One of our drifters (DISL023) released at the 20-meter isobath on April 26, 2012 woke up after an extended nap and started reporting again on October 16, 2012. In the days that followed, the drifter made it into the Loop Current, scooting quickly across the southern portion of the Gulf of Mexico headed toward Fort Jefferson in the Dry Tortugas at speeds approaching 2 knots. The drifter has now merged with the Florida Current. Click on the image at right for the interactive tracking page. Also, you’ll see a small embedded tracker as the second item in the left hand column of this page.
The figure below shows a comparison of the drifter trajectory and mean ocean surface currents for the period 10/15 – 10/25. The data were obtained from the NOAA OSCAR system, which provides satellite derived estimates of ocean surface currents*. The inset panel shows more detail around the drifter trajectory, along with drifter speeds (m/s) and position dates (10/16, 10/26). Note the excellent agreement between drifter speed and ocean current magnitude (using the color scale at right). Clicking on the image below will take you to an enlarged version for easier viewing.
OSCAR mean surface currents for the period Oct 15 – 25, 2012 overlaid with the trajectory of DISL023.
*Bonjean F. and G.S.E. Lagerloef, 2002: Diagnostic Model and Analysis of the Surface Currents in the Tropical Pacific Ocean, Journal of Physical Oceanography, Vol. 32, No. 10, pages 2938-2954.
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