1. Project: Improving Air Quality Modeling for the Wasatch Front/Cache Valley Winter Air Pollution Episodes Erik Crosman 1, John Horel 1, Lance Avey 2, Chris Foster 1, Erik Neemann 1, Brian Blaylock 1, 1 University of Utah Department of Atmospheric Sciences 2 Utah Division of Air Quality

2. Study Objectives Determine appropriate WRF atmospheric model configurations including treatment of the underlying surface to improve simulations of wintertime cold pool events along the Wasatch Front and in the Cache Valley that lead to high PM2.5 pollution Collaborate with Utah DAQ staff to identify and simulate selected cold-air pool episodes to be used in PM2.5 SIP development

3. Research to Improve Wintertime Cold Air Pool Simulations in 4 Key Areas Surface state characterization (e.g., snow, albedo, land use, vegetation) Initialization Cloud microphysics Boundary-layer turbulence

4. October 15 2014: Complete identification of possible prior winter case studies with DAQ staff; Case 1 choosen: PCAPS IOP5 (Jan 1-9 2011) Case 2 uncertain: PCAPS IOP1 (mix-out midway through episode?) November 15 2014: Graduate student attends CMAQ workshop to become familiar with atmospheric modeling needs required for CMAQ during late October. Chris Foster attended CMAS 2014 workshop and conference One-on-one training for use of DAQ CMAQ system with Lance scheduled for early December 2014 December 15 2014. Complete testing of WRF sensitivity to land surface schemes (USGS, NLCD, MODIS) and snow cover options. On track to meet testing to 3 land surface schemes (see later slides). Timeline/Progress Update

5. Bigger Picture Timeline October 15 2014: Complete identification of possible prior winter case studies with DAQ staff; Case 1 choosen: PCAPS IOP5 (Jan 1-9 2011) Case 2 uncertain: PCAPS IOP1 (mix-out midway through episode?) November 15 2014: Graduate student attends CMAQ workshop to become familiar with atmospheric modeling needs required for CMAQ during late October. Chris Foster attended CMAS 2014 workshop and conference One-on-one training for use of DAQ CMAQ system with Lance scheduled for early December 2014 December 15 2014. Complete testing of WRF sensitivity to land surface schemes (USGS, NLCD, MODIS) and snow cover options. On track to meet testing to 3 land surface schemes (see later slides). March 15 2015. Complete testing of WRF sensitivity to PBL and cloud microphysics parameterization schemes April 15 2015. Assess whether any 2014-2015 air pollution events should be examined. July 15 2015. Complete testing of large-eddy simulations October 15 2015. Complete summary of types of cold air pools from modeling perspective and appropriate WRF model setup for the different types

6. USGS  higher albedo USGS  colder temps Recent Research: WRF CAP Sensitivity to Land Use 9 Day Average 2-m Temperature Difference USGS minus MODIS

7. Uinta Mountains Wasatch Range Tavaputs Desolation Canyon Plateau WY CO UT 1250 1500 1750 2250 2750 3250 3750 4000 3500 3000 2500 2000 Roosevelt Myton Ouray Horsepool Red Wash Vernal Recent Research: WRF CAP Sensitivity to Initialization Time Identical simulations started 1 day apart

8. Initialization 2 Initialization 1 31 December 20101 January 2011 2 January 2011 WRF CAP Sensitivity to Initialization Time Identical simulations started 1 day apart Obs 31 Dec 1 Jan Recent Research: WRF CAP Sensitivity to Initialization Time Identical simulations started 1 day apart 1 Jan

9. Past and Future Work: Improving WRF Snow Cover Parameterization -Idealized snow cover -Snow albedo changes -Edited VEGPARM.TBL Allows model to achieve high albedos measured in Uintah Basin 9 Snow Depth

10. Albedo Changes 10 OriginalModified 0.62- 0.65 0.81 - 0.82 -0.82 is average albedo measured at Horsepool during 2013 Uintah Basin Winter Ozone Study

11. Past and Future Work: WRF Cloud and Fog Modifications -Microphysics modifications (Thompson) in lowest 15 model layers (~500m): -Turned off cloud ice sedimentation -Turned off cloud ice autoconversion to snow  Results in ice-phase dominated low clouds/fog vs. liquid-phase Simulated Clouds Reality http://wwc.instacam.com/instacamimg/UBATC/UBATC _l.jpg Photo: Erik Crosman Cloud Ice Cloud Water Before After 11 Ice Fog

12. PBL: YSU ΔX = 1.33 kmLES: ΔX = 0.250 km 0 12 6 Wind Speed (m s -1 ) 2-m Temp (C) Great Salt Lake Salt Lake Valley Salt Lake Valley Great Salt Lake 3 9 10 0 5 -5 sltrib.com Toxic soup continues… Time to exercise!