Scientists from the National Oceanography Centre (NOC), the University of Liverpool, Plymouth Marine Laboratory and the University of East Anglia will be examining why ocean temperatures are rising within the tropics and mid-latitudes of the North Atlantic, but at the same time are decreasing at the ocean′s high latitudes.
The research team (led by Dr Elaine McDonagh from NOC) are departing on a research cruise from Bermuda to establish the extent of the most recent temperature changes. During the 45-day expedition across the ocean RRS Charles Darwin will be stationed every 50km to take full ocean depth measurements. Instruments will be lowered through the water column, collecting data from the surface waters to the ocean floor, down to 6,000m (about 4 miles) in the deepest parts of the Atlantic.
At each station physical properties such as water velocity, temperature and salinity will be measured and a variety of biological and chemical samples will be collected. These include nutrients which carbon absorbing plants need to grow, the greenhouse gas carbon dioxide, and CFCs that act as tracers showing movement of water masses. Some 150 full ocean depth stations will be worked throughout the cruise.
The cruise forms the second component of a large UK experiment to examine the current role of the North Atlantic subtropical gyre in global climate regulation. The potential of the region to store heat and carbon dioxide and to assimilate carbon dioxide by plankton growth will be assessed by combining the results with similar observations from a cruise conducted on RRS Discovery the same time last year at 26°N, and from a 1981 cruise. The cruise will identify the ocean transport of heat, nutrients and carbon through the North Atlantic Ocean - improving our understanding of how the ocean has warmed over the last two decades, how phytoplankton grow and how the oceans absorb CO2.
The research is funded by the Natural Environment Research Council (NERC) through a Consortium grant.
National Oceanography Centre, Southampton press release
University of Liverpool press release