NUI Galway is investigating how marine life can help reduce global warming, reports Lorna Siggins, Marine Correspondent
Scientists at NUI Galway are leading one of the largest international studies yet conducted into how microscopic marine plants may affect the global climate.
The three-year project, costing around €3 million, has deployed the State research vessel, Celtic Explorer, off the west and north-west coasts to find out how dense blooms of tiny plankton in the ocean may interact with, and enrich, bursting bubbles on the sea surface to form stable clouds that decrease global warming.
"Naturally forming aerosol particles form haze and cloud layers that can hide the effect of warming," says Dr Colin O'Dowd of NUI Galway's Environmental Change Institute and Department of Physics. "Quantifying the sources of aerosols and their global cooling effects will enable better future controls on greenhouse-gas emissions."
Dr O'Dowd and a team of scientists from Italy and Lithuania had first identified the phenomenon - whereby significant organic matter produced by the ocean is transferred into the atmosphere to produce a cooling effect - in a paper published in the science journal, Nature, in October 2004.
Aerosol particles are tiny airborne phenomena (about one millionth of a metre in size) which form haze and cloud layers. They are produced both naturally and by man-made emissions, and they block out a fraction of the solar energy which heats up our planet. The particles create brighter haze and cloud layers, which can reflect back more of the sun's energy and thus reduce the effects of global warming.
In the Nature paper, the scientists explained that much of the research into marine aerosols had focused on their production from sea salt and non-sea salt sulphates, but that this couldn't account for the entire aerosol mass.
They reported on measurements of physical and chemical properties in samples collected in the north-east Atlantic air, which were undertaken at NUI Galway's Mace Head research station in 2002. The Global Atmosphere Watch station at Mace Head in Co Galway has become a world-renowned research facility for such work.
The aerosol properties exhibited "clear seasonal patterns", following biological activity in the north Atlantic, they noted. They detected high chlorophyll concentrations from spring through to autumn, corresponding to the plankton blooming period in the north Atlantic, while there were minimum concentrations during the winter. During the bloom periods, they found that the organic fraction dominated and contributed 63 per cent to the sub-micrometre aerosol mass. In winter, when biological activity was at its lowest, the organic fraction fell to 15 per cent.
The scientists' model simulations indicated that organic matter could increase cloud droplet concentration by 15 per cent, to more than 100 per cent. They concluded that this organic matter was an important component of an aerosol/ cloud/climate "feedback system".
Dr O'Dowd and his department have assembled a team of 25 research groups from 20 research institutes in Europe and the US to engage in the three-year study, with funding from the European Commission and the Marine Institute.
The Marine Aerosol Production (Map) project, as it is called, will use NUI Galway's Mace Head station, along with the Marine Institute's research vessel, Celtic Explorer, and Nasa satellite sensors, to collect observations.
The ship has been deployed to work in areas of plankton bloom recently recorded off the west coast in images taken by Nasa satellites. It set sail on June 11th after a week of "mobilisation" works in the Cobh shipyard, Co Cork.
Four weeks of intensive data collection will be followed by two years of analysis to quantify the role of natural marine aerosol production in climate change. Marine Institute chief executive Dr Peter Heffernan said that the project highlighted Ireland's strategic importance as a "natural laboratory for studying the dynamics and impacts of climate change".