TCs rainfall and TCs rainfall efficiency simulated in a high resolution climate model

According to the 4th Intergovernmental Panel on Climate Change (IPCC, 2007), it is difficult to distinguish any man-induced long-term trend of the cyclonic activity and scenarios for a warmed climate do not converge on any trend in the intensity and the number of Tropical Cyclones (TCs). Most recent studies assessing the associated precipitation to TCs indicate an increase in the North Atlantic basin which may be induced by a warmer climate (Lau et al., 2008).

Precipitation associated to TCs may be quite destructive in some regions. For example in the USA, they are at the origin of 600 deaths between 1970 and 1999 meaning 57% of the deaths due to hurricane (Rappaport, 2000). Thus associated rainfall is a relevant topic for climate change studies. We adressed this question in this study, analysing the TCs rainfall from the high resolution climate model from CNRM, ARPEGE.

We also defined what could be called the "TC precipitation efficiency" (TCPE) as the mean precipitation per TC day over each grid point. We investigated the ability of the model to represent this variable using both tracking and composite methodologies developped in Chauvin et al.(2006).

References

K.-M. Lau, Y.P. Zhou and H.-T Wu, 2008: Have tropical cyclones been feeding more extreme rainfall ? J. Geophys. Res., 113, D23113, doi: 10.1029/2008JD009963. Chauvin F., J.F. Royer and M. Deque, 2006: Response of hurricane type vortices to global warming as simulated by ARPEGE-Climat at high resolution. Clim. Dyn., 27(4), 377-399. IPCC, 2007: The physical science basis, in: S. Solomon et al., Cambridge University Press. Rappaport E.N., 2000: Loss of life in the United States associated with recent Atlantic tropical cyclones. Bull. Amer. Meteor. Soc., 81, 2065-2073.