Student Research - Mission Earth

Atmospheric aerosols are suspended particles that scatter and absorb sunlight, influencing climate, reducing air quality, and contributing to respiratory and cardiovascular disease. Aerosol Optical Depth (AOD) is widely used to quantify atmospheric aerosol loading and monitor changes in aerosol concentrations. This study evaluated whether a low-cost, student-built GLOBE Sun Photometer could reliably measure AOD by comparison with a commercial Calitoo Sun Photometer. Measurements were collected in Dearborn Heights, Michigan, over a six-day period from July 14-19, 2026, at 15-minute intervals around solar noon following NASA GLOBE protocols. Across all sampling days, the homemade photometer consistently captured the same temporal changes in AOD as the commercial instrument, although it generally reported slightly higher absolute values. During the study, smoke from Canadian wildfires increased aerosol concentrations over southeast Michigan, preventing measurements on July 16 and providing an opportunity to evaluate instrument performance under elevated aerosol conditions when observations resumed. Both photometers detected the increase in AOD associated with the smoke plume, demonstrating similar responses to changing atmospheric aerosol loading. These findings suggest that the homemade GLOBE Sun Photometer is a practical, low-cost tool for monitoring atmospheric aerosols and supporting atmospheric research, STEM education, and citizen science.