Using 40 years of data from the Atlantic Ocean, combined with Met Office climate models, scientists at the Met Office Hadley Centre and the University of Reading’s Walker Institute for Climate System Research observed a significant increase in salinity in recent decades in the subtropical latitudes.

The increase is thought to be a consequence of rising evaporation and a decrease in rainfall, a scenario that is known to be affecting the salinity of land areas at the same latitudes, which, according to research undertaken last year, was due to human activity.

The findings, published in Geophysical Research Letters, may help climate experts to predict trends in rainfall, so that we can react accordingly. ‘Knowing how our oceans are changing over what are essentially vast data-sparse areas is important,’ said lead author Peter Stott, head of climate monitoring and attribution at the Met Office. ‘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.’

January 2009