Date of Award

2015

Degree Type

Thesis

Degree Name

Master of Science in Oceanography

Department

Oceanography

First Advisor

Brice Loose

Abstract

In ice-covered regions it can be challenging to determine air-sea exchange - for heat and momentum, but also for gases like carbon dioxide and methane. The harsh environment and relative data scarcity make it difficult to characterize even the physical properties. Here, we seek a mechanistic interpretation for the rate of air-sea gas exchange (k) derived from radon-deficits. These require an estimate of the water column history extending 30 days prior to sampling. We used coarse resolution (36km) regional configuration of the MITgcm with fine near surface vertical spacing (2m) to evaluate the capability of the model to reproduce conditions prior to sampling. The model is used to estimates sea-ice velocity, concentration and mixed-layer depth experienced by the water column .We then compared the model results to existing field data including satellite, moorings and Ice-tethered profilers. We found that sea-ice coverage have 88 to 98% accuracy, sea-ice velocities have 78% correlation which resulted in 2 km/day error in 30 day trajectory of sea-ice. Model showed the capacity to capture mixed layer evolution trends although with a bias and water velocities showed only 29% correlation with actual data. Using the capacity of the model to produce same order of magnitude of water speed we calculated an average radius of possible origins of water parcel equal to 10.3 km.

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