Monday, 11 February 2013

Why I'm here!

 Thought I ought to get round to a post about the work here. There are two strands, firstly we brought two ocean gliders down with us on the ship. In a break with tradition, we will take them both home again! The gliders are autonomous underwater vehicles, capable of staying out for up to three months. They communicate via iridium satellite so we can check on the data and update waypoints and flying parameters.

An ocean glider not in the ocean. Outside the Bonner lab to test satellite communications

 They don't have a propeller, instead moving by changing their density. They do this by moving a piston in and out at the nose to either sink or float. The vertical motion is partially turned to horizontal motion by the wings and moving a large battery in front of the wings - forward to tip the nose down, back to bring the nose up. This process makes them extremely efficient (3 months battery life) but also very slow (1km/hr)

About to deploy a glider off Sea Rover, before the winch got in the way (photo: Paul Samways)

 Glider in the water. We have deployed them on short missions close to base and also on longer trips away from the base.

Talking to the glider from a RIB to find out where it is before recovering it.

The other part of the work is checking the handover between Marine Assistants, who spend two summers and a winter on base collecting data from the bay and also diving to collect animals and deploy logging instruments. Mairi (above) is coming to the end of her stint. The final job is to bring live animals back to the UK in a transport aquarium on the ship.

This season is also the first of the Dutch collaboration so has seen a big increase in the amount of sampling in the bay. We've often had all three sampling boats out at once.

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