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Webinar: Upper ocean horizontal velocity and vertical shear in the tropical North Atlantic.
Tuesday, 04 September 2018, 2:00
Tuesday, September 4, 2018. 2:00PM. Webinar: Upper ocean horizontal velocity and vertical shear in the tropical North Atlantic. Renellys Perez, NOAA. Sponsored by NOAA. More information here.
The Tropical Atlantic Current Observations Study sampled upper-ocean horizontal velocity and vertical shear from a mooring at 4degN, 23degW in order to observe the temporal and vertical structure of the currents in this region. In the first year of TACOS data, mean zonal velocity and vertical shear were strongest between 32 and 37 m, with mean near-surface eastward currents that were weaker than expected. Despite the Atlantic cold tongue being anomalously warm, energetic tropical instability waves (TIWs) were observed. Meridional velocity fluctuations were generally larger than those of zonal velocity. TIW velocity fluctuations extended down to 87 m and perturbed the thermocline and the depth of maximum vertical shear squared, although they generated only modest vertical shear when compared to the shear in boreal winter and spring. The phase of these fluctuations propagates upward to the surface with vertical phase speeds between 12 and 15 m day -1 . Coherent velocity, vertical shear, and temperature variations are examined in a composite TIW. Models and ancillary data are used to put the first year of TACOS observations into the context of the long-term variability present at 4degN, 23degW. Early results from the second year of TACOS data will also be shown.