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

• Published in: Ocean Science
• Main Authors: Haren, H., Groenewegen, R., Laan, M., Koster, B.
• Format: Text
• Language: English
• Published: 2018
• Subjects: Meteor Seamount; North Atlantic
• Online Access: https://doi.org/10.5194/os-1-17-2005; https://os.copernicus.org/articles/1/17/2005/

A high sampling rate (1 Hz) thermistor string has been built to accommodate the scientific need to accurately monitor high-frequency and vigorous internal wave and overturning processes in the ocean. The thermistors and their custom designed electronics can register temperature at an estimated precision of about 0.001° C with a response time faster than 0.25 s down to depths of 6000 m. With a quick in situ calibration using SBE 911 CTD an absolute accuracy of 0.005° C is obtained. The present string holds 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 recorder allow for deployments of up to 2 weeks. In this paper, the instrument is described in some detail. Its performance is illustrated with examples from the first moored observations, which show Kelvin-Helmholtz overturning and very high-frequency (Doppler-shifted) internal waves besides occasionally large turbulent bores moving up the sloping side of Great Meteor Seamount, Canary Basin, North-Atlantic Ocean.