Station back Online

The La Parguera ICON station is back online following the removal of an underwater light sensor by Wess Merton of UPR. This means that all told the station was offline for about eleven and a half days. The removal of the "deep" light sensor appears to have solved the power problems and the station has in fact recharged itself much more quickly than expected. In addition, all other instruments on the station appear to have returned to their prior states of operation. That is to say, other than the two sensors which were known to be malfunctioning (the acoustic wind sensor on the Vaisala Weather Transmitter, and the pressure sensor on the Falmouth "shallow" CTD), all station electronics appear to have survived this adventure unscathed.

As a reminder, the timeline of the station's failure and recovery is as follows:

• Wednesday, April 14th: last station transmission sent at 11:22pm local time.
• Monday, April 19th: remote analysis suggests that the station has lost power due to the failure of its deep light sensor. Parts required for removal of the instrument are shipped to UPR from AOML.
• Friday, April 23rd: the failed light sensor is removed.
• Tuesday, April 27th: first post-recovery transmission is received at 2:22pm local time.

The station's battery levels normally oscillate between about 12.7 V (nighttime lows) and 13.9 V (daytime highs). Right now (see graph at right, which shows hourly battery levels over the past month) the battery levels are still low but they are recovering a little every day and are expected to return to normal levels after a few more weeks.

CREWs Deep BIC removal on April 23rd

On Friday April 23rd I went out and removed the Deep BIC as requested. Below are photos from the morning. The first is the sensor prior to removal.



In this photo the sensors cable had been removed from the spar by cutting the cable ties holding it in place. The deep CTD was wound up in the same orientation as the Deep BIC; this instruments cable was fixed back to its original position prior to the maintenance. Once the Deep BIC's cable was loose, the sensor was removed by unscrewing the two screws at the end of the mount.



Once at the surface, the sensor was gently laid on its side on a towel while I carefully removed the biofouling that had colonized the cable. Some mussels had managed to grow near the interface between the cable and the sensor possibly allowing a mode of entry for water to the sensor. After the biofouling was removed the cable was unplugged from the sensor and a female adapter plug was placed on the end of the sensors cable. This cable was wound up and placed on the spar as depicted in the photo below.