Hey All,

With Silbo now safely on shore and preparations being made  for his safe return to Teledyne Webb Research in Massachusetts, we now can focus solely on Challenger and her mission to cross the South Atlantic.

Now, just under 800 km from the southern shores of Ascension, we set our sights on what is seemingly the last stationary obstacle standing between Challenger and her destination: one last ridge of seamounts.  To prepare for their presence, we set a way point to the north of the island to account for the ~11˚ offset we have grown accustom to flying with over the past months, and with the way point being close to 900 km away we don’t have to worry about hitting it any time soon.

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One oddity we have noticed while flying past the previous subsurface mountain range was that there was a noticeable oscillation in the currents

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As there was little evidence in the surface current forecast to confidently say what was the cause of this, we delved deeper into the data and found two interesting clues:  the thermocline had deepened and we were flying slightly faster on dives than on climbs.

 

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Antonio pointed out that this was a similar flight scenario as to what a glider sees when crossing a strong warm eddy which sparked an idea in his mind.  To the south west of the island of Gran Canaria, there is an eddy that remains for the most part stationary in its location and is caused by drag as the currents flow through the island chain.

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Sea Surface Height

 

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Sea Surface Temperature

Now in our scenario, the sea mounts came within reach of the subsurface flight pattern of Challenger, but did not breach the surface as the islands of Gran Canaria and Tenerife do.  Because of this fact, this warm eddy that we believe we flew Challenger through would not have a signature at the surface and would cause the thermocline to be substantially deeper

Force Wind Sea & Honor