The intensity of precipitation during extratropical cyclones in global warming simulations: a link to cyclone intensity?

Article English OPEN
Watterson, I. G. (2006)

Simulations of global warming over the coming century from two CSIRO GCMs are analysed to assess changes in the intensity of extratropical cyclones, and the potential role of increased latent heating associated with precipitation during cyclones. A simple surface cyclone detection scheme is applied to a four-member ensemble of simulations from the Mark 2 GCM, under rising greenhouse gas concentrations. The seasonal distribution of cyclones appears broadly realistic during 1961–1990. By 2071–2100, with 3 K global warming, numbers over 20°N to 70°N decrease by 6% in winter and 2% annually, with similar results for the south. The average intensity of cyclones, from relative central pressure and other measures, is largely unchanged however. 30-yr extremes of dynamic intensity also show little clear change, including values averaged over continents. Mean rain rates at cyclone centres are typically at least double rates from all days. Rates during cyclones increase by an average 14% in the northern winter under global warming. Rates over adjacent grid squares and during the previous day increase similarly, as do extreme rates. Results from simulations of the higher-resolution (1.8° grid) Mark 3 GCM are similar, with widespread increases in rain rates but not in cyclone intensity. The analyses suggest that latent heating during storms increases, as anticipated due to the increased moisture capacity of the warmer atmosphere. However, any role for enhanced heating in storm development in the GCMs is apparently masked by other factors. An exception is a 5% increase in extreme intensity around 55°S in Mark 3, despite decreased numbers of lows, a factor assessed using extreme value theory. Further studies with yet higher-resolution models may be needed to examine the potential realism of these results, particularly with regard to extremes at smaller scale.
  • References (23)
    23 references, page 1 of 3

    Ahmadi-givi, F., Graig, G. C. and Plant, R. S. 2004. The dynamics of a mid-latitude cyclone with very strong latent heat release. Q. J. R. Meteorol. Soc. 130, 295-323.

    Carnell, R. E. and Senior, C. A. 1998. Changes in mid-latitude variability due to increasing greenhouse gases and sulphate aerosols. Climate Dyn. 14, 369-383.

    Cubasch, U., Meehl, G. A., Boer, G. J., Stouffer, R. J., Dix, M. and co-authors. 2001. Projections of future climate change. In: Climate Change 2001: The Scientific Basis (eds. J. T. Houghton, Y. Ding, D. J. Griggs, M. Noguer, P. J. van der Linden et al.). Cambridge Univ. Press, Cambridge, 525-582.

    Gordon, H. B. and O'Farrell, S. P. 1997. Transient climate change in the CSIRO coupled model with dynamic sea ice. Mon. Wea. Rev. 125, 875-907.

    Gordon, H. B., Rotstayn, L. D., McGregor, J. L., Dix, M. R., Kowalczyk, E. A. and co-authors. 2002. The CSIRO Mk3 climate system model. Technical Paper 60, CSIRO Division of Atmospheric Research. 2002a.pdf.

    Gregory, D. and Rowntree, P. R. 1990. A mass flux convection scheme with representation of cloud ensemble characteristics and stabilitydependent closure. Mon. Wea. Rev. 118, 1483-1506.

    Gutowski, Jr, P. W., Branscome, L. E. and Stewart, D. 1992. Life cycle of moist baroclinic eddies. J. Atmos. Sci. 49, 306-319.

    Hall, N. M. J., Hoskins, B. J., Valdes, P. J. and Senior, C. A. 1994. Storm tracks in a high-resolution GCM with doubled carbon dioxide. Q. J. R. Meteorol. Soc. 120, 1209-1230.

    Hennessy, K. J., Gregory, J. M. and Mitchell, J. F. B. 1997. Changes in daily precipitation under enhanced greenhouse conditions. Climate Dyn. 13, 667-680.

    Kaas, E., Andersen, U., Flather, R. A., Williams, J. A., Blackman, D. L. and co-authors, 2001. Synthesis of the STOWASUS-2100 project: regional storm, wave and surge scenarios for the 2100 century. Rep. 01-3, Danish Climate Centre, Danish Meteorological Institute, Copenhagen (available from

  • Metrics
    No metrics available
Share - Bookmark