The Effect of Arctic River Hydrological Cycles on Arctic Ocean Circulation

<p>Understanding Arctic Ocean circulation may be critical to fully understanding the global oceanic salt and heat cycles and their response to climate variability. This thesis examines how one important aspect of Arctic Ocean circulation, the effect of freshwater inflow, may contribute to the variability of these cycles. The multiple roles that freshwater runoff performs in the Arctic Ocean include: (1) the formation of shelf and basin scale density currents; (2) maintenance of the strong density stratification; (3) control of the thickness and strength of the ice pack; and (4) control of deep convection. Sources and sinks of freshwater in the Arctic include: shoreline discharge as point and non-point runoff; influx through Bering, Fram and/or other straits; permafrost erosion; precipitation; formation and melting of glacial and sea ice shelf mixing and efflux through Fram Strait and the Canadian Archipelago. With newly acquired data, the annual runoff discharge cycle for most of the Arctic rivers for the 50 years up to 1987 and the Bering Strait freshwater flux for the years from 1943 to 1987 have been quantified. For the period 1973 to 1987, where data for most Arctic rivers overlap, the estimated mean annual discharge is 2646 km³$ yr^-1 with a standard deviation of 150 km³ yr^-1 and a coefficient of variation of 0.06.</p> <p>Understanding the effect of freshwater inflow is necessary because variation in annual inflow of freshwater to the Arctic could impact deep convection in the northern North Atlantic. The data has been utilized in a numerical model of the Arctic mixed layer to establish a residence time for freshwater in the Arctic and to explain the ambiguity of previous residence times derived from tracer studies. The model results show that the freshwater outflow from the Arctic Ocean is generally insensitive to small observed interannual variations in Arctic freshwater inflow, but that a large enough variation may be a part of the conditions for the production of surface salinity anomalies in the northern North Atlantic.</p>

Name thesis:degree_name

Doctor of Philosophy (PhD)

Level thesis:degree_level

Dissertation

Discipline thesis:degree_discipline

Ocean & Earth Sciences

Year dc:date.available

1995

Author dc:creator

• Becker, Peter

Contributors dc:contributor

• Larry P. Atkinson
• A. D. Kirwan, Jr.
• John M. Klinck
• Sydney Levitus

• Ocean circulation
• Runoff
• Hydrology
• Oceanography

Statement dc:rights

• <p>In Copyright. URI: <a href="http://rightsstatements.org/vocab/InC/1.0/">http://rightsstatements.org/vocab/InC/1.0/</a> This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. For other uses you need to obtain permission from the rights-holder(s).</p>

Repository record dc:identifier

https://digitalcommons.odu.edu/oeas_etds/29

OAI identifier oai:identifier

oai:digitalcommons.odu.edu:oeas_etds-1026