Publicly available NASA satellite data can help with State Implementation Plans (SIPs)
NASA’s Earth science program maintains a large fleet of earth-observing satellites, all of which offer free data products. A number of these can be used to illustrate NOx emissions trends and their relevance to ozone attainment, as well as for weight-of-evidence under the EPA’s Exceptional Events Rule. A collaborative team of NASA-funded scientists and public stakeholders has recently developed a suite of easy-to-follow technical guidance documents to support state and local air quality agencies that want to bring the power of NASA’s satellites to bear on the documentation of exceptional events. This work is a product of the NASA Health and Air Quality Applied Sciences Team (HAQAST) Year 1 (2017-2018) Tiger Team “Supporting the Use of Satellite Data in State Implementation Plans (SIPs)”
What, specifically, can NASA help me with? Our team has developed three guidance documents:
The change in the sensitivity of O3 formation from 2005 to 2015 as inferred from Aura OMI HCHO and NO2 data. This figure is based on the work of Jin et al. (2017). Figure credit: NASA.
Using satellite observed formaldehyde (HCHO) and nitrogen dioxide (NO2) as an indicator of ozone sensitivity in a SIP: Although State Implementation Plans (SIPs) typically rely on observations from ground-based networks and regulatory models, satellite data is increasingly available to state agencies and can also inform and supplement state implementation plans to improve air quality. An advantage of satellite data is that it provides information for a broader area than sampled by ground-based networks. This document provides examples and guidance for using satellite products of formaldehyde (HCHO) and nitrogen dioxide (NO2) to inform ground-level ozone sensitivity to emissions of nitrogen oxides (NOx) versus volatile organic compounds (VOC) in state implementation plans. Analysis of changes in ozone sensitivity over periods where emission controls have been implemented can provide insights into the efficacy of those past strategies and the likely efficacy of proposed future emission control programs.
True color image of the widespread impact of the Fort McMurray wildfires in May 2016 on air quality in the U.S. Figure credit: NASA.
The Exceptional Events Rule, contained in Title 40 of the Code of Federal Regulations Part 50.14 (40CFR50.14), was revised by EPA in October of 2016. Although many elements go into the technical support document for an exceptional event, this guidance will cover the resources available from satellite images and data to support the weight of evidence. The following guidance played a critical role for the State of Connecticut in its successful demonstration to exclude ozone data from May 25-26, 2016 at several of its monitors because of the transport of pollutants from the wildfires at Fort McMurray, Alberta, Canada.
Have air quality managers used satellite data in submitted SIPs?
Yes. Our technical guidance documents were developed in close concert with air-quality experts at a number of state agencies, including the Texas Commission on Environmental Quality (TCEQ) and Connecticut’s Department of Energy and Environmental Protection (DEEP). Satellite data can be used as one component of your overall weight of evidence (alongside evidence from ground monitors, models, etc.) Our technical guidance documents provide field-tested examples of successful uses.
HAQAST Lead: Dr. Arlene Fiore (firstname.lastname@example.org)
HAQAST Participants: Dr. Bryan Duncan, Dr. Jessica Neu, Dr. Daven Henze, Dr. Talat Odman, Dr. Ted Russell, Dr. Daniel Tong, Dr. Mark Zondlo, Dr. Jonathan Patz, Dr. Tracey Holloway, Dr. Jeremy Hess
Stakeholder Partners: South Coast Air Quality Management District, Mid-Atlantic Regional Air management Association, Northeast States for Coordinated Air Use Management, Georgia Environmental Protection Division, Texas Commission on Environmental Quality, Bay Area Air Quality Management District, US EPA, Connecticut Department of Energy and Environmental Protection.