HR: 1340h
AN: A33E-1643    [Abstracts]
TI: Hurricane Alley SST Variability in 2005 and 2006
AU: * Chiodi, A M
EM: chiodi@ocean.washington.edu
AF: Joint Institute for the Study of the Atmosphere and the Ocean, Box 354235 University of Washington, Seattle, WA 98195-4235, United States
AU: * Chiodi, A M
EM: chiodi@ocean.washington.edu
AF: Pacific Marine Environmental Laboratory, NOAA/R/PMEL 7600 Sand Point Way, Seattle, WA 98115, United States
AU: Harrison, D E
EM: D.E.Harrison@noaa.gov
AF: Joint Institute for the Study of the Atmosphere and the Ocean, Box 354235 University of Washington, Seattle, WA 98195-4235, United States
AU: Harrison, D E
EM: D.E.Harrison@noaa.gov
AF: Pacific Marine Environmental Laboratory, NOAA/R/PMEL 7600 Sand Point Way, Seattle, WA 98115, United States
AB: The North Atlantic hurricane seasons of 2005 and 2006 were dramatically different for the Gulf Coast and eastern seaboard of the United States. The 2005 hurricane season was one of the most destructive seasons in history, while there was limited impact in 2006. Hurricane activity had been forecast to be above normal in 2006 but was not. One of the conspicuous differences in environmental conditions between these two years was sea surface temperature anomalies (SSTA) over a region of the Western Atlantic and Caribbean (70W-40W, 15N-30N) important for hurricane formation and intensification. SSTA was more than 1.5 standard deviations warm during the 2005 hurricane season, but was much less in 2006 through most of its hurricane season. Recent studies have highlighted the potentially important role of atmospheric dust-shielding of solar radiation in causing this SSTA difference. The intent of this study is to determine the mechanisms responsible for this SSTA difference. It is shown that the difference can be reproduced using a simple 1-dimensional ocean mixed layer model forced with surface fluxes from the NCEP/NCAR Reanalysis Project. It is found that there are two causes of SSTA difference over this region during July through September; one is latent heat flux variability caused by wind speed effects, and the second is non-linear ocean warming caused by synoptic scale atmospheric variability. Solar forcing is found to damp rather than force the year-to-year model SSTA difference, contrary to previous hypotheses based on aerosol concentration.
DE: 3307 Boundary layer processes
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
DE: 4572 Upper ocean and mixed layer processes
SC: Atmospheric Sciences [A]
MN: 2007 Fall Meeting