Causes of the Regional Variability in Observed Sea Level, Sea Surface Temperature and Ocean Colour Over the Period 1993–2011

Meyssignac, B; Piecuch, CG; Merchant, CJ; Racault, M-FLP; Palanisamy, H; MacIntosh, C; Sathyendranath, S; Brewin, RJW. 2016 Causes of the Regional Variability in Observed Sea Level, Sea Surface Temperature and Ocean Colour Over the Period 1993–2011. Surveys in Geophysics. 10.1007/s10712-016-9383-1

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Abstract/Summary

We analyse the regional variability in observed sea surface height (SSH), sea surface temperature (SST) and ocean colour (OC) from the ESA Climate Change Initiative datasets over the period 1993–2011. The analysis focuses on the signature of the ocean large-scale climate fluctuations driven by the atmospheric forcing and do not address the mesoscale variability. We use the ECCO version 4 ocean reanalysis to unravel the role of ocean transport and surface buoyancy fluxes in the observed SSH, SST and OC variability. We show that the SSH regional variability is dominated by the steric effect (except at high latitude) and is mainly shaped by ocean heat transport divergences with some contributions from the surface heat fluxes forcing that can be significant regionally (confirming earlier results). This is in contrast with the SST regional variability, which is the result of the compensation of surface heat fluxes by ocean heat transport in the mixed layer and arises from small departures around this background balance. Bringing together the results of SSH and SST analyses, we show that SSH and SST bear some common variability. This is because both SSH and SST variability show significant contributions from the surface heat fluxes forcing. It is evidenced by the high correlation between SST and buoyancy-forced SSH almost everywhere in the ocean except at high latitude. OC, which is determined by phytoplankton biomass, is governed by the availability of light and nutrients that essen- tially depend on climate fluctuations. For this reason, OC shows significant correlation with SST and SSH. We show that the correlation with SST displays the same pattern as the correlation with SSH with a negative correlation in the tropics and subtropics and a positive correlation at high latitude. We discuss the reasons for this pattern.

Item Type: Publication - Article
Additional Keywords: Sea level, Sea surface temperature, Ocean colour, Ocean heat content, Climate, ESA Climate Change Initiative, Wind forcing, Buoyancy forcing, ECCO reanalysis
Subjects: Earth Observation - Remote Sensing
Earth Sciences
Marine Sciences
Meteorology and Climatology
Oceanography
Divisions: Plymouth Marine Laboratory > Science Areas > Earth Observation Science and Applications
Depositing User: Marie-Fanny Racault
Date made live: 24 Nov 2016 11:30
Last Modified: 06 Jun 2017 16:17
URI: http://plymsea.ac.uk/id/eprint/7303

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