Spotlight: Monitoring Carbon Dioxide Measurements During a Solar Eclipse

Depending on where you were during the solar eclipse, you may have been able to witness something that only happens every so often. At our Gaithersburg, Maryland, campus, a few NIST researchers watched the solar event with science on their minds.

During the day, plants undergo photosynthesis, during which they absorb sunlight and carbon dioxide, or CO₂, to create food and energy, lowering CO₂ concentrations in the local atmosphere. Researchers were curious as to whether their sensors would detect any changes to the concentration of CO₂ during an eclipse.

To investigate, they used two different types of sensors.

Their low-cost sensor platform (shown here) is made up of three commercially available sensors — originally used to measure indoor air quality — and a single-board computer, which serves as the brains of the device. The platform works alongside reference gases with known concentrations and compares its CO₂ measurements against them.

The second type of sensor can detect CO₂ measurements with a very high precision of 0.1 parts per million.

Did they notice a difference in CO₂ levels? The simple answer is yes. Researchers ran a brief analysis and found that exactly on the dot at 3:20 PM, which was the height of the solar eclipse in Gaithersburg, the CO₂ concentrations spiked a little bit. All three low-cost sensors and the high-cost sensor were able to detect the small change.

As for what this means, further analysis is needed — so stay tuned for results!