10 June: underway with Toby Sherwin

The D340 blog

Day 1 (Wednesday, June 10th 2009)

Well, here I am back on RRS Discovery for another Extended Ellett Line cruise from Iceland to Scotland via the most remote small rock in any ocean, Rockall.  This research cruise, funded by UK NERC’s Oceans2025, will measure and record the ocean temperature, salinity, oxygen and many other parameters across the north-east Atlantic’s gateway to the Nordic Seas and Arctic Ocean.  The surface waters that we shall cross carry a huge quantity of heat north-eastwards towards northern Europe and help to moderate its climate (even if much of this moderating ‘heat’ is in the form of moisture and rain).  The bottom waters carry the cold return flow from the north that helps to drive the circulation of the world ocean and hence control climate on a global scale.
Since 1975 we have observed that the surface waters of our part of the Atlantic have warmed by about 1° C.  This is much faster than for the Earth as a whole, which has taken about a century to warm by the same amount.  Some of the local warming is due to the global rise, but over half can probably be accounted for by the shifting patterns of circulation in the Atlantic.  It is through cruises such as this that we continue to learn about how fast the Earth’s surface is warming, and also how the ocean circulation is changing.
On board we have 28 scientists and technicians supported by a very experienced ship’s crew.  Some of the scientists are old seagoing hands, whilst others are coming to sea for the first time, some as undergraduate trainees and others as PhD students (the powerhouses of modern science) acquiring vital data for their research.  In the next 16 days a large number of us will record our experiences on Discovery and provide a flavour of what it is like to undertake scientific research on a large multidisciplinary cruise such as this. 
When we reach Scotland on June 26 there will be a major changeover of scientific staff who will undertake further research closer to the Scottish coast.

Toby Sherwin, Principal Scientist, Scottish Association for Marine Science.


The Extended Ellett Line track overlaid on a MODIS satellite image of the average chlorophyll a concentrations over the week before the start of cruise D340.  Courtesy of the PML Remote Sensing Group.