CMICE 76: A current meter intercomparison experiment conducted off Long Island in February-March 1976

Abstract

A current meter intercomparison experiment (called CMICE 76) was conducted about 6 km off the southern coast of Long Island near <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">40\deg</tex> 47'N, <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">72\deg</tex> 30'W during February and March, 1976. A total of 20 current meters were deployed on six moorings set in a roughly linear array parallel to the local coastline and topography. The instruments included the Aanderaa RCM-4, the AMF VACM, the Brookhaven National Laboratory spar buoy system using cylindrical and spherical Marsh-McBirney electromagnetic sensors, the EG&G 850 and CT-3, and the Chesapeake Bay Institute-modified ENDECO 105. Local mean water depth was 27.8 m and current meters were clustered near four depth levels (3.5 m, 7.4 m, 15.7 m, and 25.0 m). Wave data were also obtained at the array site, and 10 m wind and tidal data were obtained from nearby coastal stations. Intercomparisons of one hour vector average velocities measured with similar instruments deployed near the same depth level indicated sufficient horizontal homogeneity that most differences in the observed current data have been atrributed to real differences in instrument and mooring performance. Detailed discussions of the observed data, instrument and mooring characteristics and performance, and the effect of surface wave and wave-induced mooring motion on different measurement systems are presented.