S-PALACE Instrument Description

ALACE floats  were originally developed by Russ Davis' group at Scripps and have been in use since the mid 1980s. Most of the ALACE floats deployed were only capable of returning temperature profiles. The addition of a conductivity cell to allow salinity profiles to also be returned is an enhancement developed at Scripps by Jeff Sherman.  The floats currently in use at  WHOI are close cousins of those, using a conductivity cell from Falmouth Scientific, Inc.  The S-PALACE floats we use are assembled, ballasted, programmed, and tested by the WHOI float group using components from Webb Research, Scripps and Falmouth Scientific. More information on the S-PALACE is provided on the Webb Research pages and in a description on the AOML pages. 

Our first test S-PALACE float was deployed in the Labrador Sea in 1995.  Four other test floats were deployed there and one was deployed in the Sargasso Sea in 1996. We are currently acquiring profiles from 40 floats deployed as part of ACCE.  Though early returns were mixed, this latest batch of floats have performed reasonably well.  Biological fouling seems to have affected the conductivity sensor on some floats, but others are profiling and transmitting perfectly.

The schematic at the right shows the parts of a S-PALACE float.  Both external and internal parts are labeled.  Photographs of the components inside of a float can be viewed by clicking here. The floats each weigh about 80 lbs in air. The pressure case diameter is 6 inches, and was accidentally omitted on the schematic.

A photographic sequence of deploying an S-PALACE float, taken by AOML scientists during R/V Seward Johnson cruise 97-03 in the tropical Atlantic is shown. Note how the float is lowered carefully over the stern. (Use the "back" key to return to this site- there is no return link.) 

Some partially assembled floats are shown in the photograph below. These are probably at the stage of being ballasted prior to a cruise.

 

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