Solar Eclipse Radiosonde Launch Project

On August 21, 2017, the United States experienced a total solar eclipse from coast to coast for the first time in 38 years. This event provided a unique opportunity to study the vertical profile of the atmosphere during the duration of a solar eclipse through the deployment of instrumented balloons capable of measuring temperature, wind speed and direction, and humidity. Six students and three faculty members from Valparaiso University worked in cooperation with the University of Montana in an effort to coordinate radiosonde launches across the path of totality in North America. Four launches were conducted in Coulterville, Illinois measuring the state of the atmosphere before, during, and after the event. Goals of this project centered on the eclipse’s impact on temperature, barometric pressure, humidity, and wind variations from the surface to the middle of the troposphere. Key discoveries include a decrease in both surface temperature and dew point coincident with an increase in wind speed, particularly during and after eclipse totality. Temperature was measured in ten minute intervals with an eclipse-driven minimum temperature observed two minutes after totality. Winds near the surface continually increased between the first and third launches while a slight decrease was measured after the fourth launch. It is hypothesized the fluctuations in wind speed are a consequence of temperature changes within the boundary layer.