Nitrogen dioxide (NO 2 ) is unhealthy to breathe and is a necessary ingredient for the formation of unhealthy levels of surface ozone [NASA Air Quality]. NASA Aura's OMI sensor has been monitoring NO 2 data since 2004 and has been used in a variety of health and air quality applications. The TROPOMI instrument onboard Sentinel-5P, launched in 2017, represents a significant improvement in spatial resolution over OMI. It will be better-suited for many applications currently using OMI data, including monitoring air pollution. In this advanced webinar, attendees will learn how to access and analyze TROPOMI data, and learn about its applications.