Hey All,
As we arrange for Challenger’s recovery on shore, our little glider continues progress towards Sao Miguel. However, the elements are proving to be relentless and refuse to let up.
Figure 1: Storm as of 11/11/11
Challenger is in the midst of yet another storm that has stirred up the seas causing an inertial oscillation near the surface that has been pushing him around. Because we are now diving to 300m to avoid the intense pressures at depth that have caused our previous two leaks, we are now more likely to be effected by the storm as we are spending more time in waters towards the surface.
Figure 2: Challenger 1 making good progress despite a storm
To help combat any inertial oscillations and to get us back towards shore as fast as possible, we have been flying with full buoyancy. Flying at the higher intensity, although keeping us flying relatively straight, is very inefficient energy wise and so we have turned it off as of this afternoon. Because of this we will most likely see more of a drift to the north as we get pushed by the currents.
Figure 3: Challenger 1: just over 100km from the Port of Ponta Delgada
Below we have a dissection of the water column provided by Antonio and ULPGC, showing the currents (Figure 4) and the North-South components (Figure 5) at the surface, 100m, 200m and 300m depths. Below that in Figure 6 we see a nice association between the movement on the surface waters and the sea surface height (and continuing correlation at depth).
Figure 4: Currents around The Azores at the Surface, 100m, 200m and 300m depths
Figure 5: N-S flow at the Surface, 100m, 200m and 300m depths
Figure 6: Sea Surface Height with the Surface Currents overlayed
Another fascinating point is that beginning a few days back, Challenger discovered a patch of very salty water at depth, depicted by the orange blob in the bottom right corner of Figure 7. This is the outflow of water from the Mediterranean. Water in the Mediterranean has a much higher level of salinity due to higher levels of evaporation than fresh water inputs. This water then can be traced as it flows into the North Atlantic for thousands of kilometers. In Figure 8 and 9, we have Sea Salinity at the Surface, 200m, 500m, 800m, 900m, 1000, and 1200m courtesy of Antonio and ULPGC.
Figure 7: Salinity Data Collected by Silbo. Beginning with early November there is a strong anamoly at depth
Figure 8: Salinity at Surface, 200m, 500m, and 800m
Figure 9: Salinity at 900m, 1000m, 1200m and Time Series from Challenger's Journey
Finally, I would just like to mention what our current plan is for recovery of our brave little droid. As we are in the North Atlantic in the middle of storm season, there are windows that are ideal and ones that are not. We had an original window we were looking at of Saturday the 12th (tomorrow) where the forecast called for clear skies and relatively calm seas. However, finding a boat, facilities and plane tickets out to the Azores can be difficult (especially on such short notice), and so the next reasonable meteorological window that allowed us to get access to all of the resources needed lands us on Wednesday Nov. 16th. The recovery team will be leaving the Port of Ponta Delgada, Sao Miguel where the 32 ft fishing boat, Alabote (seen in Figure 10) is available to us. Time of departure will be decided when we get closer to the mission, but when the team returns to land, Challenger will get checked out and hopefully be able to be put back in the water as soon as possible.
Figure 10: Alabote Fishing Boat
The recovery will hopefully not take too long to sail out and back as by Wednesday we wont be too far off shore. As of this evening, Challenger is 97km from shore
Figure 11: Challenger's progress towards recovery. 97km and 5 days away from recovery
As always Force Wind Sea and Honor all and especially to Challenger
Lauren Cooney, Antonio Ramos & Nilsen Strandskov