10B.1
An assessment of low frequency changes in tropical cyclone formation in the North Atlantic basin
Philip Pegion, NASA/GSFC/GMAO/SAIC, Greenbelt, MD; and S. D. Schubert, M. Suarez, K. Emanuel, and J. Bacmeister
The Seasonal Genesis Parameter (SGP) and the Genesis Potential Index (GPI) are two statistical tools developed to show regions that are favorable for tropical cyclone formation. The major difference in these two estimates is that SGP uses a fixed SST value of 26 C as a reference point , where as the GPI calculates stability in the column without any arbitrary reference point. These two indices are calculated on output of century long simulations of the NSIPP-1 AGCM.
The interannual variations of the two indices are similar, but the low-frequency behavior of the two indices differ. SGP shows an increase over the 20th Century, while GPI only shows fluctuations on the inter-decadal timescale. Similar analyses with several model integrations from the IPCC 4th Assessment Climate of the 20th Century simulations will attempt to separate changes associated with global warming and that of the North Atlantic Multidecadal oscillation.
Recorded presentationSession 10B, Climate of the 20th Century (C20C) Part III
Wednesday, 23 January 2008, 10:30 AM-12:00 PM, 217-218
Next paper