Archive for October 9th, 2009

Friday Night Fleet Check

Friday, October 9th, 2009

Its 10 o'clock.  Do you know where your fleet is?

A quick check of the global view shows we have gliders on both sides of the storm that is currently stirring up the North Atlantic.

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Nilsen reminds us that the storm is on its way towards The Scarlet Knight.  Oceanweather has wave heights (image below) over 20 feet high behind the cloud front in the image above.  We also see a small hotspot of wave activity back home in the Middle Atlantic Bight.

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These waves are currently effecting the MAB regional fleet.  RU22 is the IOOS glider heading south for pick up by the University of Maryland.  Its on a mission to collect IOOS water column data to compare with National Marine Fisheries Service shipboard survey of fish distributions. RU23 remains to the north on the Tuckerton Endurance line on a Navy mission.  RU23 has the new lithium rechargable batteries, and its carrying one of the new Seabird pumped CTDs on what we think is its first at sea test on a glider.  We are gathering data for the upcoming European Glider Organization (EGO) meeting in Cypress next month.

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Looking south, Drake continues heading north.  Once we reach about 25.5 N, we'll turn more towards the Northeast and continue to 26.5 N.  There we'll head east along a mooring array being maintained by the British designed to measure the heat flux across 26.5 N.

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One benefit of having students from our European partners in the Azores and Canaries is local knowledge. They found us an excellent website posting the Automated Information Service (AIS) vessel tracking data. Our students have starting watching this regularly, and have found heavy shipping traffic along the coasts of Portugal and Spain that extends offshore beyond the designated shipping lanes.  Lisa grabbed one of the snapshots from today and put it in google earth.   The vessel traffic is intense.

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Mike also put the live feed from the Galicia CODAR surface current vectors into google earth, and here is overlayed on the AIS ship traffic. The conclusion is clear.  Even though the full field of CODAR surface current vectors (shown in white) extends beyond the shipping lanes, so does the vessel traffic. Even this highly sampled region does not appear safe for RU27.

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That moves our primary target location to be even further offshore.   Zooming out to view the satellite altimetry, our goal now becomes first crossing the remaining 585 km to the outer edge of the European EEZ (the thin yellow arc), and then slowing moving closer in, loitering in the outer half of the EEZ until we can be reached for pick up by our friends at Puertos del Estando.

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Zooming in further, Scarlet is reporting currents in excellent agreement with the geostrophic currents observed in the satellite altimeter data.  It looks like we'll be getting a boost to the east over the weekend.  Thats encouraging news.  Scarlet's vertical velocity continues to drop, likely indicating the growth of a new set of barnacles that is slowing her down.  We won't know for sure until we see her again.   Till then, we need to fly her as fast as we can, and keep her as deep and cold as we can.  We dropped the depth of the surface inflection down from 20 m to 30 m already today.  We checked the number of cycles on the buoyancy pump to see if we want to risk even more cycles at the deeper depths.  And we increased the pitch on both upcast and downcast by a few degrees as a test to see what happens.  We may use more battery at this pitch, but we have over half the battery life left based on the theoretical calculations of the energy on board and the actual measured usage by the coulomb meter.

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