HR: 17:05h
AN: OS12C-05    [PDF]
TI: Diagnostic Studies of Global Oceanic Evaporation Variations
AU: * Xing, Y
EM: yxing@gmu.edu
AF: SCS/CEOSR, MSN 5C3, George Mason University, 4400 University Dr., Fairfax, VA 22030 United States
AU: Chiu, L S
AF: NASA/GSFC, NASA/GSFC, Greenbelt, MD 20771 United States
AU: Chang, A T
AF: NASA/GSFC, NASA/GSFC, Greenbelt, MD 20771 United States
AB: Analyses of global oceanic evaporation derived from the version 2 of the Goddard Sea Surface turbulent Flux data set (GSSTF2) show significant long-term trends and large inter-annual variations. Parameters that affect the oceanic evaporation such as surface wind speed, sea-air humidity difference, presented in the same data set were examined. The purpose is to determine the cause of the increasing trend in the GSSTF2 latent flux data over the period of 1988-2000. An increase of domain average wind speed (6%) was found over the same period, along with an increase of sea-air humidity difference (11%). These results are consistent with the trends in latent heat flux, which is approximately proportional to the product of the two. Sea-air humidity difference is computed as sea surface humidity minus sea surface air humidity, therefore these two parameters were examined as well. A 1% increase and a 2.4% decrease were found in sea surface humidity and sea surface air humidity respectively, which explains the increase of sea-air humidity difference. The boundary layer (lowest 500 meters) precipitable water was also examined and a 3% decrease was found. Because it is the basis for deriving sea surface air humidity its decrease is consistent with the decrease of the sea surface air humidity. An EOF analysis will be performed for each parameter to evaluate the contribution to variances associated with the trends and interannual variations. An Empirical Mode Decomposition will be applied to the principal EOF time series to examining the intrinsic modes of the time series. Combined EOF analysis will also be applied to selected parameters to examine the coupling between the different parameters.
DE: 0933 Remote sensing
DE: 1655 Water cycles (1836)
DE: 1800 HYDROLOGY
DE: 1833 Hydroclimatology
DE: 1836 Hydrologic budget (1655)
SC: Ocean Sciences [OS]
MN: 2003 Fall Meeting