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On the stability and spatiotemporal variance distribution of salinity in the upper ocean


O'Kane, TJ and Monselesan, D and Maes, C, On the stability and spatiotemporal variance distribution of salinity in the upper ocean, Journal of Geophysical Research: Oceans, 121, (6) pp. 4128-4148. ISSN 2169-9275 (2016) [Refereed Article]


Copyright Statement

Copyright 2016 American Geophysical Union

DOI: doi:10.1002/2015JC011523


Despite recent advances in ocean observing arrays and satellite sensors, there remains great uncertainty in the large-scale spatial variations of upper ocean salinity on the interannual to decadal timescales. Consonant with both broad-scale surface warming and the amplification of the global hydrological cycle, observed global multidecadal salinity changes typically have focussed on the linear response to anthropogenic forcing but not on salinity variations due to changes in the static stability and or variability due to the intrinsic ocean or internal climate processes. Here, we examine the static stability and spatiotemporal variability of upper ocean salinity across a hierarchy of models and reanalyses. In particular, we partition the variance into time bands via application of singular spectral analysis, considering sea surface salinity (SSS), the Brunt Väisälä frequency (N2), and the ocean salinity stratification in terms of the stabilizing effect due to the haline part of N2 over the upper 500m. We identify regions of significant coherent SSS variability, either intrinsic to the ocean or in response to the interannually varying atmosphere. Based on consistency across models (CMIP5 and forced experiments) and reanalyses, we identify the stabilizing role of salinity in the tropics—typically associated with heavy precipitation and barrier layer formation, and the role of salinity in destabilizing upper ocean stratification in the subtropical regions where large-scale density compensation typically occurs.

Item Details

Item Type:Refereed Article
Keywords:salinity, ocean, large-scale spatial variations,
Research Division:Earth Sciences
Research Group:Oceanography
Research Field:Chemical oceanography
Objective Division:Environmental Management
Objective Group:Marine systems and management
Objective Field:Oceanic processes (excl. in the Antarctic and Southern Ocean)
UTAS Author:O'Kane, TJ (Dr Terry O'Kane)
ID Code:118378
Year Published:2016
Web of Science® Times Cited:13
Deposited By:Directorate
Deposited On:2017-07-11
Last Modified:2017-10-17
Downloads:150 View Download Statistics

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