EXO Sonde performance at Buccoo Reef, 2013-present

This post is part of a planned series of posts to share the results of my recent evaluation of data produced by all of the CREWS/CCCCC buoys over their lifetimes, from 2013 to the present.  This post will discuss the performance of the EXO Sondes, which were deployed to collect sea temperature and salinity data but are also capable of monitoring other 'water quality' parameters such as turbidity, algae, fDOM, pH and DO.

At the Buccoo Reef buoy (BUTO1), performance by the EXO Sonde has been generally poor.  The Buccoo EXO was first deployed on November 27, 2013 and this analysis is based on data collected through June 4, 2015.  Although this period spans a total of 554 days, BUTO1 experienced one prolonged outage in the summer of 2014 and a few shorter maintenance operations that brought the buoy temporarily to land, so that the actual length of deployment over this period was only 464 days, or about 15 months' worth.

Here is a graph of sea temperature (°C, in blue) and salinity (PSU, in red) from BUTO1, plotted against decimal year:

Please click on this image to see it in larger form.

Over the course of the last year and a half, the EXO Sonde at Buccoo has had six periods of time during which the EXO could be said to have produced reasonable sea temperature and salinity data:

• Nov 27, 2014 to Jan 29, 2014 (63 days, after which SeaT and Sal both go bad)
• Mar 19, 2014 to May 15, 2014 (57 days, after which the buoy loses power)
• Nov 13, 2014 to Jan 17, 2015 (65 days, after which Sal goes bad)
• Feb 3, 2015 to Feb 12, 2015 (9 days, after which Sal goes bad)
• Mar 17, 2015 to May 2, 2015 (46 days, after which Sal goes bad)
• May 12, 2015 to June 4, 2015 (23 days and counting)

Based on these statistics the EXO's conductivity probe, which reports both sea temperatures and conductivities (from which salinities are calculated), has performed reasonably well for 263 days out of the buoy's 464 operational days, or about 57% of the time.

A similar analysis performed on this buoy's sister station at Speyside / Angel's Reef, Tobago (ARTO1) found that that EXO performed reasonably well for 190 days out of the buoy's 552 operational days, or about 34% of the time.  The complete analysis for that EXO may be found at this link.

(signed)
Mike Jankulak