Three-State Air Quality Study (3SAQS)

Three-State Data Warehouse (3SDW)

2011 WRF Modeling Model Performance Evaluation Summary

University of North Carolina (UNC-IE)Cooperative Institute for Research in the Atmosphere (CIRA)

ENVIRON International Corporation (ENVIRON)

June 19, 2014

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3SAQS WRF MPE Summary• Objective: Develop best possible regional meteorology database

for annual 2011 air quality modeling• Nested 36/12/4-km WRF-ARW 3.5.1 with configuration optimized

for the intermountain West • Single configuration across the entire year (no special wintertime

version)• Standard and extended model performance evaluation metrics

focused on the 4-km domain• MPE conclusion: 3SAQS 2011 WRF application exhibited

reasonably good model performance that was as good or better than other recent prognostic model applications used in air quality planning

WRF Domain and Configuration

• Standard (40N-97W) Lambert-Conformal Conic projection

• CONUS 36km (165x129)• WestJump 12km

(256x253)• 3SAQS 4km (301x361)• 37 layers to 50 mb (12m

surface layer)

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Configuration Tests

• First-order simulations on all three domains for January 1-7 and July 1-7, 2011 to test different configurations:– NAM vs ECMWF Initial and boundary conditions (ICBC)– 2006 NCLD vs USGS land-use land cover (LULC) data– Noah-YSU vs PX-ACM2 land surface/boundary layer

schemes– Obs nudging coefficient and network sensitivities

• Ultimately settled on the same configuration as WestJumpAQMS 2008 WRF

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Evaluation Approach

• AMET used to evaluate surface temperatures, winds, and mixing ratios against MADIS observations

• Wintertime evaluation of snow cover and snow depth• PRISM precipitation evaluations• Compared results to performance benchmarks (bias

and error) for Western U.S. regional met modeling• Evaluation focused on seasonal performance in CO,

UT, WY, and 4-km domain (average of all monitors within each area)

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Winter 2011 Performance

• 2-m Temperatures– Slight cool bias across all stations in the 4-km domain (driven by CO,

WY, NM)– Warm bias at UT stations in January exceeds performance benchmark

of 1°K– January nighttime warm bias at UT stations as much as 5°K; likely

indicates inability of WRF to simulation temperature inversions in complex terrain

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Winter 2011 Performance

• Wind speed– Negative bias across all stations in the 4-km domain – Benchmark performance (0.5 m/s) missed in 4-km

domain in January and February– Benchmark performance consistently missed in WY

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Winter 2011 Performance

• Mixing Ratio– WRF is generally too wet in the winter months.– All states driven by high daytime biases– Biases within benchmark threshold of 1.0 g/kg

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Summer 2011 Performance

• Temperature– The low/zero bias in the 4-km domain is resulting from a

cancelling effect of biases across the domain– Biases within benchmark threshold of 1.0 K– WRF simulates the diurnal variability well but tends to be

cool at night and warms too quickly after sunrise

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Summer 2011 Performance

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Summer 2011 Performance

• Wind Speed– Negative bias throughout the three-state domain– Biases exceed the benchmark threshold in CO and WY– RMSE close to the benchmark threshold for most

months

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Summer 2011 Performance

• Mixing Ratio– WRF is generally too dry in the summer months– Biases within benchmark threshold of 1.0 g/kg– May indicate a known problem with WRF’s ability

to simulate summertime convection

WRF Monthly Performance Summaries2-m Temperature

CO UTWY

WRF Monthly Performance SummariesWind Speed

CO UTWY

WRF Monthly Performance SummariesMixing Ratio

CO UTWY

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3SAQS 2011 WRF MPE Winter Ozone

• 2011 WRF simulation included several high winter ozone events in Upper Green River Basin (URGRB) in southwest Wyoming during the Upper Green River Ozone Study (UGWOS)

• 13 ozone exceedance days (76 ppb or higher) occurred during February and March 2011– 123 ppb on Mar 2, 2011– 121 ppb on Mar 3, 2011– 121 ppb on Mar 12, 2011

UGWOS Monitoring Sites

High Winter Ozone Days 2011 UGWOS

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Winter Ozone Conditions

• Snow on ground (white)• Clear skies or little clouds• Slow to Stagnant winds• Strong shallow (~100 m) inversion

2011 Winter Ozone WRF Evaluation

• Use UGWOS special study and routine NOAA ds3505 surface met obs in SWWY

• Soccer plots for Feb and Mar and SWWY domain

• Vertical temperature profiles

• 3SAQS 2011 WRF run not configured for winter ozone conditions

WRF Wind MPE 9 Sites UGRB

WRF Wind MPE ds3505 sites UGRB

Mar 1, 2011 1500 (Max O3 =121 ppb)

Mar 2, 2011 1500 (Max O3 =123 ppb)

Mar 10, 2011 1500 (Max O3 = 84 ppb)

Mar 10, 2011 1500 (Max O3 = 84 ppb)

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Winter Ozone WRF Conclusions• Need more focused evaluation for high ozone days• Some promise with low bias for winds and

temperature– Large error not unexpected given slow wind speed

• Vertical temperature matched reasonable well– Worse near the surface

• 3SAQS 2011 WRF 36/12/4 km can provide starting point for focused higher resolution WRF model of winter ozone episodes using winter ozone WRF configuration