Location
Online (Email amgrad@uwaterloo.ca) for link
Candidate
Erika Kember | Applied Mathematics, University of Waterloo
Title
Modelling Water Temperature Evolution Under Partial Ice Cover
Abstract
Water’s nonlinear density as a function of temperature is an important factor in the overall state of a lake, and is one that frequently causes vertical mixing from density differences in the water column of freshwater lakes in cold climate zones during spring and fall. Horizontal mixing due to lateral density differences in said lakes is also possible, but is often not considered in lake temperature models. As climate change influences global temperatures and weather patterns, partial ice cover has become more prevalent on northern lakes during the winter. Due to the differing absorptive properties of ice and water, areas of a lake that are covered by ice can experience less radiative heating than areas of open water, causing the adjacent zones of water to have different densities and therefore driving horizontal transport between them. Currently the predominant lake temperature models are not well equipped to handle this type of horizontal transport that occurs under partial ice cover. This thesis presents a "simplest possible" differential equation box model for lake temperature under partial ice cover that incorporates horizontal transport between areas of open water and ice cover. It is evaluated on its ability to give realistic water temperature results. Two regimes are studied: first, a constant insolation framework for analysis of heat transport parameter values, and second is a day cycle framework in which an emissivity switch is implemented to increase physical realism.