Impacts of Lake Surface Temperature on the Summer Climate Over the Great Lakes Region
Small variations in lake surface temperature can significantly influence atmospheric conditions, raising air temperatures, enhancing evaporation, and altering precipitation patterns in the Great Lakes Region.
The Great Lakes, taken June 23, 2022 during Expedition 67 of the International Space Station by NASA, in the public domain.
The Great Lakes cover more than 94,250 square miles and hold over one-fifth of the world's fresh surface water. Their vast size affects weather and climate by influencing atmospheric energy and water distribution. However, many climate models fail to fully capture how the lakes interact with the atmosphere, which can skew predictions for the Great Lakes Region (GLR). This study examines how the temperature of the lake surfaces during summer affects regional climate conditions, such as air temperature and rainfall, over the GLR.
Our research shows that using different data sets for lake surface temperatures (LST) in climate models impacts not only local weather but also weather far from the lakes. Inaccurate LST data can result in incorrect predictions for air temperature and rainfall over the lakes and nearby lands. This affects both short-term and long-term weather forecasts, including predictions of lake levels and storm formation near the lakes. It is essential to use realistic models that fully account for interactions between the lakes and the atmosphere to accurately represent the region's climate.
Our study found significant differences in air temperatures over Lake Superior and Lake Erie when using an average lake surface temperature difference of 1.4°C. These temperature variations (1.93°C for Lake Superior and 0.97°C for Lake Erie) influence the latent heat released from the lakes and the moisture available for rain formation. The effects of these warmer temperatures also extend beyond the Great Lakes, causing decreases in rainfall in the western parts of the GLR and increases in heavy, short-term rainfall in the eastern parts.