In the profile cascade plots, potential temperature range 17-19 degC is indicated in red as a rough indication of the presence of EDW.

Float histories: Float 2720: as of October 7, 2006, stopped reporting (66 total profiles). Float 2721: as of September 3, 2007, stopped providing data (131 good profiles). Float 2722: as of April 27, 2006, stopped providing accurate profile data (35 good profiles). Float 2723: as of May 22, 2007, stopped providing data (110 good profiles). Float 2725: as of July 21, 2006, stopped providing accurate profile data (49 good profiles). Float 2726: as of January 18, 2007, stopped reporting (87 good profiles). Float 2713: as of October 31, 2007, stopped reporting (144 good profiles). Float 2719: as of October 13, 2007, stopped reporting (140 good profiles). Float 2724: as of April 8, 2008, stopped reporting (174 good profiles). Float 5051: as of June 28, 2010, stopped reporting: consumed its energy (164 good profiles). Float 5069: as of March 24, 2010, stopped reporting: consumed its energy (116 good profiles). Float 5068: as of November 23, 2011, stopped reporting: consumed its energy (182 good profiles). Additional plots (mixed layer and EDW properties)     Float Positions Potential Temperature Profiles Potential Temperature Contours Salinity Profiles Salinity Contours Summary 2713 SIO 2713 UW End 10/31/07 2719 SIO 2719 UW End 10/13/07 2720 SIO 2720 UW End 10/07/06 2721 SIO 2721 UW End 09/03/07 2722 SIO 2722 UW End 04/27/06 2723 SIO 2723 UW End 05/22/07 2724 SIO 2724 UW End 04/08/08 2725 SIO 2725 UW End 07/21/06 2726 SIO 2726 UW End 01/18/07 5051 SIO 5051 UW End 06/28/11 5068 SIO 5068 UW End 11/23/11 5069 SIO 5069 UW End 03/24/10

Gyre-scale context for the intensive EDW formation experiment, which is concentrated near the Gulf Stream Extension, is provided by Argo and Argo-equivalent profiling floats and very limited CTD sampling. Estimates of EDW volume are to be mapped coarsely throughout the western part of the gyre. Variations in upper ocean circulation, thermocline and oxygen structure will be mapped monthly. Our profiling floats include oxygen, unlike the WOCE floats and the acoustically-tracked floats, giving additional information on formation processes, rates and advection (Jenkins, 1982). Winter near-surface oxygen undersaturation is an indicator of convective mixing (Talley et al 2003a).

The CLIMODE Apex float program includes 9 APEX-SBE profilers with Aanderaa oxygen sensors. The floats are parked at 500 dbar and profiling from 1800 dbar to the surface, every 5 days. These and the Argo floats will yield 80 to 90 profiles per month, and will extend the WOCE EDW PALACE float study of 1997-2002 (Kwon and Riser, 2004a,b) (http://flux.ocean.washington.edu), which had 53 functioning floats, with about 40 to 170 profiles per month.

Monthly mixed layer depth, EDW volume, temperature, salinity, oxygen, and thermocline structure will be produced from the weekly float profiles. The cruises will provide some transect information. CTD profiles from ongoing programs (e.g. Bermuda time series, CLIVAR repeat hydrography) will also be incorporated. These products will provide the overall thermocline shape and circulation in which the EDW is embedded. We will also work with historical float and hydrographic data (e.g. Talley and Raymer, 1982; Talley, 1996; Joyce and Robbins, 1996; Lozier et al., 1995; Owens 1991; Molinari et al 1997; Kwon and Riser, 2004a,b), to provide the climate context for the intensive field phase (North Atlantic Oscillation phase, mixed layer properties and vigor of EDW formation, strength of recirculation and dispersal of EDW).

Hydrographic profile comparisons