High sampling rate thermistor string observations at the slope of Great Meteor Seamount

[摘要] A high sampling rate (1 Hz) thermistor string has been built to accommodatethe scientific need to accurately monitor high-frequency and vigorousinternal wave and overturning processes in the ocean. The thermistors andtheir custom designed electronics can register temperature at an estimatedprecision of about 0.001° C with a response time faster than 0.25 sdown to depths of 6000 m. With a quick in situ calibration using SBE 911 CTDan absolute accuracy of 0.005° C is obtained. The present stringholds 128 sensors at 0.5 m intervals, which are all read-out within 0.5 s.When sampling at 1 Hz, the batteries and the memory capacity of the recorderallow for deployments of up to 2 weeks. In this paper, the instrument isdescribed in some detail. Its performance is illustrated with examples fromthe first moored observations, which show Kelvin-Helmholtz overturning andvery high-frequency (Doppler-shifted) internal waves besides occasionallylarge turbulent bores moving up the sloping side of Great Meteor Seamount,Canary Basin, North-Atlantic Ocean.

[学科分类] 海洋学与技术