University of Illinois researchers discovered significant atmospheric changes during last month's solar eclipse.
And Illinois State Water Survey team documented weather during the eclipse at the Dixon Springs Agricultural Center in Simpson.
Observations by the water survey's Water and Atmospheric Resources Monitoring program found that air temperature fell by about 5 degrees Fahrenheit during the eclipse. Air temperature would typically rise at that time of day.
And solar radiation fell to zero during the eclipse totality. It took more than an hour for recovery of radiation.
Wind speed in Simpson slowed to less than 2 mph. The minimum speed occurred shortly after totality.
Vertical air movements which often occur on sunny summer days produce cumulus clouds and sometimes thunderstorms. The movements ceased during totality and the clouds disappeared.
