Name
Lake Superior Evaporation: Presenting 15 years of eddy covariance data at the Stannard Rock Lighthouse
Description
Robust and accurate measurements of evaporation and energy fluxes on the Laurentian Great Lakes are necessary for water balances, regional climatology, and are critical for water level estimates and informed downstream water management. Despite the societal and scientific importance of this information and large historical changes in lake levels, few long term, full-year, direct measurements of surface energy fluxes on the Great Lakes have been reported due to logistical, cost, and safety related challenges. Here, we present 15 years (2008-2022) of eddy covariance data at Stannard Rock, a historic lighthouse on Lake Superior located 38 km southeast of Manitou Island and 72 km north of Marquette, Michigan. Previous analysis has shown pronounced seasonal patterns in the surface energy balance, with a five-month delay between summertime maximum net radiation and maximum latent and sensible heat fluxes in the winter. The majority of evaporative and sensible heat loss is between October and March, with differences among years attributed to shifts in lake surface conditions (i.e. water temperature, ice cover and duration). Annual evaporative losses typically fall between 450-650 mm. In this presentation, we summarize the long-term trends in surface energy fluxes, seasonal and inter-annual variability, and the sensitivity of evaporation to atmospheric and lake conditions. This dataset, which will be shared with the Ameriflux network, improves our ability to represent the drivers and patterns of surface energy fluxes and provide sound predictions of evaporative regimes in the Great Lakes in a changing climate.