Report

U.S. EPA’s Evaluation of Long Range Transport Models Ralph E. Morris ENVIRON International Corporation Template A&WMA CPANS Conference University of Calgary April 23-24, 2012 ENVIRON’s work for USEPA LRT Model Evaluation Study • Mesoscale Model Interface (MMIF) tool – Pass WRF/MM5 meteorological model output directly to CALPUFF with minimal modification (CALMET not needed) • Document evaluation of CALPUFF and other LRT dispersion models using tracer field study data – EPA performed all of the model simulations • Perform a Consequence Analysis analyzing CALPUFF and • CAMx for LRT AQ and AQRV Evaluate CALPUFF, SCICHEM and CAMx using atmospheric plume chemistry data 773 San Marin Drive, Suite 2115, Novato, CA 94998 P: 415-899-0700 F: 415-899-0707 www.environcorp.com 2 MMIF Tool for CALPUFF Met Inputs • CALPUFF needs • meteorological variables defined at grid cell centers WRF uses an Arakawa C grid configuration – U and V winds defined on cell edges – Other met variables defined on cell centers – Impossible to pass-through winds directly to CALPUFF • Some level of interpolation is needed – MMIF elected to interpolate winds to cell centers Arakawa C v, Ky (i, j) T, p, q, Kv u, Kx (i-1 , j) (i, j) u, Kx (i, j) (i, j-1 ) v, Ky 3 Inert Tracer Experiment Evaluation • LRT transport and dispersion algorithms evaluated using inert tracer field experiments – Release known amount of inert tracer – Measure at downwind receptor sites – Evaluate LRT models ability to predict tracer concentrations • Examples of past tracer experiment evaluation studies – – – – – 1986 8-model study 1990 Rocky Mountain Acid Deposition Model Assessment 1998 EPA evaluates CALPUFF using 2 tracer experiments 1998 IWAQM Phase II recommendations 1994 European Tracer Experiment (ETEX) ATMES = real time model evaluation ATMES-II historical model evaluation 773 San Marin Drive, Suite 2115, Novato, CA 94998 P: 415-899-0700 F: 415-899-0707 www.environcorp.com 4 USEPA LRT Tracer Test Evaluation • EPA evaluated CALPUFF using five tracer test field study measurements: – – – – 1975 Savannah River Laboratory (SRL75) 1980 Great Plains (GP80) 1983 Cross-Appalachia Tracer Experiment (CAPTEX) 1994 European Tracer Experiment (ETEX) • Compare CALPUFF GP80/SRL76 with1998 EPA study – Determine how advances in CALPUFF improve performance • For some experiments compare multiple LRT dispersion models: – CALPUFF; HYSPLIT; FLEXPART; SCIPUFF; CAMx; CALGRID 773 San Marin Drive, Suite 2115, Novato, CA 94998 P: 415-899-0700 F: 415-899-0707 www.environcorp.com 5 GP80 and SRL 75 Tracer Experiments GP80 • Receptor arcs at 100 km and • • 600 km Evaluate CALPUFF separately on each arc using different configurations Compare with 1998 study SRL75 • One 100 km receptor arc • Evaluate CALPUFF using • different configurations Compare with 1998 study 6 CAPTEX and ETEX CAPTEX (CTEX3 & CTEX5) ETEX • Many CALMET configurations • Evaluate LRT models using default configuration “out-of• Evaluate CALMET & MM5 & • CALPUFF Evaluate LRT models using default configuration • the-box” Additional CAMx. HYSPLIT and CALPUFF sensitivity tests 7 Number LRT Dispersion Model Runs Test CALPUFF SCIPUFF HYSPLIT FLXPRT CAMx CALGRD GP80 100km 36 0 0 0 0 0 GP80 600km 41 0 0 0 0 0 SRL75 100km 21 0 0 0 0 0 CAPTEX CTEX3a 25 0 0 0 0 0 CAPTEX CYEX5a 24 0 0 0 0 0 CAPTEX CTEX3b 1 1 9 1 16 1 CAPTEX CTEX5b 1 1 9 1 16 1 ETEX 8 1 9 1 16 0 Total 157 3 27 3 48 3 8 Cross Appalachian Tracer Experiment (CAPTEX) • 5 tracer releases from Dayton, OH or Sudbury, Canada – CTEX3 – Oct 2, 1983 – CTEX5 – Oct 25-26, 1983 • Six LRT Models Evaluated – CALPUFF & SCIPUFF – HYSPLIT & FLEXPART – CAMx & CALGRID • Meteorological Evaluation – Evaluate MM5 and CALMET – Identify best performing CALMET settings – Used in to determine USEPA’s recommended CALMET settings 9 CTEX3: CALMET Sensitivity Tests Evaluation • 31 CALMET Sens Tests : • 3 MMIF Sensitivity Tests: – MM5 @ 80, 36 & 12 km How MM5 is used within CALMET – MM5 @ 36, 12 & 4 km • CALMETSTAT to evaluate wind speed and direction – First Guess – Step 1 Winds – None – CALMET @ 18, 12 & 4 km – RMAX1/RMAX2 (OA) Wind Speed A = 500/1000 Wind Direction B = 100/200 – EPA Recommended C = 10/100 D = NOOBS Temperature Humidity – Compare against common benchmarks used to interpret MM5/WRF evaluation Root Mean Squared Error (RMSE) Mean Normalized Bias (NMB) Index of Agreement (IOA) Mean Normalized Gross Error (MNGE) Mean Normalized Bias (MNB) Mean Normalized Gross Error (MNGE) Mean Normalized Bias (NMB) Index of Agreement (IOA) Mean Normalized Gross Error (MNGE) Mean Normalized Bias (NMB) Index of Agreement (IOA) ≤ 2.0 m/s ≤ ±0.5 m/s ≥ 0.6 ≤ 30° ≤ ±10° ≤ 2.0 K ≤ ±0.5 m/s ≥ 0.8 ≤ 2.0 g/kg ≤ ±1.0 g/kg ≥ 0.6 10 WS & WD Bias/Error CALMET w/ 12 km MM5 EXP4 & EXP6 = 12 & 4 km CALMET A,B,C,D: RMAX1/RMAX2 = 500/1000, 100/200, 10/100, 0/0 8 6 4 2 0 -2 -4 -6 -8 EXP 6D EXP 6C EXP 6B EXP 6A EXP 4D EXP 4C MM5_12km WS Bias WD Bias (deg.) EXP 4B MM5_12km EXP 6D EXP 6C EXP 6B EXP 6A EXP 4D EXP 4C EXP 4B EXP 4A WSBias BiasIOA (ms^-1) Gross Error (ms^-1) WS (ms^-1) EXP 4A 0.6 0.4 0.2 0.0 -0.2 -0.4 -0.6 WD Bias WS Gross Error (ms^-1) WD Gross Error (deg.) 35 2.5 30 2 25 1.5 20 1 15 10 0.5 5 MM5_12km EXP 6D WD Error EXP 6C EXP 6B EXP 6A EXP 4D EXP 4C EXP 4B MM5_12km EXP 6D EXP 6C EXP 6B EXP 6A EXP 4D EXP 4C EXP 4B EXP 4A WS Error EXP 4A 0 0 11 Conclusions CTEX3 CALMET Model Performance • CTEX3 MM5 and CALMET wind model performance: – The EPA-recommended settings of RMAX1/RMAX2 (100/200, “B” Series) produced best wind model performance. – Use of 4 km grid resolution in CALMET tended to produce better wind model performance than 12 or 18 km. Can’t say anything about finer grid resolution than 4 km. – The CALMET wind model performance was better using the 12 and 36 km MM5 data as input than using the 80 km MM4 data. • CTEX5 also found RMAX1/RMAX2 = 100/200 best wind • performance Note: Not an independent evaluation since WS/WD obs were also used as input to most CALMET tests 773 San Marin Drive, Suite 2115, Novato, CA 94998 P: 415-899-0700 F: 415-899-0707 www.environcorp.com 12 CTEX3: CALPUFF/CALMET Sens Tests • CALPUFF evaluation using • 25 CALMET sensitivity tests – CALPUFF runs for CTEX3 tracer release – Evaluate CALPUFF using ATMES-II 12 statistical performance metrics – Determine which CALMET configuration results in best CALPUFF performance • CALPUFF evaluation using 3 MMIF met inputs Evaluate using ATMES-II statistical performance metrics: – Spatial, Temporal & Global – Bias and Error – Scatter – Correlation – Cumulative Distribution Statistical Metric Perfect Score Definition Spatial Statistics AM AP FMS Figure of Merit in Space (FMS) AM AP 100 % 100% Global Statistics Normalized Mean Squared Error (NMSE) Pearson’s Correlation Coefficient (PCC or R) 1 NMSE P i N PM M R i M M Pi P i 2 0% 1.0 i M i M 2 P i P P M Fractional Bias (FB) FB 2 B Kolmogorov-Smirnov (KS) Parameter KS Max C M k C Pk 2 0% 0% 13 ) R Two i 2 2 Composite Statistics for Ranking Mi M Pi P Models 2), bias (FB), • RANK combines statistics for correlation (R FB 2 B P M spatial (FMS) and cumulative distribution (KS) with M4.0 C Pk KS Max k perfect model giving scoreCof RANK R 2 1 FB / 2 FMS / 100 1 KS / 100 RANK statistics needs to be revised, propose replace FB w/ NMSE • AVERAGE averages the N model’s rankings from 1 to N across the 11 ATMES-II statistics with the best model being model with lowest score closest to 1.0 – 1.0 = model is highest ranked model across all 11 ATMES-II statistical metrics 14 CALPUFF MPE using 12 km MM5 EXP4 & EXP6 = 12 & 4 km CALMET A,B,C,D: RMAX1/RMAX2 = 500/1000, 100/200, 10/100, 0/0 Normalized Mean Square Error (NMSE) Figure of Metric in Space (FMS) (Perfect = 100%) (Perfect = 0) 40% 35% 30% 25% 20% 15% 10% 5% 0% 12K MMIF EXP 6D EXP 6C EXP 6B EXP 6A EXP 4D EXP 4C EXP 4B EXP 4A 12K MMIF EXP 6D EXP 6C EXP 6B EXP 6A EXP 4D EXP 4C EXP 4B EXP 4A 60 50 40 30 20 10 0 Rank (RANK) (Perfect = 4) Fractional Bias (FB) 1.6 (Perfect = 0) 1.4 1.2 1.4 1.2 1 0.8 0.6 0.4 0.2 0 1 0.6 (1-KS/100) 0.4 FMS/100 0.2 (1-FB/2) R^2 12KM_MMIF EXP6D EXP6C EXP6B EXP6A EXP4D EXP4C EXP4B 0 EXP4A 12K MMIF EXP 6D EXP 6C EXP 6B EXP 6A EXP 4D EXP 4C EXP 4B EXP 4A 0.8 15 CTEX3 CALPUFF Evaluation Conclusions • The CALPUFF MMIF best performing for CTEX3 (worst for CTEX5). • The CALPUFF/CALMET RMAX1/RMAX2 = 100/200 worst performing RMAX1/RMAX2 configuration – Contrast to best performing CALMET configuration for WS/WD • CALPUFF/CALMET with higher MM5 resolution (36 and 12 km) performs better than using 80 km MM4 data. • Generally, CALPUFF/CALMET using 4 km resolution performs better 773 San Marin Drive, Suite 2115, Novato, CA 94998 P: 415-899-0700 F: 415-899-0707 www.environcorp.com 16 CTEX3 Six LRT Model Evaluation • Use common 36 km MM5 meteorology in all models • Run 6 LRT models out-of-the-box using default • • configuration Evaluate using ATMES-II statistical metrics 6 LRT dispersion models evaluated: – Two Lagrangian Puff Models CALMET (w/ MMIF, best performing for CTEX3) and SCIPUFF – Two Lagrangian Particle Models FLEXPART and HYSPLIT – Two Eulerian grid models CAMx and CALGRID 773 San Marin Drive, Suite 2115, Novato, CA 94998 P: 415-899-0700 F: 415-899-0707 www.environcorp.com 17 CTEX3 Tracer Test LRT Model Evaluation (best performing model has lowest value) 18 CTEX3 Tracer Test LRT Model Evaluation (best performing model has highest value) 19 Conclusions of EPA LRT Evaluation (1 of 3) • GP80 Tracer Field Experiment – Using different valid CALMET configurations, the maximum CALPUFF concentrations vary by factor of 3 Need standardized model configuration for regulatory modeling – Since less options, less variation using MMIF – CALPUFF “SLUG” near-field option needed to reproduce “good” model performance on 600 km arc from 1998 EPA study Raises question of validity of 1998 EPA study since SLUG typically not used for LRT dispersion modeling • SRL75 Tracer Field Experiment – Fitted Gaussian plume evaluation approach can be flawed The a priori assumption that the observed plume has a Gaussian plume distribution may not be valid at LRT distances 773 San Marin Drive, Suite 2115, Novato, CA 94998 P: 415-899-0700 F: 415-899-0707 www.environcorp.com 20 Conclusions of EPA LRT Evaluation (2 of 3) • CAPTEX Tracer Field Experiment – RMAX1/RMAX2 = 100/200 (EPA recommendation) produces best CALMET WS/WD but worst CALPUFF tracer performance EPA needs help from modeling community to identify regulatory CALMET settings – CALPUFF/MMIF performs better than CALPUFF/CALMET for CTEX3 but worst for CTEX5 – CTEX3: CAMx/SCIPUFF perform best followed by CALPUF/FLEXPART with HYSPLIT/CALGRID worst – CTEX5: CAMx/HYSPLIT performs best followed by SCIPUFF/FLEXPART with CALPUFF/CALGRID worst 773 San Marin Drive, Suite 2115, Novato, CA 94998 P: 415-899-0700 F: 415-899-0707 www.environcorp.com 21 Conclusions of EPA LRT Evaluation (3 of 3) • ETEX Tracer Field Experiment – Objective was to evaluate models run with default configuration using common 36 km MM5 inputs Exception was to use more all hours puff splitting in CALPUFF rather than default of once per day • CAMx, HYSPLIT & SCIPUFF perform best • FLEXPART & CALPUFF perform worst – Sensitivity tests for CALPUFF, CAMx and HYSPLIT CALPUFF more aggressive puff splitting didn’t help CAMx found default configuration best performing HYSPLIT found some hybrid particle/puff configurations perform better than particle-only default 773 San Marin Drive, Suite 2115, Novato, CA 94998 P: 415-899-0700 F: 415-899-0707 www.environcorp.com 22 Questions? • Full draft LRT tracer report available on EPA SCRAM website (consequence analysis & plume evaluation to come) 773 San Marin Drive, Suite 2115, Novato, CA 94998 P: 415-899-0700 F: 415-899-0707 www.environcorp.com 23