AIRBORNE EXPENDABLE CURRENT, TEMPERATURE AND SALINITY PROFILING IN EPIC

L.  Shay1, T. Cook1, S. D. Jacob2, C. Zhang1, M. McGauley1

1Division of Meteorology and Physical Oceanography 

Rosenstiel  School  of   Marine   and  Atmospheric Science

University   of  Miami 

Miami, Florida 33149, USA

2 Goddard Earth Science and Technology Center

University of Maryland Baltimore County

NASA, Goddard Space Flight Center

Baltimore, MD 21250

During the NSF/NOAA sponsored Eastern Pacific Investigation of Climate (EPIC) 2001 field program, oceanic current, temperature and salinity profiles were measured from AXCPs, AXCTDs and AXBTs deployed from the National Center of Atmospheric Research (NCAR) WC-130J and the National Oceanographic and Atmospheric Administration (NOAA) WP-3D research aircraft. A total of nineteen research missions were conducted in the ITCZ/warm pool over a 400 km x 400 km grid centered on the NOAA R/V Brown and R/V New Horizon at 10oN, 95oW and along the 95oW TAO mooring array transect. Profilers in the ITCZ/warm pool grids were deployed at 50 km intervals with 9 stations per section on a staggered B grid with temperature profiles at each grid point. GPS sondes were deployed at AXCP drop locations from the NOAA WP-3D in the grid to reduce flight-level winds to the surface as well as examine the atmospheric structure relative to the R/V Ron Brown soundings. The 95oW equatorial transects and SST fronts were observed from the NCAR WC-130J. From both of these platforms, probe success rates were about 85%. In many cases, the AXCPs and AXCTDs provided data to 1500 and 1000 m, respectively.

For the AXCTD profiles, temperature and salinity profiles were compared to CTD profiles from the R/V Brown. While the T/S relationships revealed similar structure, the AXCTD data also suggest significant variability over the meso to large scales. Mixed layer depths ranged from 28 to 40 m and were associated with currents of 30 to 50 cm s-1 in the warm pool. Deep current structures of O(10 cm s-1) were detected by the current profilers..  Preliminary inspection of the transect data suggest a reasonable comparison to R/V Brown CTD and TAO mooring data. These aircraft-based measurements provided spatial context in examining the upper ocean response and air-sea interactions relative to the ships and moorings.