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VERIFICATION OF SURFACE LAYER OZONE FORECASTS IN THE NOAA/EPA AIR QUALITY FORECAST SYSTEM IN DIFFERENT REGIONS UNDER DIFFERENT SYNOPTIC SCENARIOS
Citation:
TSIDULKO, M., J. T. MCQUEEN, G. DIMEGO, P. C. LEE, R. MATHUR, K. L. SCHERE, J. PLEIM, T. L. OTTE, D. KANG, M. SCHENK, J. GORLINE, AND P. M. DAVIDSON. VERIFICATION OF SURFACE LAYER OZONE FORECASTS IN THE NOAA/EPA AIR QUALITY FORECAST SYSTEM IN DIFFERENT REGIONS UNDER DIFFERENT SYNOPTIC SCENARIOS. Presented at 7th Conference on Atmospheric Chemistry American Meteorological Society, San Diego, CA, January 09 - 13, 2005.
Impact/Purpose:
The objectives of this task include: (1) to continuously evaluate and analyze the forecast results to provide diagnostic information on model performance and inadequacies to guide further evolution and refinements to the CMAQ model, and (2) extending the utility of the daily air quality forecast model data being produced by NOAA's National Weather Service (NWS) as part of a NOAA/EPA collaboration in air quality forecasting, to EPA mission-oriented activities. These objectives include developing and maintaining a long-term database of air quality modeling results (ozone and PM2.5), performing periodic analysis and assessments using the data, and making the air quality database available and accessible to States, Regions, RPO's and others to use as input data for regional/local scale air quality modeling for policy/regulatory purposes.
Description:
An air quality forecast (AQF) system has been established at NOAA/NCEP since 2003 as a collaborative effort of NOAA and EPA. The system is based on NCEP's Eta mesoscale meteorological model and EPA's CMAQ air quality model (Davidson et al, 2004). The vision behind this system is to provide national guidance for ozone, particulate matter and other pollutants with acceptable accuracy. As a first stage of the project, ozone concentrations have been predicted on a real-time basis since summer 2003 for the Northeast US. Based on the initial series of experiments, an updated version of the AQF system is set to operational status by the autumn of 2004. This paper discusses a detailed verification of the ozone forecasts for selected periods during summer 2004.
Verification presented in this paper is done for the Northeast operational domain (Fig. 3). To create a capability for evaluating ozone, surface layer ozone concentrations from EPA AIRNOW measurements and CMAQ forecasts were incorporated into NCEP's Forecast Verification System (FVS) (Brill, 2004, DiMego et al, 2004). The AIRNOW network reports 1hr average and 8hr average surface ozone concentrations. Also, maximum values of these concentrations during the day can be derived. All these parameters are a subject for statistical evaluation. In this paper, however, only 1 hr average concentrations are verified. In FVS, the CMAQ predicted concentrations are interpolated to the observation points. Average statistics (e.g. bias, root mean square error, correlation, etc) are computed for the North East Coast, South East Coast, Mid-West, Gulf of Mexico and several other areas. Statistics for critical thresholds of ozone concentration are also computed.
The research presented here was performed under the Memorandum of Understanding between the U.S. Environmental Protection Agency (EPA) and the U.S. Department of Commerce's National Oceanic and Atmospheric Administration (NOAA) and under agreement number DW 13921548. Although it has been reviewed by EPA and NOAA and approved for publication, it does not necessarily reflect their policies of views.