High quality sea surface temperature for volunteer observing ships

The Upper Ocean Processes (UOP) group at the Woods Hole Oceanographic Institution (WHOI) has as its goal "to study and better understand the processes in the upper ocean". Instrumentation capable of obtaining high-quality data that meets the standards of the World Ocean Circulation Experiment (WOCE) is critical to achieving this goal. The UOP group has met this requirement with a proven record based on past performance with measurements made from surface buoys, research ships and Volunteer Observing Ships (VOS). The IMET (Improved METeorology) systems, developed by the UOP group have now evolved into a third generation configuration. This paper describes the strengths and weaknesses of the IMET systems based on field experience and the resulting evolution into instruments designed specifically for VOS. The VOS Sea-Surface Temperature (SST) is described in detail. Based on a study of SST from VOS in the North Atlantic by Kent and Taylor, a sensor mounted on the inside of the ships hull at the water-line provides higher quality data than sea water intakes used previously. The new SST instrument is, therefore, configured to mount inside the hull. The instrument is a stand-alone, self-powered, self-recording unit that can communicate to a remote data transmitter using the IMET protocol.