Iceberg-induced changes to polynya operation and regional oc
Details of Research
TitleIceberg-induced changes to polynya operation and regional oceanography in the southern Ross Sea, Antarctica, from in situ observationsAbstractTwo massive tabular icebergs calved from the Ross Ice Shelf in 2000 (B-15) and 2002 (C-19) and perturbed regional ocean processes for several years. Here we document the ocean's response in McMurdo Sound to the icebergs using in situ data collected before, during and after the icebergs Ìresidence in the Ross Sea. Departures from typical McMurdo Sound seasonal oceanography included the non-appearance of Antarctic Surface Water in summer, a cooler and more homogeneous water column during winter and Å›uper-fresh ÌHigh Salinity Shelf Water that gradually recovered its salinity. We found that each iceberg triggered a distinct response to regional ocean processes. B-15a, the largest piece of iceberg B-15, restricted surface circulation, cooled and freshened the upper water column and reduced melting near the ice shelf front for four years. Iceberg C-19 interrupted the operation of the Ross Sea polynya, from which McMurdo Sound took three to four years to recover, and was responsible for a geographic shift in the dense water formation region for the south-western Ross Sea. These results differ from earlier modelling studies and highlight the challenges of modelling the polar ocean. We also show that one pathway previously thought to supply dense water to the Ross Ice Shelf cavity was not operating at that time. Copyright Copyright 2012 Antarctic Science Ltd.AcknowledgementsThe authors gratefully acknowledge the generous provision of datasets by Nicole Albrect, Craig Stevens, Lionel Carter, Christina Cheng, Greg Leonard, and Andy Mahoney. Logistical support was provided by Antarctica New Zealand through events led by Tim Haskell and Alex Pyne. We wish to thank the anonymous reviewer for their thoughtful review and positive comments. Valuable comments on previous versions of this manuscript have been made by Stan Jacobs, Claudia Guilivi, Craig Stevens, Pat Langhorne and Inga Smith. The work was funded through a University of Otago Postgraduate Scholarship and the New Zealand Foundation for Research, Science and Technology.
TypeArticleCitationRobinson, N. and Williams, M. (2012). Iceberg-induced changes to polynya operation and regional oceanography in the southern Ross Sea, Antarctica, from in situ observations. Antarctic Science, 24(5): 514-526
Antarctica NZ (26th Nov 2018). Iceberg-induced changes to polynya operation and regional oc . In Website Antarctica NZ. Retrieved 29th Sep 2020 07:28, from https://adam.antarcticanz.govt.nz/nodes/view/63739