HR: 0800h
AN: GC51D-1074    [Abstracts]
TI: Contribution of thermal expansion to present-day sea level rise revisited
AU: * LOMBARD, A
EM: alic.lombard@notos.cst.cnes.fr
AF: LEGOS, 14 Avenue Edouard Belin, Toulouse, 31400 France
AU: CAZENAVE, A
EM: anny.cazenave@cnes.fr
AF: LEGOS, 14 Avenue Edouard Belin, Toulouse, 31400 France
AU: CABANES, C
EM: cecile.cabanes@ifremer.fr
AF: IFREMER, Centre de Brest, Plouzane, 29280 France
AU: NEREM, R
EM: nerem@colorado.edu
AF: CCAR, University of Colorado, Boulder, CO 80309 United States
AB: In this study, we revisit the contribution of thermal expansion to sea level rise of the last fifty years, comparing two global ocean temperature data sets from Levitus et al. (2000) and Ishii et al. (2003). We apply the method developed by Cabanes et al. (2001) which consists of comparing sea level records of historical tide gauges with thermosteric sea level time series interpolated from the gridded ocean temperature data. First we note that thermosteric sea level trends from Levitus and Ishii data over 1955-1994 agree well at all tide gauges sites considered here except along the coast of northeast US, north of 37øN, where the Levitus thermosteric rates appear overestimated. A similar observation was noticed by Miller and Douglas (2004) based on raw hydrographic data who found the Levitus temperatures abnormally high in the Gulf Stream region. Excluding tide gauges sites from this region (leaving 17 useful sites), we obtain, for the period 1955-1994, mean thermosteric trends of 0.4 +/- 0.3 mm/yr (Levitus data down to 500m and 3000m ) and 0.2 +/- 0.2 mm/yr (Ishii data down to 500m). Such values are more than 3 times lower than the rate of sea level rise computed with tide gauges records, of 1.7 +/- 0.7 mm/yr. This result based on gridded data sets agrees well with that of Miller and Douglas (2004) based on raw hydrographic data. The residual (observed minus thermosteric) rate of sea level rise for 1955-1994 has an average value of 1.4 +/- 0.6 mm/yr. This result confirms recent investigations suggesting a dominant eustatic contribution to last decades mean sea level rise (Antonov et al., 2001, Munk, 2003, Wadhams et al., 2004, Miller and Douglas, 2004).
DE: 4203 Analytical modeling
DE: 1655 Water cycles (1836)
DE: 1699 General or miscellaneous
DE: 1600 GLOBAL CHANGE (New category)
DE: 1635 Oceans (4203)
SC: Global Climate Change [GC]
MN: 2004 AGU Fall Meeting