Breakdown of a Nocturnal Inversion Measured with a Low-Cost Tethersonde System

For the past 4 years, four different cohorts of students from the Science and Technology program at Eleanor Roosevelt High School in Greenbelt, Maryland, have performed their senior research projects at the Howard University Beltsville Research Campus in Beltsville, Maryland. The projects have focused generally on the testing and correction of low-cost sensors and development of instrumentation for use in profiling the lower atmosphere. Specifically, we have developed a low-cost tethersonde system and used it to carry aloft a low-cost instrument that measures particulate matter (PM) as well as a standard radiosonde measuring temperature, pressure, and relative humidity. The low-cost PM sensor was found to provide artificially high values of PM under conditions of elevated relative humidity, likely due to the presence of hygroscopic aerosols. Reference measurements of PM were used to develop a correction technique for the low-cost PM sensor. Profiling measurements of temperature and PM during the breakdown of a nocturnal inversion were performed using the tethersonde system on 30 August 2019. The evolu-tion of temperature during the breakdown of the inversion was studied and compared with model forecasts. The attempt to measure PM during the tethersonde experiment was not successful, we believe, due to the packaging of the low-cost sensor. Future cohorts of students from Eleanor Roosevelt High School students will work on improving the instrumentation and measurements shown here as we continue the collaboration between the Howard University Beltsville Campus and the local school system.

Automated summary

For the past 4 years, students from Eleanor Roosevelt High School in Greenbelt, Maryland, have conducted their senior research projects at the Howard University Beltsville Research Campus in Beltsville, Maryland. Their projects have focused on testing and correcting low-cost sensors and developing instrumentation for profiling the lower atmosphere. The results showed that a correction technique was needed for the low-cost particulate matter (PM) sensor due to inaccuracies caused by hygroscopic aerosols in high humidity conditions. The attempt to measure PM during a recent experiment was unsuccessful.