Archive for June 17th, 2010

Learning MATLAB

Thursday, June 17th, 2010

After a crash course in MATLAB from John yesterday, we started the morning by pulling the newest data file from Cook and plotting it in MATLAB. The blue and yellow show the down casts and the red and cyan show the up casts.

June 17, 2010 Depth v. Temperature

This plot is a Depth versus Temperature from Cook's last up and down casts. It shows the surface temperature being around 30 degrees Celsius and declining with depth to a minimum of 5 degrees Celsius. The thermocline can be seen from about 200m to 600m.

June 17, 2010 Depth v. Salinity

This is a plot of Depth versus Salinity from Cook's last up and down casts. The surface salinity is 36.35 psu and the salinity at 1200m is 34.6 psu. The halocline appears around 200m and extends down to about 900m.

June 17, 2010 Surface Salinity

While analyzing our plots we came across something that doesn't look quite right. We had some questions as to why the upper 40m of the salinity plot.  We think this could be due to Cook's current flight pattern which would not allow the sensors to have the right flow through them to provide accurate data.

June 17, 2010 Depth v. Density

This is the plot for Depth v. Density for Cook's last up and down casts. The density at the top is around 1023.5 Kg/m^3. The density decreases with depth to a density of 1032.5 Kg/m^3 at a depth of 1200m.

We will continue to plot CTD data for Cook and will be having another lesson from John today in order to learn to plot the HyCom data.

Cook May See an Unmarked Eddy

Thursday, June 17th, 2010

From Cook's data it appears to be in a clockwise eddy, however the Altimetry says that it should be in a counterclockwise eddy.

The HyCOM data says that the currents are southward and nearly perpendicular to eastward currents reported by Cook. The differences in the information provided by Cook, the Altimetry, and the HyCOM make this an interesting area to examine with the glider.