The Mid-Missouri Eclipse Meteorology Experiment (MMEME): Community Engagement in Observing Boundary Layer and Ecosystem Response to a Total Eclipse

Mid-Missouri experienced up to 2 m 40 s of totality at around solar noon during the total eclipse of August 2017. We 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 1^st and 4^th contact at the forest and prairie, however, solar irradiance (K_↓) signals during the eclipse were relatively clean (K_↓ at 1^st and 4^th contact about 750–800 W m^-2). Unfortunately, the eclipse forcing at the soybean field was contaminated by convective activity, which decreased K_↓ beginning about an hour before 1^st contact and exposed the field to cold outflow about 30 min before 2^nd contact. Turbulence was suppressed during the eclipse. The standard deviations of the horizontal and vertical wind velocities, and friction velocities decreased by approximately 75% at the forest (aerodynamically rough), and ~60% at the prairie (aerodynamically smooth). The eddy fluxes of energy were highly coherent with the solar forcing with the latent and sensible heat fluxes approaching 0 W m⁻² and changing in direction, respectively. For the prairie site, we estimated a canopy scale time constant for the surface conductance light response of 10 min. Although the eclipse imparted large forcings on surface energy balances, the air temperature response was relatively muted (1.5–2.5 °C decrease) due to the absence of topographic effects and the relatively moist land and atmosphere (i.e., higher thermal inertia).