(Woods Hole Oceanographic Institution, 1982-11)
Joyce, Terrence M.; Rintoul, Stephen R.; Barbour, R. Lorraine
The underway current profiling system used in this study consists of
a microprocessor-controlled data logger that collects and formats data
from a four-beam Ametek-Straza 300 kHz acoustic Doppler current profiler,
heading from the ship's gyrocompass, and navigation information from a
Loran-C receiver and a satellite navigation unit. Data are recorded on
magnetic tape and some real time calculations are made. The system was
first used on a May, 1981 cruise aboard the R.V. OCEANUS in the western
North Atlantic. Horizontal currents were profiled to depths of 100m.
Time averaging is required to remove effects of ship motion. Errors in
our ability to profile ocean currents are estimated to be 5-10 em s-1 for
a ten-minute vector average. An intercomparison is made with a moored
vector measuring current meter (VMCM). The mean difference in hourly-averaged
APOC and VMCM currents over the four-hour intercomparison is a
few mm s-1. Data from a variety of oceanic regimes are presented and
discussed: these regimes include two Gulf Stream crossings, a warm core
ring survey, and shallow water in a frontal zone to the east of Nantucket
Shoals.
(Woods Hole Oceanographic Institution, 1982-12)
Trask, Richard P.; Briscoe, Melbourne G.; Pennington, Nancy J.
Plans for the Long Term Upper Ocean Study evolved over several years.
As the plans became more definite a two year period was devoted to
engineering tests at the LOTUS site (34°N, 70°W). Many aspects of the
proposed plans were implemented during this period in order to evaluate
the performance of the equipment and instrumentation. This report presents
a summary of the planning and testing periods up to but not including the
first science deployments in May 1982. Historical data collected at the
LOTUS site prior to the engineering tests and the data collected as part
of the engineering tests are presented.
