Laurentian Great Lakes Dynamics, Climate, and Response to Change

Abstract

The Laurentian Great Lakes are one of North America’s greatest water resources. Due to recent record high lake levels and to climate change issues, there is renewed interest in lake level trends and in factors affecting high water levels. Impacts on Great Lakes water supply components and basin storages of water and heat must be understood before lake level impacts can be assessed. The Great Lakes Environmental Research Laboratory (GLERL) developed conceptual simulation models for Great Lakes hydrology to address the impact questions. GLERL integrated the models to estimate lake levels, whole-lake heat storage, whole basin moisture storage, and water and energy balances for forecasts and for assessment of impacts associated with climate change. Because the Great Lakes possess tremendous water and heat storage capacities, they respond slowly to changed meteorologic inputs. This “memory” results in a filtering or dampening of most short-term meteorologic fluctuations and in a response to longer-period fluctuations characteristic of climate change. The large Great Lakes system, thus, is ideal for studying regional effects of climate changes.