A characterization of the Equatorial Undercurrent upon its approach to the Galápagos Archipelago

The objective of this proposed project plan is to characterize the flow of the Equatorial Undercurrent (EUC) upon its approach and subsequent bifurcation around the Archipiélago de Colón (Galápagos Islands). The three methods of data acquisition that will be employed are as follows. A combination of transects to the north, west, and south of Isabela Island will gather water flow data using a 75 MHz hull-mounted Acoustic Doppler Current Profiler (ADCP) on the R/V Thomas G. Thompson. Various Conductivity, Temperature, and Depth (CTD) casts, mounted with additional sensors, will profile stations along ADCP transects and elsewhere in Isabela’s vicinity to profile the local water mass properties, namely, salinity, temperature, and dissolved oxygen. Finally, ARGOS and Iridium Drifters will be deployed in each bifurcated core of the EUC (one Drifter on the north side of Isablea, the other Drifter on the south side of Isabela) in attempt to identify the paths of the bifurcated EUC core flows. The importance of identifying the location, magnitude, and subsequent distribution of the EUC lies not only in improved parameterization, but also for the availability of data for comparison to other seasonal and interannual phenomena