Archive for October 27th, 2009

CODAR update: PLOCAN Data

Tuesday, October 27th, 2009

Hello,

This week the CODAR group attempted to plot the data that we have acquired from PLOCAN in the Canary Islands. Unfortunately, things did no go as planned.

plocanAs you can see, the data has large gaps and follows no specific pattern. It is most likely a small error in the MATLAB code that is causing all of the data to plot incorrectly. Every minute of work is one step closer to achieving our goal. This week is going to be dedicated to debugging all of our plotting tools, including our CODAR scripts.

Another note, surface currents off the coast of Spain seem to be predominately North switching to East at various points throughout the day. The good thing is that surface current velocities in the area that we want RU27 to  complete its mission are well below 50 cm/s, mostly around 30cm/s, for the most of the day. This is very promising for our mission.

Thanks,

Mike and Lisa

Focusing on the Thermocline

Tuesday, October 27th, 2009

Hey everyone,

Over the past couple of days, the most noticeable change in the water column has been the thermocline position and strength.  On October 24th, the temperature change within the 35-80 meter displacement was very gradual.  There was no large change in decreasing water temperature within a small distance, as we have seen in the past.  However, this trend tends to fluctuate and it is difficult to predict how the thermocline will appear in the next couple of days; the plots shown below are the most recent example.  The CTD data from October 26th shows a large decrease in water temperature within barely 20 meters.

ctd-oct-24-therm

water column temp.-oct-26

As of this past week, bottom water temperatures have been hovering just above 13.5 degrees C. and there has been little change.  In addition, battery life is not too much of a concern relative to time because we have just below 50% left and bottom water temperatures do not seem to pose any threat either.  The main issue is dealing with the bio-fouling and slowing down barnacle growth. Staying below the thermocline, as well as the pycnocline, helps with limiting biology growth because we would be avoiding most of the nutrients.  Since the thermocline is constantly changing, our group will continuously keep track of the thermocline positions, as well as strength.  Also, we are continuing to look for some sort of archive of past underwater data for Spanish waters but the search continues.  RU27 is approaching the finish line and each group is working hard to get her to cross it.

-Colin and Abe