The Northwest Tropical Atlantic Station (NTAS): NTAS-21 Mooring Turnaround Cruise Report Cruise On Board RV Ronald H. Brown JOctober 6-25, 2022 Bridgetown, Barbados – Bridgetown, Barbados

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 are used to investigate air–sea interaction processes related to climate variability. The NTAS Ocean Reference Station (ORS NTAS) is supported by the National Oceanic and Atmospheric Administration’s (NOAA) Global Ocean Monitoring and Observing (GOMO) Program (formerly Ocean Observing and Monitoring Division). This report documents recovery of the NTAS-20, the final mooring of the NTAS time-series. The NTAS moorings use Surlyn foam buoys as the surface element. These buoys were outfitted with two Air–Sea Interaction Meteorology (ASIMET) systems. Each system measures, records, and transmits via satellite the surface meteorological variables necessary to compute air–sea fluxes of heat, moisture, and momentum. The upper 160 m of the mooring line were outfitted with oceanographic sensors for the measurement of temperature, salinity, and velocity. The mooring recovery was done by the Upper Ocean Processes Group of the Woods Hole Oceanographic Institution (WHOI) and Drew Cole, onboard R/V Ronald H. Brown, Cruise RB-22-04. The cruise took place between October 6 and 25 2022. Other operations during the cruise consisted of the intercomparison between ship and NTAS buoy measurements, turnaround of Meridional Overturning Variability Experiment (MOVE) subsurface mooring array, CTD casts, and four Argo floats deployments. MOVE is designed to monitor the integrated deep meridional flow in the tropical North Atlantic. This report describes these operations.