AirT/RH 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 analog instruments which measure air temperature (AirT) and relative humidity (RH).  These analog reading serve as a basis of comparison for AirT/RH measurements reported by the Vaisala Weather Transmitter (WXT) which also reports wind, barometric pressure and precipitation data.

At Buccoo Reef the analog AirT/RH sensor lasted 90 days before the RH data went bad on February 25, 2014.  [All instruments on a CREWS/CCCCC buoy are intended to produce usable data for an entire year.]  The buoy was offline due to a power failure from May 15 to August 11, 2014, and was brought briefly to land on November 12-13, 2014 and on February 2-3, 2015.  After the November 2014 maintenance operation both the AirT and RH data were bad, and as of this writing they are still bad.  An earlier post in this blog suggests that the AirT/RH sensor was "reinstalled" during the February 2015 maintenance operation and was at that time "working properly," but there is no hint of good data in the hourly data records from this time.

The following are graphs of AirT (top, in °C) and RH (bottom, in %) from the Buccoo Reef buoy's lifetime, from 2013 to the present.  Values reported from the analog sensor under discussion are in blue and values from the WXT are in red.  Data are shown through June 9, 2015.

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

Based on this data record the BUTO1 (Buccoo Reef) buoy's AirT/RH sensor performed reasonably well for 90 days out of the buoy's 469 operational days, or about 19% of the time.  Its longest stretch of proper operation was 90 days, or about 3.0 months.

Similar analysis performed on this buoy's sister stations at Speyside / Angel's Reef, Tobago (ARTO1) and Little Cayman, Cayman Islands (CCMI2) found that the ARTO1 instrument performed reasonably well for 181 days out of the buoy's 557 operational days, or about 32% of the time, and the CCMI2 instrument performed reasonably well for 376 days out of the buoy's 506 operational days, or about 74% of the time.  The ARTO1 sensor's longest stretch of proper operation was 181 days, or about 6.0 months, and the CCMI2 sensor's longest stretch of proper operation was 226 days, or about 7.4 months.

The complete analyses for the other AirT/RH sensors, including graphs, may be found at this link for ARTO1 and at this link for CCMI2.

(signed)
Mike Jankulak