HR: 0800h
AN: OS21C-1248    [Abstracts]
TI: Comparison of Mixed Layer Depths Calculated Using the Vertically Discrete TRITON Temperature and Salinity Data
AU: * ANDO, K
EM: andouk@jamstec.go.jp
AF: IORGC/JAMSTEC, 2-15 Natsushima, Yokosuka, 237-0061 Japan
AB: To investigate the time series of mixed layer and barrier layer in the western Pacific is crucial for understanding sea surface temperature change associated with the ENSO phenomena, therefore air-sea interaction system in the tropical Pacific. The TRITON (Triangle-Trans Ocean buoy Network) buoy array, which consists the ENSO monitoring system with the TAO array by NOAA/PMEL, has been deployed in the western tropical Pacific for monitoring ocean mixed layer and barrier layer. At this time, the error analysis for mixed layer and isothermal layer depths estimation from vertically discrete temperature and salinity of the TRITON buoy is necessary for further quantitative analysis. This study investigated the comparison of several calculation methods for the mixed layer and isothermal layer depths from the TRITON data, and with the well-managed CTD profiler data from the research vessels. The methods used are based on the Sprintal and Tomzac (1992)_fs method, and the difference to the sea surface temperature was set to be 0.5 degree-C for estimation of isothermal layer depth. In this investigation, the vertical interpolations were tested for two cases, the linear interpolation and the spline (Akima method) interpolation. The new method (_gup-down_h method) by assuming the vertical movement of keeping _gfixed temperature (density) curves below isothermal (mixed) layer_h by internal tidal wave was also tested. The results of comparison indicated, in the statistic comparisons with the CTD profiler data, the estimated isothermal layer (mixed layer) depth from the spline (Akima) interpolation is the best with the errors of 10 meters (9 meters), and the estimated isothermal layer (mixed layer) depth by the new _gup-down_h method is the second with the errors of 12 meters (13 meters). For all estimations of the mixed layer depth and isothermal layer depth, the tendencies to be estimated near the depths of 50 and/or 75 meters were associated with the vertical resolution (25 meters) of the vertical positions of TRITON buoy sensors. The presentation will also include the examples of analysis in the western tropical Pacific by using these mixed layer parameters, focusing on the oceanic responses to atmospheric forcing in each phase of the 2002-2003 ENSO event.
DE: 4504 Air/sea interactions (0312)
DE: 4522 El Ni¤o
DE: 4568 Turbulence, diffusion, and mixing processes
DE: 4572 Upper ocean processes
SC: Ocean Sciences [OS]
MN: 2004 AGU Fall Meeting