The saclantcen temperature profiling buoy system

A self-recording thermistor buoy system was developed at the SACLANT ASW Research Centre to registe the variability of temperature in the upper ocean. The system consists of 20 thermistors spaced on a vertical cable between the sea surface and 250 m. The thermistors are incorporated into parallel RC circuits which, when electronically triggered, produce a pulse train wherein the individual pulse arrival times are an analog of the temperature at each sensor. The sequence, repeated every 3 min., is FM recorded within the buoy. A field experiment utilizing three buoys placed in a triangular array 8.5 km on a side, was performed in the Western Mediterranean. The buoys, taut moored in 2600 m depths and supporting recording current meters were equipped with acoustic/ time releaser systems; they recorded data for periods from 4 to 9 days. Field methods, buoy performance and data, processing techniques are discussed.