Sources, variability and fate of freshwater in the Bellingshausen Sea, AntarcticaSources, variability and fate of freshwater in the Bellingshausen Sea, Antarctica

Regan, Heather C.; Holland, Paul R. ORCID: https://orcid.org/0000-0001-8370-289X; Meredith, Michael P. ORCID: https://orcid.org/0000-0002-7342-7756; Pike, Jennifer. 2018 Sources, variability and fate of freshwater in the Bellingshausen Sea, AntarcticaSources, variability and fate of freshwater in the Bellingshausen Sea, Antarctica. Deep Sea Research Part I: Oceanographic Research Papers, 133. 59-71. 10.1016/j.dsr.2018.01.005

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Official URL: http://dx.doi.org/10.1016/j.dsr.2018.01.005

Abstract/Summary

During the second half of the twentieth century, the Antarctic Peninsula was subjected to a rapid increase in air temperatures. This was accompanied by a reduction in sea ice extent, increased precipitation and a dramatic retreat of glaciers associated with an increase in heat flux from deep ocean water masses. Isotopic tracers have been used previously to investigate the relative importance of the different freshwater sources to the adjacent Bellingshausen Sea (BS), but the data coverage is strongly biased toward summer. Here we use a regional model to investigate the ocean's response to the observed changes in its different freshwater inputs (sea ice melt/freeze, precipitation, evaporation, iceberg/glacier melt, and ice shelf melt). The model successfully recreates BS water masses and performs well against available freshwater data. By tracing the sources and pathways of the individual components of the freshwater budget, we find that sea ice dominates seasonal changes in the total freshwater content and flux, but all sources make a comparable contribution to the annual-mean. Interannual variability is dominated by sea ice and precipitation. Decadal trends in the salinity and stratification of the ocean are investigated, and a 20-year surface freshening from 1992-2011 is found to be predominantly driven by decreasing autumn sea ice growth. These findings will help to elucidate the role of freshwater in driving circulation and water column structure changes in this climatically-sensitive region.

Item Type:	Publication - Article
Digital Object Identifier (DOI):	10.1016/j.dsr.2018.01.005
ISSN:	09670637
Date made live:	01 Feb 2018 13:57 +0 (UTC)
URI:	https://nora.nerc.ac.uk/id/eprint/519200

Item Type:

Publication - Article

Digital Object Identifier (DOI):

10.1016/j.dsr.2018.01.005

ISSN:

09670637

Date made live:

01 Feb 2018 13:57 +0 (UTC)

URI:

https://nora.nerc.ac.uk/id/eprint/519200