Jan 9, 2014

Influence of atmospheric and sea surface temperature on the size of hurricane Catarina

Raluca Radu, Ralf Toumi andJared Phau
Quarterly Journal of the Royal Meteorological Society
  • The factors that influence the size of tropical cyclones (TCs) are not completely understood.
  • Uses high-resolution numerical simulations of hurricane Catarina in the South Atlantic, which indicate that the TC size increases proportionally to the surface latent heat flux, when atmospheric and sea surface temperature (SST) are increased
  • Defines TC size as the area enclosed by three wind thresholds: gale-force winds, damaging-force winds and hurricane-force winds
  • Finds the enlargement increases sharply with the wind threshold
  • Finds that, depending on the wind threshold, the area can increase by more than an order of magnitude when air and sea temperature are both increased by 2 °C
  • Finds there is a clear linear relationship between the size increase and the latent heat flux during the TC lifetime
  • Finds the size effect is driven initially by the enhanced air–sea moisture contrast and the surface winds become predominant only in the later stages
  • Concludes that temperature changes may therefore have a profound impact on cyclone size