11.1
Plenary Talk: The Argo Project: Broadscale ocean observations in the Southern Hemisphere
Dean Roemmich, SIO/Univ. Of California, La Jolla, CA; and A. S. Team
The Argo Project marks the first globally repeating measurements of subsurface temperature, salinity, and velocity, with the data available in near real-time (http://www. coriolis.eu.org). Over 500 Argo floats are presently active worldwide (http://argo. jcommops.org). The array is planned to have 3000 floats by the end of 2005 and then to be maintained at that level. There are 14 nations committed to providing Argo floats, and many others that will assist with logistics and deployment and in utilization of data.
The goal of Argo is to observe large-scale variability in the heat and hydrological cycles, including patterns in heat content, salinity anomaly, and transport by ocean circulation. Upper ocean temperature and salinity variability mirrors the effects of anomalous air-sea exchanges of heat and freshwater. Deeper in the water column, anomalous temperature and salinity are the result of subduction and advection of interannual and decadal climate signals. In addition to tracking variability, Southern Hemisphere Argo floats will explore remote regions of the globe where little is known of mean properties and ocean circulation. A number of examples of tropical and southern results from the early Argo dataset are described in this presentation, including surface layer variability, mode water formation, and thermocline and mid-depth T/S changes and circulations. Argo has many applications, including operational uses as well as research. Argo data are contributing substantially to the subsurface dataset used for data assimilation and model initialization.
The Southern Hemisphere oceans provide a strong challenge for Argo. In the completed Argo array, two-thirds of floats must be deployed south of the equator because of the hemispheric asymmetry in ocean area. Nearly all of the float-providing nations are in the north. Hence, both regional priorities and problems of access to remote ocean locations must be overcome for the program to succeed. There has never been a sustained ocean-scale array of subsurface measurements in the Southern Hemisphere, but the scientific payoff will be great. Southern Hemisphere deployments have begun and there are regional arrays of floats in each of the ocean basins. Large numbers of floats will be deployed in southern waters beginning in 2003.
Session 11, The Southern Hemisphere oceans and air-sea interactions II
Wednesday, 26 March 2003, 10:30 AM-1:30 PM
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