By Rita Markina
The UK OSNAP team left Southampton on 12 July and is heading into the sub-polar North Atlantic. We will be working on the very eastern part of the OSNAP line from the Hebrides shelf via the Rockall basin to the Iceland Basin. This is the region where two major branches of warm and salty Atlantic waters flow into the Arctic, and we have various different oceanographic equipment on board to measure these ocean currents.
Picture 1: Map in the main lab showing the expedition region with the current location of the ship, mooring stations, and Argo deployments sites (ship’s position is updated daily). Photo from Rita Markina.
We will recover and redeploy several moorings that have been recording ocean properties continuously since Oct 2020. We will do a bunch of CTD stations where we will measure vertical profiles of ocean temperature, salinity, oxygen, fluorescence, pH and current velocity, and sample water at different depths for sensor calibration and chemical analysis of carbon, oxygen and nutrients. Apart from this, we will deploy three biogeochemical Argo floats which will measure CTD profiles and at least three (pH, nitrate, chlorophyll) out of the six biogeochemical Argo parameters (oxygen, chlorophyll, BBP, nitrate, pH and irradiance). These parameters are important to assess ecosystem health. There is also a brand-new bottom pressure recorder on board that we will deploy. A second recorder will be installed at the western basin during M148 led by our German colleagues from GEOMAR in August. The bottom pressure data on either side of the Atlantic will allow us to estimate the amount of water transported between the two instruments. More on this measurement system and how it works here: https://www.sonardyne.com/ocean-bottom-pressure-data-unlocks-amoc/
While our ship is moving north, the crew, technicians and science team prepare all the equipment, and those of us who are here for the first time are familiarising ourselves with the ship – which looks gorgeous. Check it out with this virtual tour: https://noc.ac.uk/facilities/ships/rrs-james-cook/rrs-james-cook-virtual-tour.
This morning we saw the dolphins! They came really close to the ship – curious about what we are up to (or just enjoying the waves).
Picture 2. Dolphins following RSS James Cook in the Irish Sea. Video from Rita Markina.
More details about our work and life on board are soon to come!