USEPA/OAQPS MeteorologicalModeling AnalysesAd Hoc Met Modeling MeetingJuly 30, 2002Pat DolwickUSEPA: OAQPS/EMAD/AQMGNOAA: ARL/ASMD/APSBOverviewImportance of Meteorological Modelingoften-overlooked, relative to emissions/AQincreasingly important in PM/visibilityRecent Meteorological Analyses @ EPA1996 continental U.S. MM5 data set (MCNC)U.S./Canada modeling (July 1995 MM5)Present Meteorological Analyses @ EPAsupport upcoming regulatory actionsimprove overall quality of Federal/State/Local/RPOmeteorological activitiesThree-legged stool analogyEmissions estimatesEmissions estimatesMeteorological InputsMeteorological InputsAQM: physics/chemistryAQM: physics/chemistryAir Quality ModelAir Quality ModelThree-legged stool analogy (the hidden truth)AQ ModelDecision MakerImportance of Meteorological Modeling(often overlooked)Case Study: EPA Technical AnalysesEmissions: develop/evaluate modeling tools;significant contractor resources; dedicated groupw/in EMAD (EFIG)Air Quality Modeling: develop/evaluate modelingtools; significant contractor resources; dedicatedgroup w/in EMAD (AQMG)Meteorology: limited & sporadic contractorresources; extremely limited staff resourcesTends to be rule rather than exceptionImportance of Meteorological Modeling(increasing for PM/Vis)Migrating from ozone to 1-atmosphereKey parameters were generally well understoodfor local/regional ozone simulations. (PBL, wind,UV, T)For PM/visibility, accurate representations ofhumidity, clouds, and precipitation will be criticalfor successful AQ model applications.Importance of Meteorological Modeling(increasing for PM/Vis)Importance of Meteorological Modeling(increasing for PM/Vis)Importance of MeteorologicalModeling (increasing for PM/Vis)Importance of Meteorological Modeling(increasing for PM/Vis)Importance of Meteorological Modeling(increasing for PM/Vis)Recent Meteorological Analyses @ USEPAContinental U.S. MM5 Application: 1996MM5 v2.12, 108/36 km, 23 layersapplied by MCNCMRF, K-F, simple ice, long & short-wave radiationresources did not permit diagnostic testingmodel evaluation (low T, low PBL, winds in West)used in Tier-2, Heavy-Duty Diesel, Clear Skiesdata also sent to multiple other groups(WRAP, TVA, Trinity Consulting, Ontario, AER, etc.)Recent Meteorological Analyses @ USEPAEastern U.S. MM5 application: July 1995MM5 v3.5, 108/36/12/04 km, 28 layersapplied at EPABlackadar, K-F, simple ice, surface radiationschedule permitted only limited diagnostic testingonly qualitative model evaluationused in US/Canada annex modeling, proof-ofconceptRecent Meteorological Analyses @ USEPA(July 1995, Eastern US)Recent Meteorological Analyses @ USEPA(July 1995, Eastern US)Recent Meteorological Analyses @ USEPA(July 1995, Eastern US)Recent Meteorological Analyses @USEPA (July 1995, Eastern US)Developing Meteorological Input Data for AirQuality Modeling AnalysesGoal: development of high-quality, gridded meteorological datasetsthat can be used to support urban,regional, and national air qualitymodeling exercises over the United States.Alpine Geophysics is the primary contractor for the work assignmentwith assistance from Atmospheric, Meteorological and EnvironmentalTechnologies, LLC (ATMET)The work assignment consists of four major activities:Recommend meteorological model evaluation methodologiesInvestigate the utility of alternative meteorological data setsPerform episodic, 12km MM5 simulationover the eastern U.S. (July/Aug2001)Perform an annual, continental U.S. MM5 simulation (2001)Annual Application of MM5 to the ContinentalU.S.Goal: development of gridded meteorological datasets that can be usedto support national air quality modelingA modeling protocol has been developed and is availableVersion 3.5 of MM5Model to be run in 5-day intervals, with 12 hours of overlap for initializationRPO grid projection (40°, -97° centroid; true latitudes of 33° and 45°)34 vertical layers; surface layer 38 mKey model physics options (pending final determination):Kain-Fritsch cumulus parameterization,Blackadar PBL scheme,Dudhia Simple Ice microphysics,RRTM radiation scheme, andthe P-X land surface model (???).Annual Application of MM5 to the ContinentalU.S.The performance of the model will be assessed via an operationalevaluation and a scientific evaluation:Operational: parameters will include winds, temperature, moisture, cloud,precipitation, etc.Operational: statistics will include bias,error, RMSE, index of agreement, comparionsof the mean values and standard deviations, skill scores, etc.Operational: evaluation will be conductedon national, RPO, and State levels forseveral time scales.Scientific: several diagnostic tests have beenidentified to provide additional insightinto model performance (i.e., assess the sensitivity of the results to certain physicsoptions).Several diagnostic/sensitivity testshave been completed (testing isdone for two 20-day episodes in February and July)use of larger domain with NNRP initialization data; use of “ZFAC” mods; no FDDA;double FDDA; alternative land surface models; alternative microphysics schemes(Reisner).