Journal of Oceanography, Vol. 60 (No. 2), pp. 253-258, 2004

Stability of Temperature and Conductivity Sensors of Argo Profiling Floats

Eitarou Oka¹* and Kentaro Ando²

¹Frontier Observational Research System for Global Change, Natsushima-cho, Yokosuka, Kanagawa 237-0061, Japan
²Japan Marine Science and Technology Center, Natsushima-cho, Yokosuka, Kanagawa 237-0061, Japan

(Received 4 March 2003; in revised form 31 May 2003; accepted 31 May 2003)

Abstract: After recalibration of the temperature and conductivity sensors of three Argo profiling floats recovered after operations for four to nine months, the results indicate that the floats basically showed no significant drift, either in temperature or salinity, and adequately fulfilled the accuracy requirement of the Argo project (0.005°C for temperature and 0.01 psu for salinity). Only the third float showed a significant offset in salinity of about -0.02 psu, as expected from comparison between the float data and the shipboard conductivity-temperature-depth data. This offset was caused by the operational error of the PROVOR-type float, in which the surface water was pumped immediately after the launch, fouling the conductivity sensor cell.