1. The Influence on CMAQ Modeled Wet and Dry Deposition of Advances in the CMAQ Systems for Meteorology and Emissions Robin Dennis, Jesse Bash, Kristen Foley, Rob Gilliam, and Rob Pinder Atmospheric Modeling and Analysis Division NERL, EPA 2013 NADP Annual Meeting and Symposium Park City, Utah October 9, 2013

2. 1 Four Improvements Focused on Nitrogen Revised meteorology: convective precipitation, inclusion of woody wetlands and fix to albedo Lightning NO X inclusion CAFO emission profile revision Bi-directional NH 3 inclusion Incremental testing of improvements using simulations for 2006 The influence on CMAQ modeled wet and dry deposition of advances in the CMAQ systems for meteorology and emissions

3. 2 Convective Precipitation: Used a different convective trigger algorithm (Ma & Tan 2009) Decreased the precipitation bias significantly from +12% to +1% Not much change in variability/error Better balance in the model for wet Did cause larger bias for wet NH 4 from -13% to -20% (remember -20%) Default: NMB = 12% RMSE = 30 cm New Trigger: NMB = 1% RMSE = 29 cm Observed Precipitation (cm) Modeled Precipitation (cm)

4. 3 NMBNMERMSE No LNOx-14%24%2.4 LNOx -5%22%2.3 Precipitation corrected Lightning NO X Sensitivity: Wet NO 3 Deposition Only summer time months affected kg/ha 2006 Wet Total-Nitrate without Lightning2006 Wet Total-Nitrate with Lightning

5. 4 Revised CAFO Diurnal Emissions Profile Responsive to local meteorology (turbulence; temperature)

6. 5 18% reduction in dry Reduced-N deposition over CONUS domain (Jan, Feb, July) 9% increase in wet Reduced-N deposition over CONUS domain (Jan, Feb, July) Revised CAFO Diurnal Profile Fraction Wet Red-N Dry Red-N 2006 New CAFO Profile/Static Profile

7. 6 8.3% decrease in total Reduced-N deposition (Jan, Feb, July) 0.4% increase in total Oxidized-N deposition (Jan, Feb, July) Fraction Total Red-N Total Ox-N 2006 New CAFO Profile/Static Profile

8. 7 Bi-Directional NH 3 Exchange EPIC Environmental Policy Integrated Climate model Use CMAQ X

9. 8 19% increase in wet Red-N deposition 30% reduction in dry Red-N deposition NMBNMERMSE Base-20%31%0.90 BiDi -4%28%0.85 Bi-Directional NH 3 Exchange Fraction (remember -20%) No Statistics for Dry Wet Red-N Dry Red-N 2006 NH 3 BiDi/Unidirectional Base

10. 9 10% reduction in total Reduced-N deposition Fraction Bi-Directional NH 3 Exchange Total Red-N 2006 NH 3 BiDi/Unidirectional Base

11. 10 Combined Changes (3 of 4): Meteorology /CAFO profile /Bi-directional NH 3 Large Improvement in NH X Wet Deposition Bias NMBNMERMSE V5.0 Base-18%29%0.88 V5.0.2 Bidi -4%28%0.85 kg/ha

12. 11 NMBNMERMSE V5.0 Base-4%20%2.2 V5.0.2 Bidi-5%21%2.3 NMBNMERMSE V5.0 Base+7%22%3.1 V5.0.2 Bidi-5%22%3.0 Significant improvement in nitrate wet deposition from lightning NO X (-14% to -5%) already factored into these runs Flip of bias for wet sulfate deposition kg/ha

13. 12 -17.1% decrease on CONUS 3.1% increase on CONUS MOBEL6 vs MOVES -5.6% decrease on CONUS Fraction 3 Changes: Convective precipitation; CAFO upgrade; Bi-Di NH 3 Total Deposition Total Red-N Total Ox-N Total-N

14. 13 NMBNMERMSE V5.0 Base19%113%1.5 V5.0.2 Bidi 4%73%1.0 Significant improvement in nitrate air concentration bias and error, both annually and seasonally/monthly; Improved sulfate error, monthly and annually (1.4 ->1.0); Improved ammonium error, monthly and annually (1.3->0.9) Bias at IMPROVE sites of Nitrate Air Concentrations Monthly Air Concentration Statistics Aggregate Statistics

15. 14 NMBNMERMSE V5.0 Base 8%31%0.83 V5.0.2 Bidi 8%27%0.68 Improvement in monthly total-nitrate air concentration bias and error, reducing annual RMSE; no change in annual bias Monthly Air Concentration Statistics Aggregate Statistics Bias at CASTNet sites of Total-Nitrate Air Concentrations

16. Overall Sense Made some real process-level improvements –Biases are down/improved in general (particularly wet) –Lower precipitation bias means balance in model can be better tested; we think the balance is better Long-range transport is up, in general, especially for NH 3 Increased N deposition in West where have the largest under-prediction in wet deposition CAFO and bi-directional changes do not add linearly Annual and monthly error in comparisons for particles are improved, for NO 3 - both bias and error improved Still more to be done Creating a consistent data set for 2002 to 2011/2012 (2004?) 15

17. Thanks 16

18. Extra Slides 17