As part of the CLIVAR Mode Water Dynamics Experiment (CLIMODE; see http://climode.org) we are deploying acoustically-tracked, bobbing, profiling floats to study the formation and dispersal of eighteen degree water (EDW) in the subtropical Atlantic. The bobbers drift on the 18.5C temperature surface. Once every three days they bob vertically between the 17 and 20C isotherms to measure EDW thickness and stratification. Once every 15-30 days the bobbers collect a 1000m temperature profile before surfacing to transmit data via Service Argos.

The acoustic source arrray was recovered in November 2007. We are currently in the process of constructing detailed bobber trajectories. As of March 2009, most of the bobbers are still operational and continue to transmit position and stratification data regularly.

The figures below show the satellite-derived position history of the CLIMODE bobbers. The top panel shows low-resolution trajectories, and the bottom panel the individual Argos fixes. The temporal resolution in both panels is approximately one month. The final acoustically-tracked float trajectories (currently being processed) will have a temporal resolution of one day.

The symbols used in these figures are as follows: Bobber postions are indicated by numbered black crosses, launch locations by green squares, and the array of sound source moorings by red circles. The yellow stippled region indicates monthly-mean observations of the Gulf Stream north wall position since 1966 (courtesy Fisheries and Oceans Canada / MEDS)

Bobber	Position	Profiles	Contours	Temp & Press	Engineering	RAFOS TOA
37518 D: 28-Jul-2005 L: 09-Dec-2007 N: 21-Dec-2007 bobs: 284
38575 D: 04-Mar-2007 L: 22-May-2009 N: 21-Jun-2009 bobs: 260
38576 D: 14-Nov-2005 L: 01-Jul-2008 N: 31-Jul-2008 bobs: 270
38577 D: 15-Nov-2005 L: 12-Aug-2006 N: 11-Sep-2006 bobs: 90
38581 D: 16-Nov-2005 L: 30-Nov-2008 N: 30-Dec-2008 bobs: 360
38582 D: 17-Nov-2005 L: 06-Jan-2008 N: 05-Feb-2008 bobs: 250
38585 D: 18-Nov-2005 L: 31-May-2009 N: 30-Jun-2009 bobs: 430
38589 D: 21-Nov-2005 L: 04-May-2009 N: 03-Jun-2009 bobs: 420
38590 D: 22-Nov-2005 L: 11-Mar-2008 N: 10-Apr-2008 bobs: 280
38597 D: 24-Jan-2006 L: 10-Sep-2008 N: 10-Oct-2008 bobs: 290
38598 D: 22-Jan-2006 L: 06-May-2009 N: 05-Jun-2009 bobs: 400
38599 D: 24-Nov-2006 L: 12-May-2009 N: 11-Jun-2009 bobs: 300
38600 D: 24-Nov-2006 L: 12-May-2009 N: 11-Jun-2009 bobs: 300
38601 D: 25-Nov-2006 L: 13-May-2009 N: 12-Jun-2009 bobs: 290
38603 D: 29-Jan-2006 L: 13-May-2009 N: 12-Jun-2009 bobs: 400
38604 D: 19-Feb-2007 L: 10-Mar-2009 N: 09-Apr-2009 bobs: 220
38605 D: 25-Jan-2006 L: 09-May-2009 N: 08-Jun-2009 bobs: 370
38608 D: 27-Nov-2006 L: 15-May-2009 N: 14-Jun-2009 bobs: 300
39060 D: 25-Jan-2006 L: 14-May-2008 N: 13-Jun-2008 bobs: 260
39448 D: 25-Jan-2006 L: 09-May-2009 N: 08-Jun-2009 bobs: 390
39449 D: 23-Jan-2006 L: 19-May-2007 N: 18-Jun-2007 bobs: 160
39470 D: 25-Feb-2007 L: 15-May-2009 N: 14-Jun-2009 bobs: 270
39471 D: 27-Jan-2006 L: 11-May-2009 N: 10-Jun-2009 bobs: 400
39472 D: 28-Jan-2006 L: 18-Jan-2008 N: 17-Feb-2008 bobs: 240
39473 D: 26-Feb-2007 L: 16-May-2009 N: 15-Jun-2009 bobs: 270
39474 D: 28-Nov-2006 L: 16-May-2009 N: 15-Jun-2009 bobs: 300
39475 D: 22-Jan-2006 L: 06-May-2009 N: 05-Jun-2009 bobs: 400
39476 D: 20-Jan-2006 L: 28-May-2009 N: 09-Jun-2009 bobs: 408
39477 D: 03-Mar-2007 L: 22-May-2009 N: 21-Jun-2009 bobs: 270
39720 D: 13-Mar-2007 L: 31-May-2009 N: 30-Jun-2009 bobs: 270
39721 D: 24-Jan-2006 L: 13-Apr-2008 N: 13-May-2008 bobs: 260
39722 D: 27-Jan-2006 L: 11-May-2009 N: 10-Jun-2009 bobs: 390
39726 D: 19-Mar-2007 L: 07-May-2009 N: 06-Jun-2009 bobs: 260
39729 D: 04-Mar-2007 L: 22-May-2009 N: 21-Jun-2009 bobs: 270
39733 D: 13-Mar-2007 L: 01-May-2009 N: 31-May-2009 bobs: 260
39736 D: 03-Mar-2007 L: 21-May-2009 N: 20-Jun-2009 bobs: 270
39763 D: 26-Feb-2007 L: 16-May-2009 N: 15-Jun-2009 bobs: 260
39765 D: 11-Feb-2007 L: 02-Dec-2008 N: 01-Jan-2009 bobs: 220
39766 D: 04-Mar-2007 L: 22-May-2009 N: 21-Jun-2009 bobs: 270
39793 D: 10-Feb-2007 L: 30-May-2009 N: 29-Jun-2009 bobs: 270