Archive for May 30th, 2010

Cook plows forward

Sunday, May 30th, 2010

Cook is plowing into the head currents we saw in the previous post, and continuing to make good progress.  Cook is a fast glider, with a forward speed somewhere around 36 cm/sec.  Depth average currents are running just under 20 cm/sec.  In the image below, we see the glider currents (while flags along the track) line up well with the geostrophic currents from the altimeter.

And we see the same good agreement between the glider and the HyCOM model sea surface heights and surface currents.  With HyCOM we expect to cross into a burst of currents to the north, but according to the altimetry, it remains a head current.

If we switch to the Satellite sea surface temperature maps, we see a persistent region of cloud cover right over Glider Cook.  Why is that?

Switching on the clouds in google earth, we see a long line of clouds crossing the full North Atlantic.  If it is moving east, the sst imagery will start to fill in behind it with about a day or 2 delay. That will give us a good fresh look at the ocean surface.  So what is causing that long band of clouds?

For this we go to one one the Jet Stream forecast websites.  http://squall.sfsu.edu/crws/jetstream.html

Below is the present analysis with that long band of strong upper level winds running across the North Atlantic.

Overlaying that analysis on the visible cloud imagery, we see that that broad band of clouds is associated with the Jet Stream.  Our first lesson for the summer undergraduate internship program is now complete.