Increasing Western Wildfires Will Affect Air Quality at NASA Centers

Smoke emissions from wildfires and other types of biomass burning are a significant source of trace gases and particles. NASA Centers in the western US have seen decreasing air quality since the mid-2010’s as the size and frequency of large wildfires have increased. The NASA Climate Adaptation Science Investigators (CASI2) Fires and Air Quality Working Group used historical MERRA-2 data for NASA Ames Research Center in the San Francisco Bay Area and the Jet Propulsion Laboratory (JPL) near Los Angeles to develop a model to estimate potential fire-generated surface particulate matter (PM, approximated as the sum of black carbon and organic carbon).

To generate scenarios of future annual average fire-generated PM, we applied our model to projections of future climate variables, including temperature (maximum, minimum, and mean), relative humidity, precipitation, and wind speed. These variables were taken from the NASA Earth Exchange Global Daily Downscaled Projections (NEX-GDDP) dataset to assess three emissions scenarios, known as Shared Socio-economic Pathways, or SSPs.

We will present projections of fire-generated PM for low (SSP1-2.6), intermediate (SSP2-4.5), and high (SSP3-7.0) scenarios for both NASA Ames and JPL. Our findings show that by the middle of the 21st century, on two of the three trajectories studied, the annual average fire-generated PM is expected to exceed that of 2020, the year in which California experienced multiple lightning strike fire complexes across the state. If the high emission scenario represents near-term global climate conditions, both NASA Centers will routinely exceed their 2020 fire-generated PM averages by the year 2035. For the intermediate scenario studied, NASA Ames reaches this threshold ~2043, while JPL reaches this threshold a few years sooner.

This steadily-increasing annual average of fire-generated PM will become the baseline on top of which the interannual variability of short-term smoke events will be compounded, impacting the conditions experienced by NASA personnel and facilities. Because the majority of work at both Ames and JPL is accomplished in a variety of office spaces, we will compare historical observations of outdoor and indoor air quality data collected in multiple buildings at NASA Ames. The CASI-2 partnership between Science and Infrastructure organizations at NASA has facilitated this combination of local knowledge and observational data with climate projections to serve the NASA Centers’ needs for resilience planning, as well as near term decision-making regarding HVAC needs for individual buildings.