MET OFFICE News
Release issued by COI News Distribution Service. 23 October 2008
Changes in the
salinity of our oceans are being brought about by man's
influence on our climate, suggests new research conducted by the
Met Office Hadley Centre and the Walker Institute for Climate
System Research at the University of Reading, to be published in
Geophysical Research Letters next month.
Using data from the Atlantic Ocean and Met Office climate model
simulations, the study reveals increasing salinity in the
sub-tropical zone - an indication of less rainfall and increased
evaporation. This mirrors decreased rainfall over land areas in
the same latitudes identified in previous research in 2007,
attributing this to human activity.
Saltiness of the oceans can help us to understand what the likely
drying and droughts on land might be in the future. Peter Stott,
head of climate monitoring and attribution at the Met Office and
leader of the study, explains: "Knowing how our oceans are
changing over what are essentially vast data-sparse areas is
important. It provides us with a window on changes in the
hydrological cycle and gives us more certainty in projections of
rainfall as the climate changes. In our region, for instance, this
research could help us to refine projections of summer drying
extending out from the Mediterranean basin."
Co-author Professor Rowan Sutton said: "The freshening of
polar waters in the Atlantic, which has raised fears about a
collapse of the warm Gulf Stream current, leading to a
significantly colder climate for Europe, looks not to be related
to increasing greenhouse gases, but natural variability."
The scientists used a Met Office climate model to simulate
variations in the Atlantic Ocean. In the north Atlantic recent
freshening, recorded before 2003, has been reversed. These changes
could be because of natural variability. However, in the
sub-tropics where the increased salinity was found to be outside
natural variability, the changes could only be attributed to
human-induced global warming.
ENDS
For further information contact Met Office Press Office 01392 886655
Notes to editors:
* The Met Office is the UK's National Weather Service,
providing 24x7 world-renowned scientific excellence in weather,
climate and environmental forecasts and severe weather warnings
for the protection of life and property.
* The Met Office Hadley Centre is the UK's foremost centre
for climate change research. Partly funded by Defra (the
Department for Environment, Food and Rural Affairs), the
newly-established Dept for Energy and Climate Change and the
Ministry of Defence it provides information to and advice to the
UK Government on climate change issues.
* The Walker Institute for Climate System Research was
established at the University of Reading in 2006. It draws
together a number of internationally renowned climate system
research groups and centres with expertise across a wide range of
core disciplines central to climate system science. Our vision is
to be a leader in integrated climate system research in order to
deliver better knowledge and understanding of future climate and
its impacts for the benefit of society.
* Professor Rowan Sutton is a Royal Society Research Fellow in
the Climate Division of the UK National Centre for Atmospheric
Science (NCAS) based in the Department of Meteorology at the
University of Reading. He is also a member of the Walker Institute
for Climate System Research at the University of Reading. He is
the Climate System Theme Leader at NERC, Head of the
Atlantic-European Climate Group and Member of the World Climate
Research Programme CLIVAR Atlantic Panel.