Air Quality

Air quality impacts all of us. A clean, safe air supply is a vital societal need and is mandated by the Clean Air Act and its amendments. To meet this requirement the Environmental Protection Agency (EPA) needs access to accurate and timely information on air quality. It is important for the EPA to know what the current state of the air is on a global, regional, and local scale. The agency needs to understand how changes that occur on a global scale impact regional air quality and vice versa, and assess how these conditions are likely to change with time.

NASA plays an important role in these studies. Researchers have developed sophisticated models of the chemistry and dynamics of Earth's atmosphere and are working with the EPA to examine how NASA models might be used to help the EPA better fulfill its air quality management responsibilities. The EPA operates a decision support system used to make air quality forecasts. This decision tool requires input on the atmospheric conditions, which is provided by NASA's atmospheric chemistry and dynamics models.

NASA-funded scientists at the National Center for Atmospheric Research (NCAR) have recently put together an analysis of four years of CO measurements from the MOPITT sensor (Measurements of Pollution in the Troposphere) on NASA's Terra satellite. Learn more about Seasonal Carbon Monoxide Measurements from MOPITT.

NASA's models require input, which is provided from a number of current satellite missions that collect data directly relevant to air quality studies. For example, the Total Ozone Mapping Spectrometer (TOMS) flying on the Earth Probe satellite is another in a series of TOMS instruments that have been collecting valuable information of relevance to studies of ozone mapping and transport, sulfur dioxide emissions, and particulate matter--also known as aerosols--for the past several decades. More recently, a number of instruments on the Terra spacecraft have made significant contributions to air quality studies. Canada's Measurements Of Pollution In The Troposphere (MOPITT) instrument yields global distributions of carbon monoxide. Additionally, the Moderate Resolution Imaging Spectroradiometer (MODIS) is used for studies of various pollutants and the Multiangle Imaging Spectro Radiometer (MISR) is used to study particulate matter (aerosols). The Aqua mission also conducts aerosol studies using its own MODIS sensor, as well as studies of carbon monoxide (CO) and methane (CH4) using the Atmospheric Infrared Sounder (AIRS).

Image: Aerosols affect climate both directly by reflecting and absorbing sunlight and indirectly by modifying clouds. The TOMS aerosol index is an indicator of smoke and dust absorption. The image shows aerosols crossing the Atlantic and Pacific oceans. Dust from the Sahara desert is carried westward toward the Americas. Asian dust and pollution travel to the Pacific Northwest. Credit: Jay Herman (NASA GSFC)

The Aura mission, launched in 2004, is dedicated to studying the chemistry of our atmosphere. Its entire instrument complement is designed to obtain the most comprehensive picture possible of key atmospheric constituents and how these concentrations change with time. It will offer the most detailed information on profiles and transport of ozone that has ever been obtained, with the ability to track ozone and other pollutants as they are transported around the world. The CloudSAT and Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) missions, launched in 2006, will collect data on 3-dimensional distribution of clouds and aerosols and increase our understanding of how these parameters impact air quality.

Over the next ten years, atmospheric chemistry models will use this increasingly detailed information from these NASA missions, to produce simulations that are increasingly realistic and useful for prediction. This will lead to air quality forecasts with increased accuracy and longer lead times. Within ten years, three-day atmospheric forecasts will be possible, along with routine warnings of air quality events such as unhealthful levels of ground-level ozone.

Missions for Air Quality