Interannual variations of intense typhoon activity

Johnny C. L. Chan

doi:10.1111/j.1600-0870.2007.00241.x

Interannual variations of intense typhoon activity

Tellus

Volume 59 (2007): Issue 4

By: Johnny C. L. Chan

Open Access

|Jan 2007

Abstract

This study attempts to determine the possible causes of the interannual variations of intense tropical cyclones (TCs, or typhoons) in the western North Pacific (WNP, defined here as the region 0–40◦N, 120–180◦E). It is found that such variations cannot be explained by those of sea-surface temperature averaged over the same region. Rather, in years with a high frequency of occurrence of intense typhoons (inferred from high values of accumulated cyclone energy, or ACE), both the dynamic and thermodynamic conditions in the atmosphere, especially in the southeastern part of the WNP, are favourable for the formation of TCs. On the other hand, these conditions are not conducive for TC formation in years with small number of intense typhoons (low values of ACE). The temporal coefficients of the empirical orthogonal functions of the relative vorticity anomalies in the lower troposphere, the vertical zonal shear and the moist static energy correlate very well with ACE. The ACE is also significantly correlated with the Nino3.4 SST anomalies. It is concluded that the interannual variations of intense typhoons in the WNP are likely caused to a large extent by changes in the planetary-scale atmospheric circulation and thermodynamic structure associated with the El Ni˜no phenomenon.

References

Bell , G. D. , Halpert , M. S. , Schnell , R. C. , Higgins , R. W. , Lawrimore , J. and co-authors. 2000. Climate assessment for 1999. Bull. Amer Meteor Soc . 81 , S1-550 .
Search in Google Scholar Back to article
Chan , J. C. L. and Liu , K. S. 2004 . Global warming and western North Pacific typhoon activity from an observational perspective . J. Climate 17 , 4590 – 4602 .
Search in Google Scholar Back to article
Emanuel , K. A. 2005 . Increasing destructiveness of tropical cyclones over the past 30 years . Nature 436 , 686 – 688 .
Search in Google Scholar Back to article
Evans , J. L. 1993 . Sensitivity of tropical cyclone intensity to sea surface temperature . J. Climate 6 , 1133 – 1140 .
Search in Google Scholar Back to article
Gray , W. M. 1979 . Hurricanes: Their formation, structure, and likely role in the tropical circulation. In: Meteorology over the Tropical Oceans (ed. D. B. Shaw ). Roy. Meteor. Soc., London, UK, 155 - 218 .
Search in Google Scholar Back to article
Kerr , R. A. 2006 . A tempestuous birth for hurricane climatology . Science 312 , 676 – 678 .
Search in Google Scholar Back to article
Knaff , J. A. and Sampson , C. R. 2006 . Reanalysis of west Pacific tropical cyclone maximum intensity 1966-1987. 27th Conf Hurricanes and Trop. Meteor, Amer. Meteor. Soc., Monterey, CA, USA, 24-28 Apr. [Extended abstract on CD-ROM]
Search in Google Scholar Back to article
Knaff , J. A. and Zehr , R. M. 2007 . Reexamination of tropical cyclone wind-pressure relationships . Wea. Forecast . 22 , 71 – 88 .
Search in Google Scholar Back to article
Michaels , P. J. , Knappenberger , P. C. and Davis , R. E. 2006 . Sea-surface temperatures and tropical cyclones in the Atlantic basin. Geophys. Res. Lett . 33 , L09708 , doi: 10.29/2006GL025757 .
Open DOI Search in Google Scholar Back to article
North , G. R. , Bell , T. L. , Cahalan , R. F. and Moeng , F. J. 1982 . Sampling errors in the estimation of empirical orthogonal functions. Mon. Wea. Re v . 110 , 699 – 706 .
Search in Google Scholar Back to article
Wang , B. and Chan , J. C. L. 2002 . How strong ENSO events affect tropical storm activity over the western North Pacific . J. Climate 15 , 1643 – 1658 .
Search in Google Scholar Back to article
Webster , P. J. , Holland , G. J. , Curry , J. A. and Chang , H.-R. 2005 . Changes in tropical cyclone number, duration, and intensity in a warming environment . Science 309 , 1844– 1846 .
Search in Google Scholar Back to article