Sample Air Quality Forecast Guidance

Overview

The National Oceanic and Atmospheric Administration (NOAA), in partnership with the Environmental Protection Agency (EPA), issues daily air quality forecast guidance as part of a national Air Quality Forecasting Capability. Air quality has improved significantly since the passage of the Clean Air Act in 1970. However, there are still many areas of the country where the public is exposed to unhealthy levels of air pollutants and sensitive ecosystems are damaged by air pollution. Poor air quality is responsible in the U.S. for an estimated 50,000 premature deaths each year; costs from air pollution-related illness are estimated at $150 billion per year. The goal of the air quality program is to provide the U.S. with ozone, particulate matter and other pollutant forecasts with enough accuracy and advance notice to allow people to limit harmful effects of poor air quality, saving lives and reducing the number of air quality-related asthma attacks, eye, nose, and throat irritation, heart attacks and other respiratory and cardiovascular problems.

NOAA's Role

NOAA's National Weather Service (NWS) currently provides forecast guidance for ozone and smoke based on numerical atmospheric predictions updated twice daily. These predictions are produced by linked models for weather prediction, developed by NOAA's NWS, and for air quality, developed by NOAA's Office of Oceanic and Atmospheric Research (OAR), run operationally on supercomputers at NOAA's National Centers for Environmental Prediction (NCEP). Predictions are at 12 kilometer grid resolution, and provide information for people in cities, suburbs and rural areas alike, at hourly intervals through midnight the next day. The air quality forecast guidance is provided in digital and graphical formats on NWS data servers. Graphical forecast guidance for ground-level Ozone (O3) are displayed as 1-hour and 8-hour average concentrations for the eastern U.S.(the Mississippi Valley eastward). Experimental ozone forecast guidance for the contiguous 48 states is also provided.

Lab experiments to study chemical reactions

The Smoke Forecast Guidance shows predicted smoke transport from large fires that are revealed in NOAA/NESDIS satellite imagery, and based again on linked NWS and OAR models run on NCEP supercomputers. The smoke forecast guidance is displayed graphically for all 50 states. Two graphics are generated, showing hourly predictions of 1-hour average concentrations of fine particulate matter, diameter 2.5 microns or less (PM 2.5), in smoke in (1) the surface layer, and in (2) the atmospheric column, as column-averaged smoke. In time, the Air Quality Forecast Guidance will expand Nationwide and will include quantitative predictions of total PM 2.5, which comes from many sources, especially air pollution and dust, in addition to smoke.

EPA's Role

The EPA works with state and local air quality agencies, as well as the private sector, to gather air quality data and interpret its health impacts with a national network for air quality monitoring and a national inventory of emissions data. This data is provided to NOAA for its forecasting capability described above. State and local air quality agencies use this guidance to issue air quality forecasts and Air Quality Index predictions for some 300 participating communities across the U.S. Typically, these take the form of an alert level issued for the next day, based on expected worst-case air quality. The EPA compiles and nationally distributes this state and local information. The private sector uses and disseminates this information to the public as well.

Why Forecast Ozone and Particulate Matter?

Ground-level ozone (O3) is a product of nitrogen oxides (NOx) and volatile organic compounds (VOCs) in the presence of heat and sunlight. Motor vehicle exhaust, industrial emissions, gasoline vapors, and chemical solvents are among the major sources of NOx and VOCs responsible for harmful buildup of ground-level ozone. Even at low concentrations, ozone can trigger a variety of health problems such as lung irritation and inflammation, asthma attacks, wheezing, coughing, and increased susceptibility to respiratory illnesses. Particulate matter (PM), or airborne particles, include dust, dirt, soot, and smoke. Some particles are directly emitted into the air by, for example, cars, trucks, buses factories, construction sites, and wood burning. Other particles are formed in the air when gases from burning fuels react with sunlight and water vapor. Such gases, from incomplete combustion in motor vehicles, at power plants and in other industrial processes, contribute indirectly to particulate pollution. PM can cause chronic bronchitis, asthma attacks, decreased lung function, coughing, painful breathing, cardiac problems and heart attacks, as well as a variety of serious environmental impacts such as acidification of lakes and streams and nutrient depletion in soils and water bodies. For more information on Air Quality Products, please go to http://www.weather.gov/ost/air_quality/.

For additional information on what you can do to minimize the affects of poor air quality, and to improve the quality of the air we breathe, go to http://www.weather.gov/airquality/.