Hola a todos !
first at all HAPPY B USA !! I wish you all to have a nice Fourth !!!

Enclosed find a little report of what has happened the last weekend. We suffered a great storm on saturday (figure 1)

Figure 1.- 2 of July 2011 (20:00 h). (EUMETSAT)

As expected (posted by Nilsen some days ago), the storm changed the current field around silbo 360 degrees in 24 hours (Figure 2). Silbo suffered an inertial wave, and this particular regime, changes the current direction in shorts, hourly periods, that only can be well reported with solid Regional ocean models- The good new however, is that on  monday morning the current changed to the W usual path observed since his deployment. However, current field is now flowing to the SW. Thats the main reason that we flew 11 km in some of the segments.

 

Figure 2. Silbo surfacings on weekend 2-3 jul 11.

The chl a maps also show two things: We are in a very dynamic area (eddies in the hole domain) and there is some jets, filaments flowing south that we could ride in the future to fly south (-rivers- at sea) …(figure 3)

Figure 3.- Chl a fields MODIS. 4 July 2011.

 

The “toast of the day” (Oscar dixit) goes to the But the toast goes to figures 4 and 5 (SSHa). A Topographic map of the ocean…with hills (warm eddies) and ponds (cold eddies).

Figure 4. SSHa field 4th July 2011.

 

It is shown the posisble rutes jumping from eddy to eddy to the bifurcation at south. At this moment we would have teo options to follow on: SE vs SW…But we would follow jumping from eddy to eddy (figure 5)…

Figure 5. SSHa 4 july 2011. (3D).

Another point of discussion is moving the waypoint a little bit to the west (we are slightly drifting E (23.7 W today). If we would move the WP we would get:

1.- To take advantage of the SW current field flowing now….

2.- Avoid the Silbo drifting to the E. It increases his resistance to the current reducing his speed. Moving to the W the WP, he would relax his navigation.

We wish you from the other side of the pond, Force wind, sea and honor USA.

Have a nice Fourth great team !

Antonio G.Ramos (University of las Palmas de Gran Canaria)