Ocean Science www.ocean-sci.net 1812-0784 1812-0792 3 3 2007 10.5194/os-3-363-2007 http://www.ocean-sci.net/3/363/2007/ http://www.ocean-sci.net/3/363/2007/os-3-363-2007.html http://www.ocean-sci.net/3/363/2007/os-3-363-2007.pdf 363 377 2007-08-03 Variability of Antarctic intermediate Water properties in the South Pacific Ocean M. Tomczak matthias.tomczak@flinders.edu.au School of Chemistry, Physics and Earth Sciences, Flinders University, GPO Box 2100, Adelaide SA 5001, Australia Argo float time series data are used to study the salinity field at the depth of the salinity minimum produced by Antarctic Intermediate Water (AAIW). It is found that far from showing the smooth erosion of the minimum that would result from diffusive flow, the salinity field is characterized by features of geostrophic turbulence such as fronts, eddies and intrusions. Comparison of the Argo float observations with the climatology of the World Ocean Atlas (WOA) reveals significant differences between the two data sets. Some of the differences may have their origin in problems with the WOA data density in remote regions of the South Pacific, but most are more likely produced by interannual variations of the AAIW salinity field. Armi, L. and Zenk, W.: Large lenses of highly saline Mediterranean water. J. Phys. Oceanogr., 14, 1560–1576, 1984. Conkright, M. E., Locarnini, R. A., Garcia, H. E., O'Brien, T. D., Boyer, T. P., Stephens, C., and Antonov, J. I.: World Ocean Atlas 2001: Objective Analyses, Data Statistics, and Figures, CD-ROM Documentation, National Oceanographic Data Center, Silver Spring, MD, 17 pp., 2001. Conkright, M. E., Antonov, J. I., Baranova, O., Boyer, T. P., Garcia, H. E., Gelfeld, R., Johnson, D., Locarnini, R. A., Murphy, P. P., O'Brien, T. D., Smolyar, I., and Stephens, C.: World Ocean Database 2001, Volume 1: Introduction, edited by: Levitus, S., NOAA AtlasNESDIS 42, U.S. Government Printing Office, Washington, D.C., 167 pp., 2002. Elliott, B. A. and Sanford, T. B.: The subthermocline lens D1. Part I: Description of water properties and velocity profiles, J. Phys. Oceanogr., 16, 532–548, 1986a. Ichikawa, Y., Takatsuki, Y., Mizuno, K., Shikama, N., and Takeuchi, K.: Estimation of drifting velocity and error at parking depth for Argo float, JAMSTECR, 44, 81–89 (in Japanese), 2001. McWilliams, J. C.: Submesoscale, coherent vortices in the ocean, Rev. Geophys., 23, 165–182, 1985. Oka, E.: Long-term sensor drift found in recovered Argo profiling floats, J. Oceanogr., 61, 775–781, 2005. Prater, M. D. and Sanford, T. B.: A meddy off Cape St. Vincent. Part I: Description, J. Phys. Oceanogr., 24, 1572–1586, 1994. Roemmich, D., Riser, S., Davis, R., and Desaubies, Y.: Autonomous profiling floats: Workhorse for broadscale ocean observations, Mar. Techn. Soc. J., 38(1), 31–39, 2004. Stanton, B. R.: Antarctic Intermediate Water variability in the northern New Zealand region, New Zealand J. Mar. Freshwater Res., 36, 645–654, 2002. Tomczak, M. and Andrew, C.: Eddy formation in the Antarctic Intermediate Water of the subtropical South Pacific Ocean, J. Mar. Atmos. Res., 1, 8–12, 1997. Tomczak, M. and Godfrey, J. S.: Regional Oceanography: an Introduction 2nd edn., Daya Publishing, Delhi, xi~+~390~pp., 2003. Wong, A. P. S., Bindoff, N. L., and Church, J. A.: Large-scale freshening of the intermediate waters in the Pacific and Indian Oceans, Nature, 400, 440–443, 1999. Wüst, G.: Schichtung und Zirkulation des Atlantischen Ozeans. Das Bodenwasser und die Stratosphäre, Wiss. Ergebn. Dt. Atl. Exp. "METEOR" 1925–1927, Berlin, 6, 1–288 (translated as "The stratosphere of the Atlantic Ocean" by Emery, W. J. (1978)), Amerind, 1936.