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Guinasso, N. L., Texas A&M University, College Station, USA, guinasso@tamu.edu
Mullins, R. L., Texas A&M University, College Station, USA, rmullins@ocean.tamu.edu
DiMarco, S. F., Texas A&M University, College Station, USA, dimarco@tamu.edu
Li, B. ., Texas A&M University, College Station, USA, acelibo@neo.tamu.edu
Chapman, P. ., Texas A&M University, College Station, USA, piers.chapman@tamu.edu
Walpert, J. N., Texas A&MMUniversity, College Station, USA, walpert@gerg.tamu.edu

COMPARISON OF TWO OXYGEN SENSORS ON A TOWED CTD TO STUDY HYPOXIA IN THE GULF OF MEXICO

August 2-6, 2010 we deployed an Sea Sciences Acrobat tow fish configured with both a Seabird Electronics SBE 43 oxygen sensor and a JFE Alec Co. Ltd. Rinko III oxygen sensor connected to a SeaBird SBE-19 CTD. We ran 18 onshore-offshore transects using an automated program to raise and lower the tow fish. Transects lasted 2-3 hours. At survey speeds of 2-2.6 m/s we were able to lower and raise the CTD every 2-3 minutes achieving measurements of oxygen concentrations near the sea floor with very high spatial resolution over a wide area. The relationship between oxygen measured by the SBE 43 and the Rinko was examined by treating each transect as a separate experiment. The covariance between the Rinko measurements and the Seabird measurements indicated that the SeaBird measurements lagged the Rinko by 1.08 s (N=18, sd=.073 s). After offsetting the measurements we fit a linear relationship between the Rinko and SeaBird which had a slope of 1.047 (N=18, sd=.133) and an offset of -.187 ml/l (N=18, sd= 0.025). After adjusting the measurements by these parameters, the mean difference was 0.000 ml/l and the standard deviation of the residuals was 0.097 ml/l. Some high frequency details were seen in the Rinko data that was not seen in the SeaBird observations. We suspect that the offsets between the sensors are influence by gradients in the water column, rate of raising and lowering, and the speed of the vessel as well as the temporal response of the sensors.

Poster presentation

Session #:S91
Date: 02-17-2011
Time: 16:00 - 18:00

Presentation is given by student: No

PosterID: 397