title: Global water cycle amplifying at less than the Clausius-Clapeyron rate.
abstract: A change in the cycle of water from dry to wet regions of the globe would have far reaching impact on humanity. As air warms, its capacity to hold water increases at the Clausius-Clapeyron rate (CC, approximately 7% °C-1). Surface ocean salinity observations have suggested the water cycle has amplified at close to CC following recent global warming, a result that was found to be at odds with state-of the art climate models. Here we employ a method based on water mass transformation theory for inferring changes in the water cycle from changes in three-dimensional salinity. Using full depth salinity observations we infer a water cycle amplification of 3.0 ± 1.6% °C-1over 1950-2010. Climate models agree with observations in terms of a water cycle amplification (4.3 ± 2.0% °C-1) substantially less than CC adding confidence to projections of total water cycle change under greenhouse gas emission scenarios.
authors.affiliation: University of Southampton, National Oceanography Centre, Southampton, UK.
authors.forename: Nikolaos
authors.initials: N
authors.lastname: Skliris
authors.affiliation: School of Mathematics and Statistics, University of New South Wales, Sydney, Australia.
authors.forename: Jan D
authors.initials: JD
authors.lastname: Zika
authors.affiliation: National Oceanography Centre, Southampton, UK.
authors.forename: George
authors.initials: G
authors.lastname: Nurser
authors.affiliation: National Oceanography Centre, Southampton, UK.
authors.forename: Simon A
authors.initials: SA
authors.lastname: Josey
authors.affiliation: University of Southampton, National Oceanography Centre, Southampton, UK.
authors.forename: Robert
authors.initials: R
authors.lastname: Marsh