February 21, 2019
A 2017 Planetary-Scale Power Outage: Weather and Ecological Impacts of a Total Solar Eclipse
A network of eddy covariance flux towers enabled the detailed study of micrometeorological and ecosystem responses to a total solar eclipse.
Cyclic variations in solar energy at the Earth’s surface is the reason we experience changes in weather and the driver of the natural rhythms of ecosystems. Solar eclipses offer the rare chance to study how the weather and ecosystems respond to an abrupt environmental disruption of known intensity and duration—allowing for an outdoor, controlled-light experiment at the scale of whole ecosystems. This enables novel analyses of ecosystem processes and biosphere-atmosphere interactions. Additionally, rare natural events such as a total solar eclipse capture the attention of the public, providing a starting point for discussions that advance the general science education of the general public.
Knowledge of these ecosystems responses to such an abrupt perturbation of the forces driving energy, water, and carbon through those systems can inform models that scientists use to forecast weather or evaluate probable effects of future climate on ecosystems.
Mid-Missouri experienced up to 2 minutes 40 seconds of totality at around noontime during the total eclipse of 2017. Researchers conducted the Mid-Missouri Eclipse Meteorology Experiment (MMEME) to examine land-atmosphere interactions during the eclipse. Here, research examining the eclipse responses in three contrasting ecosystems (forest, prairie, and soybeans) is described. There was variable cloudiness around at the beginning and end of the eclipse at the forest and prairie; however, skies cleared during the eclipse. Unfortunately, there were thunderstorms at the soybean site, which masked the eclipse effect and exposed the field to cold outflow. Turbulence and wind speeds decreased during the eclipse at all sites, but there was amplified turbulent intensity at the soybean site during the passage of a gust front. Evaporation and heating of the atmosphere by the land surface shut off during the eclipse as air became more stable, with the atmosphere actually supplying some heat to the surface at totality. Although the eclipse had a large effect on surface energy balances, the air temperature response was relatively muted due to the absence of topographic effects and the relatively moist land and atmosphere.
University of Missouri
U.S. Department of Energy, Biological and Environmental Research (SC-33)
Environmental System Science
Support by the Goddard Space Flight Center of the National Aeronautics and Space Administration; Terrestrial Ecosystem Science program of the Office of Biological and Environmental Research within the U.S. Department of Energy Office of Science; U.S. Department of Agriculture Agricultural Research Service; and the National Science Foundation through the Missouri Established Program to Stimulate Competitive Research (EPSCoR).
Wood, J. D, E. J. Sadler, N.I. Fox, S.T. Greer, et al. "Land-atmosphere responses to a total solar eclipse in three ecosystems with contrasting structure and physiology". Journal of Geophysical Research: Atmospheres 124 (2), 530–543 (2018). https://doi.org/10.1029/2018JD029630.