PhD Thesis Proposal: Larson Kaidel

"Observations of Sea Ice Properties and Drift at Geophysically Relevant Scales"

Abstract

An icy world sitting at the top of our planet, evolves rapidly and consequently as a result of anthropogenic climate change. The highly variably sea ice cover is instrumental in the complex, fragile system of the Arctic. Quantifying material properties of sea ice at a range of scales from small (μm) to large (km) is necessary to accurately represent its role in the Arctic system. Furthermore, quantifying differences between ice types is important as the sea ice cover shifts from older, thicker ice to younger, thinner ice. We seek to increase knowledge of sea ice behavior at scales relevant to the Arctic system through conducting studies on the thermal strain coefficient.

We conducted in situ studies and used remote sensing techniques to evaluate the thermal-strain relationship of first year, multiyear, and freshwater ice at geophysical scales. The results are presented in the context of existing theories and contradicting laboratory findings. Where available theories are unable to explain observed behavior, new processes are discussed, some present only at geophysical scales. The implications of differing behavior between ice types are evaluated as they contribute to trends in the changing Arctic.

Measuring the rapidly changing conditions and behavior in the Arctic require concerted, interdisciplinary efforts which take full advantage of available tools. As the field expands there are an increasing number of in situ observations, studies on model parameterization, and algorithms for interpreting remote sensing data. A wealth of knowledge, data, and motivation is accumulating in the field. Specifically, there are increased efforts in the past decade to use consecutive synthetic aperture radar (SAR) imagery to estimate large scale drift while simultaneously measuring relative motion between ice floes. Challenge problems are standardized approaches to common topics with a means for direct comparison between different proposed solutions. We have developed challenge problems related to sea ice drift with accessible data sets and well outlined procedures. Data sets take advantage of the available satellite coverage of the Arctic and in situ data. Procedures, recommended approach, and expected output, provide easier comparison between different algorithms.

Thesis Committee

• Christopher Polashenski (Chair)
• Donald Perovich
• Benoit Cushman-Roisin
• Andy Mahoney (University of Alaska, Fairbanks)

Contact

For more information, contact Thayer Registrar at thayer.registrar@dartmouth.edu.