Moored Salinity Time Series Measurements at 0°, 140°W

Abstract

This study describes moored salinity time series measurements in a biologically productive equatorial upwelling regime in the Pacific Ocean (0°, 140°W). Data were collected at 26 m and at 100 m for 13 months during 1987?1988 using four SEACAT conductivity and temperature recorders equipped with optional antifouling attachments. Laboratory Pre- and post-deployment calibrations indicate that the instrumental drift in SEACAT salinity measurements was typically <0.015 psu with a maximum of 0.055 psu for sequential 6?7 month long mooring deployments. Root mean square (rms) differences with CTD casts taken within a few nautical miles of the moorings were ?0.05 psu. These values are an order of magnitude smaller than the observed range of salinity variations. Little biogenic material was found on the SEACAT sensors on recovery. Thus, we infer that the antifouling attachments used were effective and that similar favorable results using SEACATs can be expected at other times and places in equatorial upwelling regimes.