Variability in the freshwater balance of northern Marguerite Bay, Antarctic Peninsula: Results from δ18O

Meredith, Michael P., Brandon, Mark A., Wallace, Margaret I., Clarke, Andrew, Leng, Melanie J., Renfrew, Ian A. ORCID: https://orcid.org/0000-0001-9379-8215, van Lipzig, Nicole P. M. and King, John C. (2008) Variability in the freshwater balance of northern Marguerite Bay, Antarctic Peninsula: Results from δ18O. Deep-Sea Research Part II: Topical Studies in Oceanography, 55 (3-4). pp. 309-322. ISSN 1879-0100

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Abstract

We investigate the seasonal variability in freshwater inputs to the Marguerite Bay region (Western Antarctic Peninsula) using a time series of oxygen isotopes in seawater from samples collected in the upper mixed layer of the ocean during 2002 and 2003. We find that meteoric water, mostly in the form of glacial ice melt, is the dominant freshwater source, accounting for up to 5% of the near-surface ocean during the austral summer. Sea-ice melt accounts for a much smaller percentage, even during the summer (maximum around 1%). The seasonality in meteoric water input to the ocean (around 2% of the near-surface ocean) is not dissimilar to that of sea-ice melt (around 2% in 2002 and 1% in 2003), contradicting the assumption that sea-ice processes dominate the seasonal evolution of the physical ocean environment close to the Antarctic continent. Three full-depth profiles of oxygen isotopes collected in successive Decembers (2001–2003) indicate that around 4 m of meteoric water is present in the water column at this time of year, and around 1 m of sea-ice formed from this same water column. The predominance of glacial melt is significant, since it is known to be an important factor in the operation of the ecosystem, for example by providing a source of nutrients and modifying the physical environment to control the spatial extent and magnitude of phytoplankton blooms.The Western Antarctic Peninsula is undergoing a very rapid change in climate, with increasing ocean and air temperatures, retreating glaciers, and increases in precipitation associated with changes in atmospheric circulation. As climate change continues, we expect meteoric water inputs to the adjacent ocean to rise further. Sea-ice in this sector of the Antarctic has shown a climatic decrease, and we expect a reduction in oceanic sea-ice melt fractions if this change continues. Continued monitoring of the oceanic freshwater budget at the western Peninsula is needed to track these changes as they occur, and to better understand their ecological consequences.

Item Type: Article
Uncontrolled Keywords: sdg 13 - climate action,sdg 15 - life on land ,/dk/atira/pure/sustainabledevelopmentgoals/climate_action
Faculty \ School: Faculty of Science > School of Environmental Sciences
University of East Anglia Research Groups/Centres > Theme - ClimateUEA
UEA Research Groups: Faculty of Science > Research Groups > Centre for Ocean and Atmospheric Sciences
Faculty of Science > Research Groups > Marine and Atmospheric Sciences (former - to 2017)
Faculty of Science > Research Groups > Meteorology, Oceanography and Climate Dynamics (former - to 2017)
Faculty of Science > Research Groups > Climate, Ocean and Atmospheric Sciences (former - to 2017)
Depositing User: Rosie Cullington
Date Deposited: 25 Feb 2011 14:24
Last Modified: 20 Mar 2023 10:34
URI: https://ueaeprints.uea.ac.uk/id/eprint/24870
DOI: 10.1016/j.dsr2.2007.11.005

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