nerc.ac.uk

Assessing recent air-sea freshwater flux changes using a surface temperature-salinity space framework

Grist, Jeremy P.; Josey, Simon A.; Zika, Jan D.; Evans, Dafydd G.; Skliris, Nikolaos. 2016 Assessing recent air-sea freshwater flux changes using a surface temperature-salinity space framework. Journal of Geophysical Research: Oceans, 121 (12). 8787-8806. 10.1002/2016JC012091

Before downloading, please read NORA policies.
[img] Text (Open Access paper)
Grist_et_al-2016-Journal_of_Geophysical_Research__Oceans.pdf - Published Version
Restricted to NORA staff only
Available under License Creative Commons Attribution 4.0.

Download (1MB) | Request a copy
[img] Text
GristetalCLAW_Rjgrv.pdf - Submitted Version
Restricted to NORA staff only

Download (6MB) | Request a copy

Abstract/Summary

A novel assessment of recent changes in air-sea freshwater fluxes has been conducted using a surface temperature-salinity framework applied to four atmospheric reanalyses. Viewed in the T-S space of the ocean surface, the complex pattern of the longitude-latitude space mean global Precipitation minus Evaporation (PME) reduces to three distinct regions. The analysis is conducted for the period 1979-2007 for which there is most evidence for a broadening of the (atmospheric) tropical belt. All four of the reanalyses display an increase in strength of the water cycle. The range of increase is between 2%-30% over the period analysed, with an average of 14%. Considering the average across the reanalyses, the water cycle changes are dominated by changes in tropical as opposed to mid-high latitude precipitation. The increases in the water cycle strength, are consistent in sign, but larger than in a 1% greenhouse gas run of the HadGEM3 climate model. In the model a shift of the precipitation/evaporation cells to higher temperatures is more evident, due to the much stronger global warming signal. The observed changes in freshwater fluxes appear to be reflected in changes in the T-S distribution of the Global Ocean. Specifically, across the diverse range of atmospheric reanalyses considered here, there was an acceleration of the hydrological cycle during 1979-2007 which led to a broadening of the ocean's salinity distribution. Finally, although the reanalyses indicate that the warm temperature tropical precipitation dominated water cycle change, ocean observations suggest that ocean processes redistributed the freshening to lower ocean temperatures.

Item Type: Publication - Article
Digital Object Identifier (DOI): 10.1002/2016JC012091
ISSN: 2169-9291
Additional Keywords: Precipitation; Evaporation; Global Ocean; Temperature-Salinity; Atmospheric Reanalysis
Date made live: 15 Sep 2016 11:01 +0 (UTC)
URI: http://nora.nerc.ac.uk/id/eprint/514506

Actions (login required)

View Item View Item

Document Downloads

Downloads for past 30 days

Downloads per month over past year

More statistics for this item...