a) concentration, sea surface temperature (SST), sea surface height anomaly (SSHA), sea surface wind measurements derived from different satellites and in situ data. The chl-a concentration (>3 mg/m3) increased thirty times in the SCS after the typhoon passage in comparison with the mean level of October averaged from 2002 to 2009. With the relationship of wind stress curl and upwelling, the authors found that the speed of upwelling was over ten times during typhoon than pre-typhoon period. Moreover, the mixed layer deepened about 20 m. These reveal that the enhancement of chl-a concentration was triggered by strong vertical mixing and upwelling. Along the track of typhoon, the maximum sea surface cooling (6–8°C) took place in the SCS where the moving speed of typhoon was only 1.4–2.8 m/s and the mixed layer depth was about 20 m in pre-typhoon period. However, the SST drop at the east of the Philippines is only 1–2°C where the translation speed of typhoon was 5.5–6.9 m/s and the mixed layer depth was about 40 m in pre-typhoon period. So the extent of the SST drop was probably due to the moving speed of typhoon and the depth of the mixed layer. In addition, the region with the largest decline of the sea surface height anomaly can indicate the location where the maximum cooling occurs.

Key words

sea surface temperature chlorophyll-a concentration sea surface height anomaly upwelling typhoon Megi ocean remote sensing 

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References

  1. Babin S M, Carton J A, Dickey T D, et al. 2004. Satellite evidence of hurricane-induced phytoplankton blooms in an oceanic desert. Journal of Geophysical Research, 109: C03043CrossRefGoogle Scholar
  2. Cione J J, Uhlhorn E W. 2003. Sea surface temperature variability in hurricanes: Implications with respect to intensity change. Monthly Weather Review, 131: 1783–1796CrossRefGoogle Scholar
  3. de Boyer Montégut C, Madec G, Fischer A S, et al. 2004. Mixed layer depth over the global ocean: an examination of profile data and a profile-based climatology. Journal of Geophysical Research, 109: C12003CrossRefGoogle Scholar
  4. Enriquez A G, Friehe C A. 1995. Effects of wind stress and wind stress curl variability on coastal upwelling. Journal of Physical Oceanography, 25(7): 1651–1671CrossRefGoogle Scholar
  5. Gao Shan, Wang Hui, Liu Guimei, et al. 2010. The statistical estimation of the vertical distribution of chlorophyll a concentration in the South China Sea. Acta Oceanologica Sinica (in Chinese), 32(4): 168–176Google Scholar
  6. Lin I, Liu W, Wu C, et al. 2003. New evidence for enhanced ocean primary production triggered by tropical cyclone. Geophysical Research Letters, 30(13): 1718CrossRefGoogle Scholar
  7. Lin I, Wu C, Pun I, et al. 2008. Upper-ocean thermal structure and the western North Pacific category 5 typhoons: Part I. Ocean features and the category 5 typhoons’ intensification. Monthly Weather Review, 136: 3288–3306CrossRefGoogle Scholar
  8. Price J F. 1981. Upper ocean response to a hurricane. Journal of Physical Oceanography, 11(2): 153–175CrossRefGoogle Scholar
  9. Sakaida F, Kawamura H, Toba Y. 1998. Sea surface cooling caused by typhoons in the Tohoku Area in August 1989. Journal of Geophysical Research, 103(C1): 1053–1065CrossRefGoogle Scholar
  10. Siswanto E, Ishizaka J, Morimoto A, et al. 2008. Ocean physical and biogeochemical responses to the passage of Typhoon Meari in the East China Sea observed from Argo float and multiplatform satellites. Geophysical Research Letters, 35(15): L15604CrossRefGoogle Scholar
  11. Siswanto E, Morimoto A, Kojima S. 2009. Enhancement of phytoplankton primary productivity in the southern East China Sea following episodic typhoon passage. Geophysical Research Letters, 36(11): L11603CrossRefGoogle Scholar
  12. Stramma L, Cornillon P, Price J F. 1986. Satellite observations of sea surface cooling by hurricanes. Journal of Geophysical Research, 91(C4): 5031–5035CrossRefGoogle Scholar
  13. Takahashi M, Hori T. 1984. Abundance of picophytoplankton in the subsurface chlorophyll maximum layer in subtropical and tropical waters. Marine Biology, 79: 177–186CrossRefGoogle Scholar
  14. Tsai Y, Chern C S, Wang J. 2008. Typhoon induced upper ocean cooling off northeastern Taiwan. Geophysical Research Letters, 35(14): L14605CrossRefGoogle Scholar
  15. Yin Xiaobin, Wang Zhenzhan, Liu Yuguang, et al. 2007. Ocean response to Typhoon Ketsana traveling over the northwest Pacific and a numerical model approach. Geophysical Research Letters, 34(21): L21606CrossRefGoogle Scholar
  16. Zhao Hui, Qi Yiquan, Wang Dongxiao, et al. 2005. Study on the features of chlorophyll-a derived from Sea-WiFS in the South China Sea. Acta Oceanologica Sinica (in Chinese), 27(4): 45–52Google Scholar
  17. Zhao Hui, Tang Danling, Wang Dongxiao. 2009. Phytoplankton blooms near the Pearl River Estuary induced by Typhoon Nuri. Journal of Geophysical Research, 114(C12): C12027CrossRefGoogle Scholar
  18. Zheng Z W, Ho C R, Zheng Q, et al. 2010. Effects of preexisting cyclonic eddies on upper ocean responses to Category 5 typhoons in the western North Pacific. Journal of Geophysical Research, 115(C9): C09013CrossRefGoogle Scholar

Copyright information

© The Chinese Society of Oceanography and Springer-Verlag Berlin Heidelberg 2012

Authors and Affiliations

  • Xiaoyan Chen
    • 1
    • 2
  • Delu Pan
    • 1
    • 2
  • Xianqiang He
    • 1
    • 2
  • Yan Bai
    • 2
  • Difeng Wang
    • 2
  1. 1.Department of Earth SciencesZhejiang UniversityHangzhouChina
  2. 2.State Key Laboratory of Satellite Ocean Environment Dynamics, Second Institute of OceanographyState Oceanic AdministrationHangzhouChina

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