Ocean Science www.ocean-sci.net 1812-0784 1812-0792 1 1 2005 10.5194/os-1-17-2005 http://www.ocean-sci.net/1/17/2005/ http://www.ocean-sci.net/1/17/2005/os-1-17-2005.html http://www.ocean-sci.net/1/17/2005/os-1-17-2005.pdf 17 28 2005-05-10 High sampling rate thermistor string observations at the slope of Great Meteor Seamount H. van Haren R. Groenewegen M. Laan B. Koster Royal Netherlands Institute for Sea Research (NIOZ), P.O. Box 59, 1790 AB Den Burg, The Netherlands 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.