Date of Award

Winter 12-18-2019

Level of Access Assigned by Author

Open-Access Thesis

Degree Name

Doctor of Philosophy (PhD)

Department

Civil Engineering

Advisor

Shaleen Jain

Second Committee Member

Aria Amirbahman

Third Committee Member

Jean MacRae

Additional Committee Members

Ramesh Gupta

Firooza Pavri

Abstract

In the northern hemisphere, winter climate conditions are showing dramatic year-to-year swings. To date, implications of a changing winter climate pattern on individual or regional lakes are poorly understood, particularly in cold regions where seasonal ice appears on lake surfaces. This dissertation investigates the significance of yearly winter climate condition on the health and function of freezing lakes by modeling and characterizing the response of lake ice phenology (and related socio-ecological systems) to winter weather-climate variability. In Chapter 2, several case studies on winter limnology are reviewed to develop a tentative socio-ecological framework that demonstrates the local and regional implications of the changing nature of lake ice, and the extent to which the resulting impacts span human and environmental systems. The performances of ice-out date models that incorporate winter degree-days as covariates in Chapter 3 imply that winter temperatures (as degree-days) govern the variability of lake ice-out dates across the three climatic regions in Maine. In Chapter 4, the influence of antecedent winter degree-days on spring ice-out dates is described by determining the winter degree-day thresholds that engender early/late spring ice-out dates. In Chapter 5, quantile regression models were developed to characterize the heterogeneous effect of diverse El Niño-Southern Oscillation (ENSO) events on North American wintertime air temperatures at specific quantiles as well as the entire distribution. Chapter 6 extends the work in Chapter 5 and describes the potential asymmetry in the nature of ENSO related ice-out date anomalies for North American lakes both locally and regionally. In conclusion, the findings here imply that characterizing the relationship between winter climate patterns and lake ice season in cold regions offers forecast of lake structure and function at a seasonal or longer time scale across multiple spatial scales.

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