Abstract
dc:description.abstractGlacier-ocean interactions in shallow-silled fjords play a crucial role in the mass balance of marine-terminating glaciers and the transport of freshwater from the ice sheet to the ocean. Despite their importance, the complex dynamics of these systems, influenced by sill processes, freshwater inputs, and external forcing, are not well understood. This dissertation investigates the impact of these factors on fjord circulation, water properties, and submarine melting using a combination of numerical simulations and observational analysis. ☐ Idealized simulations, employing a coupled plume-ocean model, reveal distinct circulation regimes depending on the ratios of sill depth, fjord depth, and meltwater plume depth. The presence of a shallow sill reduces deep-fjord temperature and stratification near the glacier, with the reduced stratification often resulting in higher submarine melting rates. Observational analysis of the rapidly retreating Jorge Montt Glacier in Patagonia highlights the role of sill processes in modulating freshwater transport and fjord properties, with freshwater flux estimates revealing a seasonal cycle in runoff and meltwater flux varying out of phase with runoff. Submarine melt rates strongly correlate with fjord temperature and stratification. Further simulations demonstrate the key role of along-fjord wind forcing in driving circulation and melt processes, with down-fjord winds intensifying the exchange flow and heat transport towards the glacier, and both wind directions decreasing ambient stratification near the glacier front. ☐ The findings of this dissertation contribute to a better understanding of the complex interplay between sill processes, freshwater inputs, stratification, and external forcing in modulating glacier-ocean interactions in shallow-silled fjords. The insights gained from this work have important implications for accurately representing these processes in models of tidewater glacier systems and predicting the response of marine-terminating glaciers to oceanic forcing. By providing a framework for understanding the key mechanisms driving glacier-ocean interactions in these systems, this research contributes to more accurate projections of ice loss and sea-level rise in the face of a changing climate.
Degree
thesis:*- Grantor dc:publisher
- University of Delaware
- Year dc:date.issued
- 2024
Author and committee
dc:creator, dc:contributor.*- Author dc:creator
-
- Bao, Weiyang
Subjects
dc:subject × 5Identifiers
dc:identifier.*- OAI identifier oai:identifier
- oai:udspace.udel.edu:19716/35444