Date Awarded

2020

Document Type

Thesis

Degree Name

Master of Science (M.Sc.)

Department

Virginia Institute of Marine Science

Advisor

Elizabeth H Shadwick

Committee Member

Marjorie A. M. Friedrichs

Committee Member

Donglai Gong

Committee Member

Walker O Smith

Committee Member

Peter Sedwick

Abstract

Polynyas are large areas of open water or reduced sea ice coverage that persistently form in polar environments and often experience enhanced rates of physical, chemical, and biological processes that impact ocean dynamics on local to global scales. Polynyas that form adjacent to the coast, known as coastal polynyas, play an important role in the global carbon cycle by regulating the exchange of CO2 between the ocean and atmosphere in the high latitudes. Because of their importance to the global carbon cycle, there is a particular interest to better characterize CO2 system processes in Antarctic coastal polynyas. In this study, the inorganic carbon chemistry in three East Antarctic coastal polynyas - the Dalton Polynya, the Mertz Polynya, and the Ninnis Polynya - is investigated using a combination of ship-board water column and underway observations, remote sensing products, and model outputs. The first biogeochemical observations in the Dalton Polynya are presented, and the physical and biological controls on total dissolved inorganic carbon (TCO2) are examined. Despite the evidence of TCO2 depletion due to biological production, the surface waters of the Dalton Polynya were a weak net source of CO2 to the atmosphere during the summer survey. Satellite estimates of sea surface chlorophyll a concentration suggest that the shipboard observations were made prior to the peak of the productive season and are more likely representative of the transition between spring and summer. Compared to coastal polynyas, the rates of net community production and air-sea CO2 exchange in the Dalton polynya were relatively small.

DOI

http://dx.doi.org/10.25773/v5-8ghx-pe35

Rights

© The Author

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Oceanography Commons

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