On the Potential Causes of the Nonstationary Correlations between West African Precipitation and Atlantic Hurricane Activity

Andreas H. Fink Institute of Geophysics and Meteorology, University of Cologne, Cologne, Germany

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Jon M. Schrage Department of Atmospheric Sciences, Creighton University, Omaha, Nebraska

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Simone Kotthaus Department of Geography, King’s College London, London, United Kingdom

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Abstract

For years, various indices of seasonal West African precipitation have served as useful predictors of the overall tropical cyclone activity in the Atlantic Ocean. Since the mid-1990s, the correlation unexpectedly deteriorated. In the present study, statistical techniques are developed to describe the nonstationary nature of the correlations between annual measures of Atlantic tropical cyclone activity and three selected West African precipitation indices (namely, western Sahelian precipitation in June–September, central Sahelian precipitation in June–September, and Guinean coastal precipitation in the preceding year’s August–November period). The correlations between these parameters are found to vary over the period from 1921 to 2007 on a range of time scales. Additionally, considerable year-to-year variability in the strength of these correlations is documented by selecting subsamples of years with respect to various meteorological factors. Broadly, in years when the environment in the main development region is generally favorable for enhanced tropical cyclogenesis (e.g., when sea surface temperatures are high, when there is relatively little wind shear through the depth of the troposphere, or when the relative vorticity in the midtroposphere is anomalously high), the correlations between indices of West African monsoon precipitation and Atlantic tropical cyclone activity are considerably weaker than in years when the overall conditions in the region are less conducive. Other more remote climate parameters, such as the phase of the Southern Oscillation, are less effective at modulating the nature of these interactions.

Corresponding author address: Andreas H. Fink, Institute of Geophysics and Meteorology, University of Cologne, Kerpener Strasse 13, D-50923 Köln, Germany. Email: fink@meteo.uni-koeln.de

Abstract

For years, various indices of seasonal West African precipitation have served as useful predictors of the overall tropical cyclone activity in the Atlantic Ocean. Since the mid-1990s, the correlation unexpectedly deteriorated. In the present study, statistical techniques are developed to describe the nonstationary nature of the correlations between annual measures of Atlantic tropical cyclone activity and three selected West African precipitation indices (namely, western Sahelian precipitation in June–September, central Sahelian precipitation in June–September, and Guinean coastal precipitation in the preceding year’s August–November period). The correlations between these parameters are found to vary over the period from 1921 to 2007 on a range of time scales. Additionally, considerable year-to-year variability in the strength of these correlations is documented by selecting subsamples of years with respect to various meteorological factors. Broadly, in years when the environment in the main development region is generally favorable for enhanced tropical cyclogenesis (e.g., when sea surface temperatures are high, when there is relatively little wind shear through the depth of the troposphere, or when the relative vorticity in the midtroposphere is anomalously high), the correlations between indices of West African monsoon precipitation and Atlantic tropical cyclone activity are considerably weaker than in years when the overall conditions in the region are less conducive. Other more remote climate parameters, such as the phase of the Southern Oscillation, are less effective at modulating the nature of these interactions.

Corresponding author address: Andreas H. Fink, Institute of Geophysics and Meteorology, University of Cologne, Kerpener Strasse 13, D-50923 Köln, Germany. Email: fink@meteo.uni-koeln.de

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  • Bader, J., and M. Latif, 2003: The impact of decadal-scale Indian Ocean sea surface temperature anomalies on Sahelian rainfall and the North Atlantic Oscillation. Geophys. Res. Lett., 30 , 2169. doi:10.1029/2003GL018426.

    • Search Google Scholar
    • Export Citation
  • Bell, G. D., and Coauthors, 2000: Climate assessment for 1999. Bull. Amer. Meteor. Soc., 81 , S1S50.

  • Berry, G. J., and C. D. Thorncroft, 2005: Case study of an intense African easterly wave. Mon. Wea. Rev., 133 , 752766.

  • Bister, M., and K. Emanuel, 1998: Dissipative heating and hurricane intensity. Meteor. Atmos. Phys., 65 , 233240.

  • Carlson, T. N., and S. G. Benjamin, 1980: Radiative heating rates of Saharan dust. J. Atmos. Sci., 37 , 193213.

  • Chen, M., P. Xie, J. E. Janowiak, and P. A. Arkin, 2002: Global land precipitation: A 50-yr monthly analysis based on gauge observations. J. Hydrometeor., 3 , 249266.

    • Search Google Scholar
    • Export Citation
  • DeMott, P. J., K. Sassen, M. R. Poellot, D. Baumgardner, D. C. Rogers, S. D. Brooks, A. J. Prenni, and S. M. Kreidenweis, 2003: African dust aerosols as atmospheric ice nuclei. Geophys. Res. Lett., 30 , 17321735.

    • Search Google Scholar
    • Export Citation
  • Dunion, J. P., and C. S. Velden, 2004: The impact of the Saharan air layer on Atlantic tropical cyclone activity. Bull. Amer. Meteor. Soc., 85 , 353365.

    • Search Google Scholar
    • Export Citation
  • Emanuel, K. A., 2005: Increasing destructiveness of tropical cyclones over the past 30 years. Nature, 436 , 686688.

  • Fink, A., and P. Speth, 1997: Some potential forcing mechanisms of the year-to-year variability of the tropical convection and its intraseasonal (25–70 day) variability. Int. J. Climatol., 17 , 15131534.

    • Search Google Scholar
    • Export Citation
  • Fink, A., D. G. Vincent, P. Reiner, and P. Speth, 2004: Mean state and wave disturbances during phases I, II, and III of GATE based on ERA-40. Mon. Wea. Rev., 132 , 16611683.

    • Search Google Scholar
    • Export Citation
  • 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
  • Goldenberg, S. B., C. W. Landsea, A. M. Mestas-Nuñez, and W. M. Gray, 2001: The recent increase in Atlantic hurricane activity: Causes and implications. Science, 293 , 474479.

    • Search Google Scholar
    • Export Citation
  • Gray, W. M., and C. W. Landsea, 1992: African rainfall as a precursor of hurricane-related destruction on the U.S. East Coast. Bull. Amer. Meteor. Soc., 73 , 13521364.

    • Search Google Scholar
    • Export Citation
  • Gray, W. M., C. W. Landsea, P. W. Mielke Jr., and K. J. Berry, 1992: Predicting Atlantic basin seasonal hurricane activity 6–11 months in advance. Wea. Forecasting, 7 , 440455.

    • 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
  • Hoerling, M. P., A. Kumar, and M. Zhong, 1997: El Niño, La Niña, and the nonlinearity of their teleconnections. J. Climate, 10 , 17691786.

    • Search Google Scholar
    • Export Citation
  • Kalnay, E., and Coauthors, 1996: The NCEP/NCAR 40-Year Reanalysis Project. Bull. Amer. Meteor. Soc., 77 , 437472.

  • Kennedy, J., H. Titchner, D. Parker, Mark Beswick, J. Hardwick, and P. Thorne, 2008: Global and regional climate in 2007. Weather, 63 , 296304.

    • Search Google Scholar
    • Export Citation
  • Kistler, R., and Coauthors, 2001: The NCEP–NCAR 50-Year Reanalysis: Monthly Means CD-ROM and documentation. Bull. Amer. Meteor. Soc., 82 , 247267.

    • Search Google Scholar
    • Export Citation
  • Klotzbach, P. J., and W. M. Gray, 2003: Forecasting September Atlantic basin tropical cyclone activity. Wea. Forecasting, 18 , 11091128.

    • Search Google Scholar
    • Export Citation
  • Klotzbach, P. J., and W. M. Gray, 2004: Updated 6–11-month prediction of Atlantic basin seasonal hurricane activity. Wea. Forecasting, 19 , 917934.

    • Search Google Scholar
    • Export Citation
  • Klotzbach, P. J., and W. M. Gray, 2006: Causes of the unusually destructive 2004 Atlantic basin hurricane season. Bull. Amer. Meteor. Soc., 87 , 13251333.

    • Search Google Scholar
    • Export Citation
  • Kossin, J. P., and D. J. Vimont, 2007: A more general framework for understanding Atlantic hurricane variability and trends. Bull. Amer. Meteor. Soc., 88 , 17671781.

    • Search Google Scholar
    • Export Citation
  • Landsea, C. W., and W. M. Gray, 1992: The strong association between western Sahel monsoon rainfall and intense Atlantic hurricanes. J. Climate, 5 , 435453.

    • Search Google Scholar
    • Export Citation
  • Landsea, C. W., W. M. Gray, P. W. Mielke Jr., and K. J. Berry, 1992: Long-term variations of western Sahelian monsoon rainfall and intense U.S. landfalling hurricanes. J. Climate, 5 , 15281534.

    • Search Google Scholar
    • Export Citation
  • Landsea, C. W., W. M. Gray, P. W. Mielke Jr., and K. J. Berry, 1997: African Sahel rainfall variability and seasonal forecasting. Preprints, 13th Conf. on Hydrology, Long Beach, CA, Amer. Meteor. Soc., J40–J43.

    • Search Google Scholar
    • Export Citation
  • Landsea, C. W., G. D. Bell, W. M. Gray, and S. B. Goldenberg, 1998: The extremely active 1995 Atlantic hurricane season: Environmental conditions and verification of seasonal forecasts. Mon. Wea. Rev., 126 , 11741193.

    • 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
  • Landsea, C. W., B. A. Harper, K. Hoarau, and J. A. Knaff, 2006: Can we detect trends in extreme tropical cyclones? Science, 313 , 452454.

    • Search Google Scholar
    • Export Citation
  • Levinson, D. H., 2005: State of the climate in 2004. Bull. Amer. Meteor. Soc., 86 , S1S86.

  • Levinson, D. H., and J. H. Lawrimore, 2008: Climate assessment for 2007. Bull. Amer. Meteor. Soc., 89 , S1S179.

  • Lu, J., and T. L. Delworth, 2005: Oceanic forcing of the late 20th century Sahel drought. Geophys. Res. Lett., 32 , L22706. doi:10.1029/2005GL023316.

    • Search Google Scholar
    • Export Citation
  • Martin, J. D., and W. M. Gray, 1993: Tropical cyclone observation and forecasting with and without aircraft reconnaissance. Wea. Forecasting, 8 , 519532.

    • Search Google Scholar
    • Export Citation
  • Mendenhall, W., D. D. Wackerly, and R. L. Scheaffer, 1990: Mathematical Statistics with Applications. PWS-KENT Publishing, 540 pp.

  • Mitchell, T. D., and P. D. Jones, 2005: An improved method of constructing a database of monthly climate observations and associated high-resolution grids. Int. J. Climatol., 25 , 693712.

    • Search Google Scholar
    • Export Citation
  • Newell, R. E., and J. W. Kidson, 1984: African mean wind changes between Sahelian wet and dry periods. J. Climatol., 4 , 2733.

  • Nicholson, S. E., and I. M. Palao, 1993: A re-evaluation of rainfall variability in the Sahel. Part I. Characteristics of rainfall fluctuations. Int. J. Climatol., 13 , 371389.

    • Search Google Scholar
    • Export Citation
  • Nicholson, S. E., B. Some, and B. Kone, 2000: An analysis of recent rainfall conditions in West Africa, including rainy seasons of the 1997 El Niño and the 1998 La Niña years. J. Climate, 13 , 26282640.

    • Search Google Scholar
    • Export Citation
  • Ofori-Sarpong, E., and J. Annor, 2001: Rainfall over Accra (1901–1990). Weather, 56 , 5562.

  • Peterson, T. C., and R. S. Vose, 1997: An overview of the Global Historical Climatology Network temperature database. Bull. Amer. Meteor. Soc., 78 , 28372849.

    • Search Google Scholar
    • Export Citation
  • Rayner, N. A., D. E. Parker, E. B. Horton, C. K. Folland, L. V. Alexander, D. P. Rowell, E. C. Kent, and A. Kaplan, 2003: Global analyses of sea surface temperature, sea ice, and night marine air temperature since the late nineteenth century. J. Geophys. Res., 108 , 4407. doi:10.1029/2002JD002670.

    • Search Google Scholar
    • Export Citation
  • Ross, R. S., and T. N. Krishnamurti, 2007: Low-level African easterly wave activity and its relation to Atlantic tropical cyclogenesis in 2001. Mon. Wea. Rev., 135 , 39503964.

    • Search Google Scholar
    • Export Citation
  • Stickler, A., and Coauthors, 2010: The Comprehensive Historical Upper Air Network (CHUAN). Bull. Amer. Meteor. Soc., 91 , 741751.

  • Thorncroft, C., and K. Hodges, 2001: African easterly wave variability and its relationship to Atlantic tropical cyclone activity. J. Climate, 14 , 11661179.

    • Search Google Scholar
    • Export Citation
  • Uppala, S. M., and Coauthors, 2005: The ERA-40 Re-Analysis. Quart. J. Roy. Meteor. Soc., 131 , 29613012.

  • Vose, R. S., R. L. Schmoyer, P. M. Steurer, T. C. Peterson, R. Heim, T. R. Karl, and J. Eischeid, 1992: The Global Historical Climatology Network: Long-term monthly temperature, precipitation, sea level pressure, and station pressure data. ORNL/CDIAC-53, NDP-041, 325 pp. [Available from Carbon Dioxide Information Analysis Center, Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831].

    • Search Google Scholar
    • Export Citation
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