Navigating Great Lakes Hydroclimate Data

Abstract

Despite the fact that the Great Lakes contain roughly 20% of the world's surface freshwater, there is a relatively limited body of recent work in peer reviewed literature that addresses recent trends in lake levels. This work is largely coming from a handful of authors who are most well-versed in the complexities of monitoring and modeling in a basin that spans an international border and contains vast areas of surface water connected by both natural and managed connecting channel flows. At the same time, the recent dramatic changes from record low water levels in the early 2010's to record high water levels across the Great Lakes in 2019 and 2020 have brought significant attention to the hydroclimatic conditions in the basin, underscoring the need to bring new approaches and diverse perspectives (including from outside the basin) to address hydroclimate research challenges in the Great Lakes. Significant effort has led to advancements in data and model coordination among U.S. and Canadian federal agencies throughout the decades, and at the same time research from the broader community has led to higher resolution gridded data products. In this paper, we aim to present the current state of data and models for use in hydrological simulation with the objective of providing a guide to navigating the waters of Great Lakes hydroclimate data. We focus on data for use in modeling water levels, but we expect the information to be more broadly applicable to other hydroclimate research. We approach this by including perspectives from both the Great Lakes water management community and the broader earth science community.

Recent changes in Great Lake hydrologic variability: an artifact of chance or a robust change?

“…To characterize changes in lake level variability, we analyzed lake level data compiled by the Great Lakes Coordinating Committee (Coordinating Committee on Great Lakes Basic Hydraulic Hydrologic Data, n.d.). Monthly mean lake level data are calculated by combining observations from a suite of gauges around the Great Lakes basin maintained by the U.S. National Oceanic and Atmospheric Administration (NOAA) and Canadian Hydrographic Service (CHS) (Fry et al, 2022). These data span from 1918 to the present.…”

“…Overlake evaporation is computed by the Large Lake Thermodynamics Model (LLTM) as described in Croley (1989), and is available from 1950 to present. The LLTM is a 1-dimensional thermodynamics model that computes overlake evaporation by simulating the energy balance above the lake surface, vertically-summed heat storage through the lake columns, and aerodynamic evaporation (Fry et al, 2022). GLM-HMD estimates of runoff are calculated from streamflow measurements from the United States Geological Survey and Water Survey of Canada gauges based on subbasin area with extrapolations for unrepresented subbasin area and ungauged subbasins (Hunter et al, 2015).…”

Research on water level prediction for great lakes based on GAMLSS-GLO model

“…With the increasing impact of global climate change on the hydrological cycle, more and more research is focusing on assessing water level changes under future climate change scenarios. By combining the output of climate models with hydrological models, researchers can predict the long-term effects of climate change on water levels in specific watersheds or lakes [7] . Traditional water level predictions rely heavily on empirical and physically based hydrological models that predict water level changes in rivers and lakes by simulating rainfall-runoff processes in watersheds.…”