Ocean Science www.ocean-sci.net 1812-0784 1812-0792 3 4 2007 10.5194/os-3-485-2007 http://www.ocean-sci.net/3/485/2007/ http://www.ocean-sci.net/3/485/2007/os-3-485-2007.html http://www.ocean-sci.net/3/485/2007/os-3-485-2007.pdf 485 490 2007-11-28 Comparing the steric height in the Northern Atlantic with satellite altimetry V. O. Ivchenko voi@noc.soton.ac.uk S. D. Danilov D. V. Sidorenko J. Schröter M. Wenzel D. L. Aleynik Alfred Wegener Institute for Polar and Marine Research, Bremerhaven, Germany The University of Plymouth, Plymouth, UK Anomalies of dynamic height derived from an analysis of Argo profiling buoys data are analysed to assess the relative roles of contributions from temperature and salinity over the North Atlantic for the period of 1999–2004. They are compared with dynamic topography anomalies based on TOPEX/Poseidon and Jason altimetry. It is shown that the halosteric contribution to the anomalies of dynamic height is comparable in magnitude to the thermosteric one over the period analyzed. Taking both salinity and temperature into account improves the agreement between zonally averaged trends in the satellite dynamic topography and dynamic height increasing the correlation between them to 0.73 from 0.63 when only temperature variability is taken into account. The implication of this result is that the salinity contribution cannot be neglected in the North Atlantic and that one cannot rely on estimating the thermosteric part by anomalies in the sea surface dynamic topography derived from the satellite altimetry. Antonov, J. I., Levitus, S., and Boyer, T. P.: Steric sea level variations during 1957–1994: Importance of salinity. J. Geophys. Res., 107(C12), 8013, doi:10.1029/2001JC000964, 2002. Bretherton, F. P., Davis, R. E., and Fandry, C. B.: A technique for objective analysis and design of oceanographic experiments applied to MODE-73, Deep-Sea Res., 23, 559–582, 1976. Gandin, L. S.: Objective analysis of meteorological fields. \em Leningrad, Gidrometeoizdat, 287 pp. (in Russian), English translation No. 1373 by Israel Program for Scientific Translations, (1965), 242 pp., 1963 Gill, A.E.: Atmosphere-Ocean Dynamics. Academic Press, 662 pp., 1982. Gilson, J., Roemmich, D., Cornuelle, B., and Fu, L.-L.: Relashionship of TOPEX/Poseidon altimetric height to steric height and circulation in the North Pacific, J. Geophys. Res., 103, 12, 27 947–27 965, 1998. Ivchenko V. O., Wells, N. C., and Aleynik, D. L.: Anomaly of heat content in the Northern Atlantic in the last 7 years: is the ocean warming or cooling?, Geophys. Res. Lett., 33, L22606, doi:10.1029/2006GL027691, 2006. Lavender, K. L., Owens, W. B., and Davis, R. E.: The mid-depth circulation of the subpolar North Atlantic Ocean as measured by subsurface floats, Deep-Sea Res. , 52, 767–785, 2005. Maes, C.: Estimating the influence of salinity on sea level anomaly in the ocean, Geophys. Res. Lett., 25(19), 3551–3554, 1998. Stammer, D.: Steric and wind-induced changes in TOPEX/POSEIDON large-scale sea surface topography observations, J. Geophys. Res., 102, 9, 20 987–21 009, 1997. Stephens, C., Antonov, J. I., Boyer, T. P., Conkright, M. E., Locarnini, R., and O$'$Brien, T. D.: World Ocean Atlas 2001, 1: Temperature (CD-ROM), eds. by S. Levitus, NOAA Atlas NESDIS 49, U.S. Govt. Printing Office, Washington, D. C., 2002. White, W. and Tai, C.-K.: Inferring interannual changes in global upper ocean heat storage from TOPEX altimetry, J. Geophys. Res., 100, 24 943–24 954, 1995. Willis J. K., Roemmich, D., and Cornuelle, B.: Combining altimetric height with broadscale profile data to estimate steric height, heat storage, subsurface temperature, and sea-surface temperature variability. J. Geophys. Res., 108, C93292, doi:10.1029/2002JC001755, 2003. Willis J. K., Roemmich, D., and Cornuelle, B.: Interannual variability in upper ocean heat content, temperature, and thermosteric expansion on global scales, J. Geophys. Res., 109, C12036, doi:10.1029/2003JC002260, 2004. Yan, X.-H., Niiler, P. P., Nadiga, S. K., Stewart, R. H., and Cayan, D. R.: Seasonal heat storage in the North Pacific: 1976–1989, J. Geophys. Res., 100, 6899–6926, 1995.