After pursuing the waypoint set at the end of last week through the weekend, Challenger has continued to see a consistent push to the north by the current. Late yesterday to try and better counter this force, the waypoint was shifter further east and slightly more to the south to try and have 29 hit the edge of the eddy at a nice angle to ride it around to the south when the glider reaches that point a little later this week.
In the RTOFS forecast, the model is showing the Challenger has nearly reached the edge of the elongated eddy and says that the current should now be flowing north to south-south east representing the south west sector of the warm eddy. However, the currents as they are reported by the glider seem to be going in the opposite direction flowing to the north with a little bit to the west.
In Copernicus, the model matches up much closer to the gliders report, showing a weak counter current to the rotation of the eddy whose presence is still a little ways away.
Over the past few days, Dave and Antonio have further discussed the change in vertical velocities seen by the glider over the past few months. Starting in October, the glider had seen more time at the surface due to the trouble shooting of the pump which needed to be done. This increased surface time then allows for a greater chance of successful settlement of larval stage organisms such as barnacles on the hulls.
If we are seeing the effects of biological growth on the gliders, combined with issues still being dealt with with the pump, it will build up a case to increase pitch angles (faster and less oddities for pump) and fly a little deeper, perhaps longer too in order to slow down the growth. Either way, we believe if we can complete the journey by April the glider should be in good shape
Force wind sea & honor