As the total solar eclipse darkened our skies on April 8, the Indiana Geological and Water Survey had citizen scientists across Indiana collect data that will ultimately help geologists better understand light energy and solar radiation and their effect on the water cycle.
"Solar energy powers the whole water cycle, with how water moves from evaporation to condensation and precipitation," said Ginger Davis, the lead geoscientist on the project. "The amount of energy determines how much water is removed, and knowing that information tells us how much water is removed from the soil to the atmosphere. It's the idea of, are we having a massive amount of evaporation or having a minor amount of evaporation? And that really does influence how we look at droughts and movement of water during droughts."
The Indiana Geological and Water Survey received more than 752 data submissions from March 21 to April 10, with about a third of them coming on the day of the eclipse. The citizen scientists used a free "lux meter" app on their phones to measure the amount of light in the sky.
Submissions came from 17 Indiana counties as well as five other states, with one avid weather watcher from Greenwood providing 55 percent of the submissions. While researchers with the Indiana Geological and Water Survey will only use data from Indiana to build a data set for this particular project, they were surprised by the far-reaching interest and quality of the data received.
"We have some very science-oriented citizens in our community who are very willing and able to help out when they can," Davis said.
The Indiana Geological and Water Survey chose to crowdsource data for this project to fill in gaps in its network of climate stations and to test whether lux readings, or the amount of light, are a good proxy for solar radiation. Solar radiation is measured by sensors at all 15 Indiana Water Balance Network stations - a statewide network of Indiana Geological and Water Survey monitoring stations that collect various types of hydrologic data, such as soil moisture and groundwater levels, to monitor long-term trends in the water cycle. But because each station only captures data from its specific area, the information collected isn't representative of the entire state. The solar eclipse, a time when millions of Hoosiers and other visitors would be looking at the sky, seemed like a natural opportunity to gather widespread data about light, or the lack of it.
Indiana Geological and Water Survey geoscientists will compare data collected at the Indiana Water Balance Network stations with the data that citizen scientists collected on their phones. If data from free lux meter apps proves comparable to sensor data, that could provide opportunities to capture more readings regularly on a wider scale.
"The big end goal is whether light can be used as a proxy for solar radiation," Davis said. "There's been some research into this in the past, but past research has been done with nationwide data sets in the solar industry. We're bringing it home to Indiana."
The greatest concentration of citizen science data came from the Indianapolis, Bloomington, and Gary areas, where the Indiana Geological and Water Survey has six Indiana Water Balance Network stations. Data comparison research will be focused in these areas.
The Indiana Geological and Water Survey will also use this data to create a lesson plan that Hoosier teachers can use to educate the next generation of engineers and earth scientists about lux and solar radiation. The data could be interesting to the solar power industry as well.
This was one of the Indiana Geological and Water Survey's first times asking the public to contribute to research. Davis said she was thrilled with the results.
"With the great success that we had, I can imagine putting more time into the call-out (for participation), and we will have much greater success, which allows us to think about how we might do more things in the future," she said.
