HR: 17:00h
AN: U24A-03 [Abstracts]
TI: Water Vapor Fluxes over the Intra-Americas Sea: Seasonal and Interannual Variability and Associations with Rainfall
AU: * Mestas-Nunez, A M
EM: alberto.mestas@tamucc.edu
AF: Texas A&M University - Corpus Christi, 6300 Ocean Drive, Corpus Christi, TX 78412, United
States
AU: Enfield, D B
EM: david.enfield@noaa.gov
AF: NOAA/Atlantic Oceanographic and Meteorological Laboratory, 4301 Rickenbacker
Causeway, Miami, FL 33149, United States
AU: Zhang, C
EM: czhang@rsmas.miami.edu
AF: RSMAS, University of Miami, 4600 Rickenbacker Causeway, Miami, FL 33149, United
States
AB:
The seasonal and interannual variability of moisture transports over the Intra-Americas Sea (including the Gulf of
Mexico and the Caribbean Sea) is evaluated using the NCEP-NCAR global reanalysis. The seasonal variability of
these moisture transports is consistent with previous studies and shows distinctive winter and summer
regimes. Boreal winter moisture is mainly delivered to the central US from the Pacific with some contribution
from the Gulf of Mexico. It is during the boreal summer that the moisture flow over the Intra-Americas Sea is most
effective in supplying the water vapor to the central US via the northern branch of the Caribbean low-level jet. The
increase of intensity of this jet during July is associated with an increase in evaporation over the Intra-Americas
Sea, consistent with mid-summer drought conditions over this region.
During both summer and winter, the interannual variability of the inflow of moisture from the Intra-Americas Sea
into central US is associated with Caribbean low-level jet variability. The source of the varying moisture is mainly
the Gulf of Mexico and the North Atlantic area just east of the Bahamas Islands and the sink is precipitation over
east-central US. The main teleconnection pattern for these interannual variations appears to be the Pacific North
American, although in boreal winter ENSO and possibly the North Atlantic Oscillation may also play a role. During
boreal summer, associations with ENSO mainly involve the zonal moisture exchange between the Intra-
Americas Sea/tropical Atlantic and the tropical Pacific.
DE: 1616 Climate variability (1635, 3305, 3309, 4215, 4513)
DE: 1620 Climate dynamics (0429, 3309)
DE: 1631 Land/atmosphere interactions (1218, 1843, 3322)
DE: 1854 Precipitation (3354)
DE: 3339 Ocean/atmosphere interactions (0312, 4504)
SC: Union [U]
MN: 2007 Joint Assembly