Impacts of Lake Surface Temperature on the Summer Climate Over the Great Lakes Region

Abstract

The total surface area of the Great Lakes is over 94,250 miles 2 . Consisting of five large lakes, they contain over one fifth of the world's total surface fresh water, with depths of up to 400 m (EPA, 2020). The Great Lakes substantially influence the regional weather and climate via their effects on the atmospheric energy and water budget; open water typically has greater thermal conductance, lower albedo, and lower roughness compared to soil or vegetated surfaces (Notaro et al.,2013;Scott & Huff, 1996). The large thermal inertia of the lakes leads to a reduction in annual and diurnal temperature ranges across the Great Lakes Basin (Harris & Kotamarthi, 2005;Notaro et al., 2013). Mean minimum temperatures in the region are warmer during all seasons and over all five lakes, while maximum temperatures are cooler during spring and summer (Scott & Huff, 1996). Lake thermal impacts and associated evaporation have a strong influence on regional precipitation patterns. While many studies have investigated the impact of lake surface temperature (LST) on the cold-season precipitationwhich is primarily a direct product of warmth and moisture from the Great Lakes (e.g., lake-effect snow; Notaro et al., 2021; Shi & Xue, 2019)-the impact of LST on summer precipitation has only rarely been studied. During early summer, the lake surface is still relatively cool compared to the atmosphere, resulting in condensation on the lake surface and a stable boundary layer that deters over-lake convective processes (Miner & Fritsch, 1997;Workoff et al., 2012). Due to the temperature differences over lake and inland, lake breeze can cause air to rise inland and increases the likelihood of over-land precipitation (Schulkowski, 2020). During late summer, while the land cools and the lakes remain warm, the temperature differential between land and lake surface coupled with baroclinic waves (e.g., cold front and trough) and/or the Great Plains low-level jets can generate enhanced precipitation (Feng et al., 2016;Miner & Fritsch, 1997). Therefore, changes in summer LST could potentially affect its feedback to atmospheric stability and change the water and energy budget over the entire Great Lakes Region (GLR). The summer is an ideal time to evaluate the influence of LST on the lake surface-atmosphere

Urban versus lake impacts on heat stress and its disparities in a shoreline city

“…Moreover, street-level urban vegetation is not explicitly represented, which can modulate wind speed, air temperature, and relative humidity 44 . Similarly, there are simpli cations in lake representation in WRF that can impact summertime temperatures, particularly along the land-water interface 27 , where we found the uncertainty due to model internal variability to be largest. On the evaluation side, WRF-simulated skin temperature is integrated over an idealized 3D urban canyon, while satellites provide a 2D directional view of a 3D heterogeneous urban landscape 64 .…”

“…Overall, it is evident that Lake Michigan has a stronger impact on heat exposure and heat stress in the region during daytime, while urbanization has a stronger impact at night. For almost all variables, the standard errors across the ve ensemble simulations are greatest closest to the shore (Figs 3 and S4), demonstrating the high sensitivity of the micro-climate at the land-water interface simulated by the model to initial conditions 27 .…”

“…We use Weather Research and Forecasting (WRF; version 4.3.1) model simulations 50 centered at 45.5°N and 85.0°W and covering the Great Lakes region with a grid spacing of 4 km and 50 stretched vertical levels starting from 30.2 m above the ground 27 to simulate summertime conditions over Chicago. The initial and boundary conditions for the model (at 0.25 degree resolution every 3 hours) are taken from the European Centre for Medium-Range Weather Forecasts atmospheric reanalysis of the global climate, version 5 (ERA5) 51 , while the boundary condition for the lake surface temperature (daily at 1.3 km) is from satellite-derived estimates from the National Oceanic and Atmospheric Administration (NOAA) Great Lakes Surface Environmental Analysis 52 .…”

Moisture Sources of Precipitation in the Great Lakes Region: Climatology and Recent Changes

“…Locally, by supplying heat and moisture, the Great Lakes facilitate the formation of lake‐effect snowstorms in winter and convective storms in summer (Notaro et al., 2015; Shi & Xue, 2019). Regionally, the lakes can modify atmospheric circulation and other mesoscale features, affecting precipitation and water cycle outside the GLR in nearby regions (Bryan et al., 2015; Notaro et al., 2013; Petterssen & Calabrese, 1959; Sousounis & Fritsch, 1994; Wang et al., 2022).…”

Lake Surface Temperature Dataset in the North Slave Region Retrieved from Landsat Satellite Series – 1984 to 2021

“…variable in regional studies, the impact and relationship of LST to weather, climate and lake processes have been explored by other studies including influences on weather (Kheyrollah Pour et al, 2014a,b;Eerola et al, 2014;Kheyrollah Pour et al, 2017), climate (Moigne et al, 2016;Wang et al, 2021), precipitation (Zhang et al, 2016), lake effect snow (Shi & Xie, 2019) and lake overturning (Fichot et al, 2019). Observations of lakes around the world have reported increases in lake temperature associated with global warming resulting in changes to the underlying lake system (O'Reilly et al, 2015;Woolway et al, 2019).…”