Our overarching goal is to increase the value of NASA earth science products for monitoring fine particulate matter (PM2.5) near the earth s surface. Satellite aerosol optical depth (AOD) is a measure…

This is a $1,607,640 Cooperative Agreement awarded by NASA to the non-profit Research Triangle Institute (RTI International) to collect and analyze data from low-cost air quality sensors deployed by citizen scientists in three regions (Raleigh, Los Angeles, and Delhi) to improve the ability to estimate fine particulate matter (PM2.5) concentrations from satellite aerosol measurements. The goal is to enhance the value of NASA's Earth science data products for monitoring air quality near the surface. The project builds on a prototype phase that evaluated sensor performance and recruited initial citizen scientists, and will expand the sensor deployment and outreach efforts. All data will be provided through an open-source web portal. There is no set-aside designation for this award.

Our overarching goal is to increase the value of NASA earth science products for monitoring fine particulate matter (PM2.5) near the earth s surface. Satellite aerosol optical depth (AOD) is a measure of the integrated aerosol loading through the entire column of the atmosphere. Surface PM2.5 can be predicted from satellite AOD by incorporating data from fixed ground monitors and additional a priori assumptions. However, satellite-derived surface PM2.5 remains highly uncertain due to limited high-quality point measurements and uncertainties in AOD-PM2.5 relationships for different regions. To address these challenges, we propose to collect spatially dense, quality PM2.5 data using low-cost sensors deployed by citizen scientists in three regions representing low (raleigh, NC), moderate (LOS angeles, CA), and high (delhi, india) PM2.5 loadings. The surface PM2.5 gradients from sensors can be used to validate gradients in satellite-derived PM2.5 and help fine-tune region-specific interpretation of satellite data for PM2.5 monitoring. By leveraging local citizen scientists and open data platform, such efforts can be cost-effective and sustainable, while also enhancing NASA􀁇s mission. During the prototype phase (phase 1), we evaluated 20 commercial low-cost sensors in the lab and field under varying conditions. Of these, the purpleair PA-II sensor met our 10-point criteria for field deployment by citizen scientists in the LOS angeles basin. The data show excellent performance by PA-II sensors, but highlight the need for in-field calibration in the region of interest. To date, 48 citizen scientists (aged 15 to 55+) have been recruited for sensor deployment through outreach with schools and universities and word-of-mouth. Citizen scientists were engaged in a 1-day workshop that included hands-on activities, followed by continual engagement via online blogs, school projects, etc. A website with a preliminary data display system has been developed (aqcitizenscience.RTI.ORG). In the implementation phase (phase 2), we will build on the key lessons learned from phase 1, including (a) the need for region-specific sensor calibration; and (b) difficulty in recruiting citizen scientists for every satellite pixel of interest. We will modify recruitment criteria and intensify outreach to recruit citizen scientists. We will extend citizen science activity and sensor deployment to a total of three regions to better characterize AOD-PM2.5 relationships in a variety of conditions. The widespread global use of purpleair sensors (~1,000) and their existing open data transfer framework (wireless real-time transfer) strengthens project sustainability. Hence, we propose to work closely with the purpleair sensor manufacturer (new collaborator) to expand access to these data, thereby increasing the pool of citizen scientists to contribute to our project framework. All data will continually feed to a flexible open-source web portal for bias-correction, visualization, archive, and analysis. Upon project completion, we propose to involve local regulatory or citizen science groups to continue the program using the established framework for sustainability of the project. By combining data from surface measurements (sensors, fixed monitors, aeronet), satellites (modis AOD at 1-, 3- and 10-KM), and regional air quality model (cmaq), we will examine the AOD-PM2.5 relationship for each region and assess the impact of spatial resolution. The improved scientific understanding from this project will improve the value of air quality datasets from NASA􀁇s current (modis, viirs) and future (tempo, maia) missions, as well as other missions (NOAA􀁇s goes-r; goes-s; korean gems; european sentinal-4).