• Basher, R. E., and X. Zeng, 1995: Tropical cyclones in the southwest Pacific: Spatial patterns and relationships to Southern Oscillation and sea surface temperature. J. Climate, 8 , 12491260.

    • Search Google Scholar
    • Export Citation
  • Bister, M., and K. A. Emanuel, 1998: Dissipative heating and hurricane intensity. Meteor. Atmos. Phys., 52 , 233240.

  • Bister, M., and K. A. Emanuel, 2002a: Low frequency variability of tropical cyclone potential intensity. 1. Interannual to interdecadal variability. J. Geophys. Res., 107 .4801, doi:10.1029/2001JD000776.

    • Search Google Scholar
    • Export Citation
  • Bister, M., and K. A. Emanuel, 2002b: Low frequency variability of tropical cyclone potential intensity. 2. Climatology for 1982–1995. J. Geophys. Res., 107 .4621, doi:10.1029/2001JD000780.

    • Search Google Scholar
    • Export Citation
  • Bove, M. C., J. B. Elsner, C. W. Landsea, X. Niu, and J. O’Brien, 1998: Effect of El Niño on U.S. landfalling hurricanes, revisited. Bull. Amer. Meteor. Soc., 79 , 24772482.

    • Search Google Scholar
    • Export Citation
  • Camargo, S. J., and A. H. Sobel, 2005: Western North Pacific tropical cyclone intensity and ENSO. J. Climate, 18 , 29963006.

  • Camargo, S. J., A. W. Robertson, S. J. Gaffney, P. Smyth, and M. Ghil, 2007: Cluster analysis of typhoon tracks. Part II: Large-scale circulation and ENSO. J. Climate, 20 , 36543676.

    • Search Google Scholar
    • Export Citation
  • Chan, J. C. L., 1985: Tropical cyclone activity in the northwest Pacific in relation to the El Niño/Southern Oscillation phenomenon. Mon. Wea. Rev., 113 , 599606.

    • Search Google Scholar
    • Export Citation
  • Chan, J. C. L., 2005: Interannual and interdecadal variations of tropical cyclone activity over the western North Pacific. Meteor. Atmos. Phys., 89 , 143152.

    • Search Google Scholar
    • Export Citation
  • Chan, J. C. L., 2006: Comment on “Changes in tropical cyclone number, duration, and intensity in a warming environment.”. Science, 311 .1713, doi:10.1126/science.1121522.

    • Search Google Scholar
    • Export Citation
  • Chan, J. C. L., and K. S. Liu, 2004: Global warming and western North Pacific typhoon activity from an observational perspective. J. Climate, 17 , 45904602.

    • Search Google Scholar
    • Export Citation
  • Chauvin, F., J-F. Royer, and M. Déqué, 2006: Response of hurricane-type vortices to global warming as simulated by ARPEGE-Climat at high resolution. Climate Dyn., 27 , 377399.

    • Search Google Scholar
    • Export Citation
  • Chia, H. H., and C. F. Ropelewski, 2002: The interannual variability in the genesis location of tropical cyclones in the northwest Pacific. J. Climate, 15 , 29342944.

    • Search Google Scholar
    • Export Citation
  • Chu, P-S., 2002: Large-scale circulation features associated with decadal variations of tropical cyclone activity over the central North Pacific. J. Climate, 15 , 26782689.

    • Search Google Scholar
    • Export Citation
  • Chu, P-S., 2004: ENSO and tropical cyclone activity. Hurricanes and Typhoons, Past, Present and Future, R. J. Murnane and K.-B. Liu, Eds., Columbia University Press, 297–332.

    • Search Google Scholar
    • Export Citation
  • Chu, P-S., and J. Wang, 1997: Tropical cyclone occurrences in the vicinity of Hawaii: Are the differences between El Niño and non–El Niño years significant? J. Climate, 10 , 26832689.

    • Search Google Scholar
    • Export Citation
  • Clark, J. D., and P-S. Chu, 2002: Interannual variation of tropical cyclone activity over the Central North Pacific. J. Meteor. Soc. Japan, 80 , 403418.

    • Search Google Scholar
    • Export Citation
  • Collins, J. M., and I. M. Mason, 2000: Local environmental conditions related to seasonal tropical cyclone activity in the Northeast Pacific basin. Geophys. Res. Lett., 27 , 38813884.

    • Search Google Scholar
    • Export Citation
  • Dong, K., 1988: El Niño and tropical cyclone frequency in the Australian region and the North-western Pacific. Aust. Meteor. Mag., 36 , 219255.

    • Search Google Scholar
    • Export Citation
  • Elsner, J. B., and A. B. Kara, 1999: Hurricanes of the North Atlantic: Climate and Society. Oxford University Press, 488 pp.

  • Elsner, J. B., and K. B. Liu, 2003: Examining the ENSO-typhoon hypothesis. Climate Res., 25 , 4354.

  • Emanuel, K. A., 1988: The maximum intensity of hurricanes. J. Atmos. Sci., 45 , 11431155.

  • Emanuel, K. A., 1995: Sensitivity of tropical cyclones to surface exchange coefficients and a revised steady-state model incorporating eye dynamics. J. Atmos. Sci., 52 , 39693976.

    • Search Google Scholar
    • Export Citation
  • Emanuel, K. A., 2000: A statistical analysis of tropical cyclone intensity. Mon. Wea. Rev., 128 , 11391152.

  • Emanuel, K. A., and D. S. Nolan, 2004: Tropical cyclone activity and global climate. Preprints, 26th Conf. on Hurricanes and Tropical Meteorology, Miami, FL, Amer. Meteor. Soc., 240–241.

  • Evans, J. L., and R. J. Allan, 1992: El Niño/Southern Oscillation modification to the structure of the monsoon and tropical cyclone activity in the Australian region. Int. J. Climatol., 12 , 611623.

    • Search Google Scholar
    • Export Citation
  • Ferreira, R. N., W. H. Schubert, and J. J. Hack, 1996: Dynamical aspects of twin tropical cyclones associated with the Madden–Julian oscillation. J. Atmos. Sci., 53 , 929945.

    • Search Google Scholar
    • Export Citation
  • Goddard, L., and M. Dilley, 2005: El Niño: Catastrophe or opportunity? J. Climate, 18 , 651665.

  • Goldenberg, S. B., and L. J. Shapiro, 1996: Physical mechanisms for the association of El Niño and West African rainfall with Atlantic major hurricane activity. J. Climate, 9 , 11691187.

    • Search Google Scholar
    • Export Citation
  • Gray, W. M., 1979: Hurricanes: Their formation, structure and likely role in the tropical circulation. Meteorology over the Tropical Oceans, D. B. Shaw, Ed., Royal Meteorological Society, 155–218.

    • Search Google Scholar
    • Export Citation
  • Gray, W. M., 1984: Atlantic seasonal hurricane frequency. Part I: El Niño and 30 mb quasi-biennial oscillation influences. Mon. Wea. Rev., 112 , 16491668.

    • Search Google Scholar
    • Export Citation
  • Gray, W. M., and J. D. Sheaffer, 1991: El Niño and QBO influences on tropical cyclone activity. Teleconnections Linking Worldwide Anomalies, M. H. Glantz, R. W. Katz, and N. Nicholls, Eds., Cambridge University Press, 257–284.

    • Search Google Scholar
    • Export Citation
  • Gray, W. M., C. W. Landsea, P. W. Mielke Jr., and K. J. Berry, 1993: Predicting Atlantic basin seasonal tropical cyclone activity by 1 August. Wea. Forecasting, 8 , 7386.

    • Search Google Scholar
    • Export Citation
  • Hastings, P. A., 1990: Southern Oscillation influences on tropical cyclone activity in the Australian/South-west Pacific region. Int. J. Climatol., 10 , 291298.

    • Search Google Scholar
    • Export Citation
  • Irwin, R. P., and R. Davis, 1999: The relationship between the Southern Oscillation Index and tropical cyclone tracks in the eastern North Pacific. Geophys. Res. Lett., 26 , 22512254.

    • Search Google Scholar
    • Export Citation
  • Kalnay, E., and Coauthors, 1996: The NCEP/NCAR 40-Year Reanalysis Project. Bull. Amer. Meteor. Soc., 77 , 437471.

  • Knaff, J. A., 1997: Implications of summertime sea level pressure anomalies in the tropical Atlantic region. J. Climate, 10 , 789804.

  • Lander, M. A., 1994: An exploratory analysis of the relationship between tropical storm formation in the western North Pacific and ENSO. Mon. Wea. Rev., 122 , 636651.

    • Search Google Scholar
    • Export Citation
  • Lander, M. A., 1996: Specific tropical cyclone track types and unusual tropical cyclone motions associated with a reverse-oriented monsoon trough in the western North Pacific. Wea. Forecasting, 11 , 170186.

    • Search Google Scholar
    • Export Citation
  • Landsea, C. W., 2000: El Niño–Southern Oscillation and the seasonal predictability of tropical cyclones. El Niño: Impacts of Multiscale Variability on Natural Ecosystems and Society, H. F. Díaz and V. Markgraf, Eds., Cambridge University Press, 149–181.

    • Search Google Scholar
    • Export Citation
  • Landsea, C. W., R. A. Pielke Jr., A. M. Mestas-Nuñez, and J. A. Knaff, 1999: Atlantic basin hurricanes: Indices of climatic changes. Climatic Change, 42 , 89129.

    • Search Google Scholar
    • Export Citation
  • Livezey, R. E., and W. Y. Chen, 1983: Statistical field significance and its determination by Monte Carlo techniques. Mon. Wea. Rev., 111 , 4659.

    • Search Google Scholar
    • Export Citation
  • McDonald, R. E., D. G. Bleaken, D. R. Cresswell, V. D. Pope, and C. A. Senior, 2005: Tropical storms: Representation and diagnosis in climate models and the impacts of climate change. Climate Dyn., 25 , 1936.

    • Search Google Scholar
    • Export Citation
  • Nicholls, N., 1979: A possible method for predicting seasonal tropical cyclone activity in the Australian region. Mon. Wea. Rev., 107 , 12211224.

    • Search Google Scholar
    • Export Citation
  • Nicholls, N., 1985: Predictability of interannual variations of Australian seasonal tropical cyclone activity. Mon. Wea. Rev., 113 , 11441149.

    • Search Google Scholar
    • Export Citation
  • Nicholls, N., C. W. Landsea, and J. Gill, 1998: Recent trends in Australian region tropical cyclone activity. Meteor. Atmos. Phys., 65 , 197205.

    • Search Google Scholar
    • Export Citation
  • Pan, Y. H., and A. H. Oort, 1983: Global climate variations connected with sea surface temperature anomalies in the eastern equatorial Pacific Ocean for the 1958–73 period. Mon. Wea. Rev., 111 , 12441258.

    • Search Google Scholar
    • Export Citation
  • Pielke Jr., R. A., and C. W. Landsea, 1999: La Niña, El Niño and Atlantic hurricane damages in the United States. Bull. Amer. Meteor. Soc., 80 , 20272033.

    • Search Google Scholar
    • Export Citation
  • Revell, C., and S. Goulter, 1986: South Pacific tropical cyclones and the Southern Oscillation. Mon. Wea. Rev., 114 , 11381144.

  • Royer, J-F., F. Chauvin, B. Timbal, P. Araspin, and D. Grimal, 1998: A GCM study of the impact of greenhouse gas increase on the frequency of occurrence of tropical cyclone. Climatic Change, 38 , 307343.

    • Search Google Scholar
    • Export Citation
  • Ryan, B. F., I. G. Watterson, and J. L. Evans, 1992: Tropical cyclone frequencies inferred from Gray’s yearly genesis parameter: Validation of GCM tropical climates. Geophys. Res. Lett., 19 , 18311834.

    • Search Google Scholar
    • Export Citation
  • Saunders, M. A., R. E. Chandler, C. J. Merchant, and F. P. Roberts, 2000: Atlantic hurricanes and NW Pacific typhoons: ENSO spatial impacts on occurrence and landfall. Geophys. Res. Lett., 27 , 11471150.

    • Search Google Scholar
    • Export Citation
  • Shapiro, L. J., 1987: Month-to-month variability of the Atlantic tropical circulation and its relationship to tropical storm formation. Mon. Wea. Rev., 115 , 25982614.

    • Search Google Scholar
    • Export Citation
  • Singh, O. P., T. M. A. Khan, and M. S. Rahman, 2000: Changes in the frequency of tropical cyclones over the North Indian Ocean. Meteor. Atmos. Phys., 75 , 1120.

    • Search Google Scholar
    • Export Citation
  • Sobel, A. H., and S. J. Camargo, 2005: Influence of western North Pacific tropical cyclones on their large-scale environment. J. Atmos. Sci., 62 , 33963407.

    • Search Google Scholar
    • Export Citation
  • Tang, B. H., and J. D. Neelin, 2004: ENSO influence on Atlantic hurricanes via tropospheric warming. Geophys. Res. Lett., 31 .L24204, doi:10.1029/2004GL021072.

    • Search Google Scholar
    • Export Citation
  • Wang, B., and J. C. L. Chan, 2002: How strong ENSO events affect tropical storm activity over the western North Pacific. J. Climate, 15 , 16431658.

    • Search Google Scholar
    • Export Citation
  • Watterson, I. G., J. L. Evans, and B. F. Ryan, 1995: Seasonal and interannual variability of tropical cyclogenesis: Diagnostics from large-scale fields. J. Climate, 8 , 30523066.

    • Search Google Scholar
    • Export Citation
  • Whitney, L. D., and J. Hobgood, 1997: The relationship between sea surface temperatures and maximum intensities of tropical cyclones in the eastern North Pacific Ocean. J. Climate, 10 , 29212930.

    • Search Google Scholar
    • Export Citation
  • Wu, G., and N-C. Lau, 1992: A GCM simulation of the relationship between tropical-storm formation and ENSO. Mon. Wea. Rev., 120 , 958977.

    • Search Google Scholar
    • Export Citation
  • Wu, M. C., W. L. Chang, and W. M. Leung, 2004: Impacts of El Niño–Southern Oscillation events on tropical cyclone landfalling activity in the western North Pacific. J. Climate, 17 , 14191428.

    • Search Google Scholar
    • Export Citation
All Time Past Year Past 30 Days
Abstract Views 0 0 0
Full Text Views 3065 1808 171
PDF Downloads 2188 1151 69

Use of a Genesis Potential Index to Diagnose ENSO Effects on Tropical Cyclone Genesis

Suzana J. CamargoInternational Research Institute for Climate and Society, Lamont Campus, Palisades, New York

Search for other papers by Suzana J. Camargo in
Current site
Google Scholar
PubMed
Close
,
Kerry A. EmanuelProgram in Atmospheres, Oceans, and Climate, Massachusetts Institute of Technology, Cambridge, Massachusetts

Search for other papers by Kerry A. Emanuel in
Current site
Google Scholar
PubMed
Close
, and
Adam H. SobelDepartment of Applied Physics and Applied Mathematics, and Department of Earth and Environmental Sciences, Columbia University, New York, New York

Search for other papers by Adam H. Sobel in
Current site
Google Scholar
PubMed
Close
Restricted access

Abstract

ENSO (El Niño–Southern Oscillation) has a large influence on tropical cyclone activity. The authors examine how different environmental factors contribute to this influence, using a genesis potential index developed by Emanuel and Nolan. Four factors contribute to the genesis potential index: low-level vorticity (850 hPa), relative humidity at 600 hPa, the magnitude of vertical wind shear from 850 to 200 hPa, and potential intensity (PI). Using monthly NCEP Reanalysis data in the period of 1950–2005, the genesis potential index is calculated on a latitude strip from 60°S to 60°N. Composite anomalies of the genesis potential index are produced for El Niño and La Niña years separately. These composites qualitatively replicate the observed interannual variations of the observed frequency and location of genesis in several different basins. This justifies producing composites of modified indices in which only one of the contributing factors varies, with the others set to climatology, to determine which among the factors are most important in causing interannual variations in genesis frequency. Specific factors that have more influence than others in different regions can be identified. For example, in El Niño years, relative humidity and vertical shear are important for the reduction in genesis seen in the Atlantic basin, and relative humidity and vorticity are important for the eastward shift in the mean genesis location in the western North Pacific.

Corresponding author address: Suzana Camargo, IRI—225 Monell Bldg., P.O. Box 1000, Palisades, NY 10964-8000. Email: suzana@iri.columbia.edu

Abstract

ENSO (El Niño–Southern Oscillation) has a large influence on tropical cyclone activity. The authors examine how different environmental factors contribute to this influence, using a genesis potential index developed by Emanuel and Nolan. Four factors contribute to the genesis potential index: low-level vorticity (850 hPa), relative humidity at 600 hPa, the magnitude of vertical wind shear from 850 to 200 hPa, and potential intensity (PI). Using monthly NCEP Reanalysis data in the period of 1950–2005, the genesis potential index is calculated on a latitude strip from 60°S to 60°N. Composite anomalies of the genesis potential index are produced for El Niño and La Niña years separately. These composites qualitatively replicate the observed interannual variations of the observed frequency and location of genesis in several different basins. This justifies producing composites of modified indices in which only one of the contributing factors varies, with the others set to climatology, to determine which among the factors are most important in causing interannual variations in genesis frequency. Specific factors that have more influence than others in different regions can be identified. For example, in El Niño years, relative humidity and vertical shear are important for the reduction in genesis seen in the Atlantic basin, and relative humidity and vorticity are important for the eastward shift in the mean genesis location in the western North Pacific.

Corresponding author address: Suzana Camargo, IRI—225 Monell Bldg., P.O. Box 1000, Palisades, NY 10964-8000. Email: suzana@iri.columbia.edu

Save