Abstract:
The Northwest Tropical Atlantic Station (NTAS) was established to address the
need for accurate air-sea flux estimates and upper ocean measurements in a region with
strong sea surface temperature anomalies and the likelihood of significant local air–sea
interaction on interannual to decadal timescales. The approach is to maintain a surface
mooring outfitted for meteorological and oceanographic measurements at a site near
15°N, 51°W by successive mooring turnarounds. These observations will be used to
investigate air–sea interaction processes related to climate variability.
Deployment of the first NTAS mooring (NTAS-1) at 14°50′ N, 51°00′ W on 30
March 2001 was documented in a previous report (Plueddemann et al., 2001). This report
documents recovery of the NTAS-1 mooring and deployment of the NTAS-2 mooring at
the same site. Both moorings used 3-meter discus buoys as the surface element. These
buoys were outfitted with two Air–Sea Interaction Meteorology (ASIMET) systems.
Each system measures, records, and transmits via Argos satellite the surface
meteorological variables necessary to compute air–sea fluxes of heat, moisture and
momentum. The upper 120 m of the NTAS-1 mooring line, and the upper 150 m of the
NTAS-2 mooring line, were outfitted with oceanographic sensors for the measurement of
temperature and velocity.
The mooring turnaround was done on the NOAA Ship Ronald H. Brown, Cruise
RB-02-02, by the Upper Ocean Processes Group of the Woods Hole Oceanographic
Institution. The cruise took place between 2 and 8 March 2002. A SeaBeam bathymetry
survey of the site was done first, followed by deployment of the NTAS-2 mooring on 4
March at approximately 14°44.3′ N, 50°56.8′ W in 5043 m of water. A 24-hour
intercomparison period followed, after which the NTAS-1 mooring was recovered. This
report describes these operations, as well as some of the pre-cruise buoy preparations.
