Investigating Trends in Urban Nitrogen Dioxide Pollution Across the US

Project Partner: NASA Langley Research Center, Summer 2025

Project Summary: Rachel’s internship was with the Integrating Multiple Perspectives of Air Quality Team (IMPAQT) at NASA Langley, using data from the newly-launched TEMPO satellite to understand how pollution is changing in U.S. cities. Studying how pollution evolves throughout the country is challenging because data is sparse: there are few surface monitors, and previous satellites only collected a single measurement each day. The TEMPO satellite now provides hourly measurements of pollutants across North America. Rachel’s work with NASA focused on nitrogen dioxide (NO₂), which is harmful to human health and reacts in the atmosphere to form other harmful chemicals including ozone. With hourly data, she was able to determine how levels of pollution change over the course of an average day in dozens of cities. Furthermore, her work included ground-based measurements to help confirm whether or not TEMPO is performing well at monitoring pollution in each of these locations. The results can be applied to inform targeted emissions reductions and to reduce the exposure of vulnerable populations to air pollution. Rachel wrapped up the internship by presenting a poster synthesizing her results at the 2025 TEMPO Science Team Meeting in Cambridge, MA, and by writing a policy brief translating her findings into recommendations for cities.

Project Deliverables:

• Distilled large air quality datasets from the TEMPO satellite and surface observations into key statistics and trends for ~50 U.S. cities
• Presented a poster highlighting key results of urban air quality and how the TEMPO satellite compares to measurements taken from the ground
• Identified cities for the HAMAQ air quality flight campaign (scheduled for summer 2027), which will advance our scientific understanding of NO₂ variability

Watch Rachel’s URBAN Internship Lightning Talk here.