Land-Atmosphere Responses to a Total Solar Eclipse in Three Ecosystems With Contrasting Structure and Physiology

Area of Science:

• Atmospheric Science
• Ecology
• Meteorology

Background:

• The 2017 total solar eclipse offered a unique opportunity to study land-atmosphere interactions.
• Understanding ecosystem responses to rapid changes in solar irradiance is crucial for climate modeling.

Purpose of the Study:

• To investigate the effects of the 2017 solar eclipse on land-atmosphere exchanges in three distinct ecosystems: forest, prairie, and soybeans.
• To quantify changes in turbulence, energy fluxes, and surface conductance during the eclipse.

Main Methods:

• Field experiments were conducted at forest, prairie, and soybean sites in Mid-Missouri during the 2017 total solar eclipse.
• Measurements included solar irradiance, wind velocity, friction velocity, and eddy fluxes of energy (latent and sensible heat).
• Canopy-scale time constants for surface conductance were estimated for the prairie site.

Main Results:

• Turbulence was suppressed across all sites, with significant decreases in wind and friction velocities.
• Eddy fluxes of latent and sensible heat were highly coherent with solar forcing, approaching 0 W/m² and changing direction.
• The prairie site exhibited a canopy-scale time constant for surface conductance light response of 10 minutes.
• Air temperature decreased by 1.5-2.5 °C, a muted response attributed to moist conditions and lack of topographic effects.

Conclusions:

• Solar eclipses significantly impact land-atmosphere energy exchange dynamics across different ecosystems.
• Ecosystem type influences the magnitude of turbulence suppression and energy flux responses.
• The study provides valuable data for validating land surface models under extreme radiative forcing events.