PhD Thesis Proposal: Cameron J. Planck

Tuesday, January 14, 2020, 1:00–3:00pm

Rm 101, MacLean ESC

"Methods for Assessing Changes to Sea Ice Mass Balance in The Arctic Ocean"

Abstract

Arctic sea ice plays a crucial role in the global climate system, acting as both an indicator and an amplifier of climate change. Sea ice mass balance, which is simply the net difference between ice grown and ice melted, is an important parameter that can connect changes in ice thickness to environmental forcings. While powerful as a concept, observations of sea ice mass balance remain limited. This is due, in part, to the difficulty of sustaining observational campaigns in the harsh, Arctic, environment. The ability to determine sea ice mass balance thus represents a significant limitation in the understanding of how the sea ice cover has evolved in the past and how it will continue to evolve in the future. In this work, we seek to increase knowledge of past, present, and future sea ice mass balance through two methods: first, by developing an improved system for gathering mass balance observations; and second, through detailed time series analysis of mass balance observations in a region of the Arctic which has experienced substantial change, the Beaufort Sea.  The first part of this thesis presents an autonomous sea ice mass balance monitoring system that was created with features that maximize reliability and survivability, reduce installation difficultly, and reduce cost. The design methods, considerations, stakeholders, and final product are discussed, and results from a prototype deployment and a live observational campaign are also presented. In the second part of this work, results from eight Beaufort Sea mass balance sites spanning three decades are examined in detail. Time series of mass balance variables such as ice growth, melt, and snow accumulation are compared to estimates of environmental heat fluxes. At all sites, a net loss of ice was observed. At 21st century sites, bottom melt was the leading mode of ice loss, and was correlated to the solar heat deposited into the upper ocean. The final component of this work proposes to extend the results from the eight Beaufort sites to examine the driving force of ice growth in winter: the surface conductive flux. Comparisons between the observationally determined conductive flux and results from reanalysis will be made with the goal of identifying trends and traits across sites and years.

Thesis Committee

For more information, contact Daryl Laware at daryl.a.laware@dartmouth.edu.