Through the weekend Challenger continued to fly towards the waypoint assigned towards the end of the week at 35˚30S, 4˚W.  With the current correction off, this allowed the glider to ride the northward flux along the arcing red path proposed in the previous post.

RU29_20151207_RTOFS

There is a counter clockwise eddy in both RTOFS (green) and copernicus (yellow)
in nearly the same locations.  In the figure above, the oval RTOFS eddy is outlined in green, and the perfectly round copernicus eddy is outlined in yellow.

RU29_20151207_Copernicus
In the two figures above, the straight green line is the line straight to Cape Town.
We want to keep RU29 between the straight red line to the south and the straight orange line to the north, while keeping as close to the green line as possible.

The waypoint decision we made last week revolved around how to approach the eddy near the Prime Meridian prominent in both models.  We had 2 options, the northern curved route (red) or the southern curved route (orange). The glider currents were persistently pushing us north and the currents along the northern track were consistent through both models, so we made the decision to go with this flow, and pursue a track along the northern red line.

ru29_20151207
For the foreseeable future, the bathymetry looks unobtrusive so as Challenger continues across the Prime Meridian (for the third crossing of the Challenger mission) and on towards Cape Town, we can rest easily when it comes to dodging sea mounts.

And finally below we have a field of the locations of the Argo floats that lie ahead.  Through the remainder of the mission we will attempt at approaching at least a few of these sampling devices for comparison and quality control purposes.

RU29_20151207_2100km_argo

Force Wind Sea & Honor