84th AMS Annual Meeting

Tuesday, 13 January 2004: 4:15 PM
The Air Quality four-Panel Chart
Room 612
William F. Ryan, Penn State University, University Park, PA; and G. M. Bridgers, D. D. Salkovitz, and C. A. Piety
Poster PDF (1.2 MB)
Meteorologists use a standard set of forecast maps to quickly orient themselves to current conditions and to identify critical forecast issues for deeper analysis. These charts traditionally focus on a set of variables, and vertical levels, of interest to forecasting on the synoptic scale. The parameters displayed typically include: jet stream winds, mid-level vorticity, low-level temperature and moisture. In recent years, there has been an remarkable increase in the number of state and local governments issuing air quality forecasts. Currently, air quality forecasts are issued for several hundred jurisdictions (see, http://www.epa.gov/AIRNOW/). While synoptic scale phenomena displayed in standard 4-panel charts are of interest to air quality forecasters, the most severe pollution events, where forecast skill is critical, tend to occur in quiescent synoptic regimes dominated by mesoscale and local boundary layer processes. This paper addresses the need for an additional standard set of charts that address factors specific to air quality forecasts. One critical factor is the persistence of the forecasted pollutants. Ozone (O3) and PM2.5, for example, have lifetimes of several days and can be transported long distances. As a result, knowledge of current conditions, and transport patterns, are critical to determining the initial, or background, load of the pollutant. As emissions of pollutants are relatively constant day-to-day, the volume into which the pollutants are mixed becomes important. Therefore, knowledge of the depth and evolution of the boundary layer are important. To the extent the pollutant of interest is produced photo-chemically, cloud cover can modulate concentrations. In this paper, a variety of possible standard charts, and options, are discussed and recommendations for standard output from the experimental NOAA air quality forecast model (http://www.nws.noaa.gov/ost/air_quality/index.htm) are made.

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