Home | NASA Air Quality Applied Sciences Team (AQAST)

Since 2013, members of the NASA Air Quality Applied Sciences Team (AQAST) have been working with state and federal air agencies across the Eastern U.S. The "tiger team" led by Dr. Tracey Holloway and Dr. Arlene Fiore has developed this website to summarize recent research in a format designed to support decision-makers and analysts. We also include links and resources for many of the other high-value AQAST activities over the 2011-2016 AQAST period.

Overview of satellite data for U.S. air quality

6-16-16 DRAFT ONLY do not cite or quote

Satellite data support the qualitative and quantitative analysis of air pollution and impacts on a local, national and global scale. Here we provide two overview articles on the relevance of satellite data for policy applications:

Opportunities and challenges in using satellite data for U.S. air quality management (AQAST perspective), and

The value of satellite data for ozone and particulate matter source attribution (EPA perspective).

Using satellite and other earth-science data in the SIP process

Evaluating air quality trends and patterns

6-30-16 DRAFT ONLY do not cite or quote

Satellite data provides powerful visualizations and metrics on air pollution, showing temporal and spatial patterns in air pollution, especially for NO_x (via NO₂), VOCs (via HCHO), and particulate matter (via AOD). These data can support public outreach, trends reports, emission inventory development, and other applications. Read more

Quantifying dust and smoke transport

Model evaluation

Source-apportionment methods

6-30-16 DRAFT ONLY do not cite or quote

Where does air pollution come from? And where does it go? Here we describe the different ways in which air quality models can be used to track down the contribution of pollution from different sources (such as transportation versus power plants, or foreign versus domestic sources) as well as the pros and cons of different methods for addressing different types of air quality management questions. Knowledge of contributions from individual sources is needed to implement effective pollution control programs. Read more

Quantifying background ozone

6-16-16 DRAFT ONLY do not cite or quote

Developing effective air pollution control policies requires knowledge of the portion of air pollution due to sources other than U.S. anthropogenic emissions (natural sources or foreign pollution). High “background” events may be screened out from counting toward attainment determinations if they qualify as "exceptional events." In other cases, consideration of background ozone can lead to less stringent control requirements for areas designated as non-attainment. Read more

Application of satellite data for short-term analysis

6-30-16 DRAFT ONLY do not cite or quote

A region’s attainment of the National Ambient Air Quality Standards (NAAQS) is often determined by the number and magnitude of peak air pollution events. However, these events can be difficult to diagnose with ground-based data alone, especially in regions with sparsely located monitors. Satellite data can provide information on spatial patterns and/or vertical pollution distribution to support the diagnosis of peak events. Read more

Chemical production of ozone

6-30-16 DRAFT ONLY do not cite or quote

Total column retrievals of formaldehyde (HCHO) and tropospheric NO₂ columns can provide insight into the sensitivity of ozone formation to emissions of NO_x versus VOC. In general, eastern U.S. regional ozone is sensitive to NO_x emissions during the warm season due to abundantly available biogenic hydrocarbon (isoprene) emitted from vegetation. In some urban areas, however, ozone chemistry is dominated by anthropogenic VOCs and will respond to reductions in these anthropogenic VOCs. As demonstrated over the past decades, NO_x reductions are necessary to reduce ozone across the eastern U.S. region. Knowledge of NO_x-versus-VOC sensitivity is thus most useful for guiding local (urban) air management strategies. Policy-makers with limited resources seeking to optimize the number of people protected from excess ozone may use this information to decide when and where to control VOCs as well as NO_x. Read more

Landsat 8 satellite imagery (false color) of a destructive wildfire in Canada’s northern Alberta region on 3 May 2016. Credit: NASA's Earth Observatory.