Upgrade to the PAP Observatory

November, 2020

In challenging conditions the team aboard RRS Discovery have upgraded the Porcupine Abyssal Plain Sustained Observatory (PAP-SO) with a new surface buoy. The upgrade should provide a more reliable platform for our long-term monitoring and provides opportunities to develop our capability to look at new scientific questions at the observatory in the future.

This upgrade is the result of a collaboration between several teams at the National Oceanography Centre and the UK Met Office. The new surface buoy provides meteorological data from sensors on its mast, oceanographic data from sensors on the keel and carbon dioxide is measured using a sensors in air and in the water. As the new platform becomes more established we will be able to add to its payload with more innovative sensors.

Connecting up the final sensors inside the keel before deployment. The deployment of the new buoy was a major objective of DY116. This cruise had been planned for much earlier in the year, when weather conditions are more favourable. Putting such a large piece of equipment over the side of the ship requires calm seas. Like so many things in 2020, the research cruise programme was not able to go as planned.

The conditions through November in the North East Atlantic have been far from ideal. We have spent quite a bit of this cruise avoiding the worst of the weather. The strongest winds and biggest waves seemed to be sitting right over the PAP-SO area for several weeks. Recently though, we have been seeing some improving weather and through careful planning and maximising the less favourable weather windows whenever possible, the team were ready as soon as an extended period of calmer sea conditions arrived.

Safe deployment of a large mooring like the PAP-SO surface buoy takes preparation and team work.

The weather window we had been watching turned out to be remarkable calm for November. The sun was even shining for part of the day and the calm seas held just long enough to successfully deploy the new mooring. This not only involved putting the buoy in the water but also required putting out the >5000 m of rope and anchor that keep it in position through the year.

We have a reduced sensor package on the system for its first deployment but on the next cruise to PAP-SO in 2021 the full package will return. The provides near real-time data and the science team are very excited to see the first few data points from this deployment are already coming in.