A next generation air quality prediction model and its real-time application at NOAA/FSL

1. A next generation air quality prediction model and its real-time application at NOAA/FSL Georg Grell Directly involved in WRF/CHEM development: Steven Peckham (NOAA/FSL), Rainer Schmitz (U. of Chile, IMK-IFU), and Stu McKeen (NOAA/AL) With WRF slides from: Bill Skamarock, John Michalakes, Joe Klemp (NCAR)

2. Structureof talk • What is “WRF”, status of WRF/chem, near and not so near future • Evaluation: Comparison of WRF/chem and MM5/chem (MCCM)

3. Weather Research and Forecast (WRF) Model Research: • Design priority for 1-10 km grids, but much larger applicability • Portable and efficient on many computer architectures • Advanced data assimilation and model physics • Well suited for a broad range of applications • Community model with direct path to operations

4. WRF Project Collaborators • Principal Partners: • NCAR Mesoscale and Microscale Meteorology Division • NOAA National Centers for Environmental Prediction • NOAA Forecast Systems Laboratory • OU Center for the Analysis and Prediction of Storms • Air Force Weather Agency • Federal Aviation Administration • Additional Collaborators: • NOAA Geophysical Fluid Dynamics Laboratory • NASA GSFC Atmospheric Sciences Division • NOAA National Severe Storms Laboratory • NRL Marine Meteorology Division • EPA Atmospheric Modeling Division • University Community

5. WORKING GROUP 11: ATMOSPHERIC CHEMISTRY Mission The mission of the atmospheric chemistry working group is to guide the development of the capability to simulate chemistry and aerosols — online as well as offline — within the WRF model.  The resulting WRF-chem model will have the option to simulate the coupling between dynamics, radiation and chemistry. Uses include forecasting chemical-weather, testing air pollution abatement strategies, planning and forecasting for field campaigns, analyzing measurements from field campaigns and the assimilation of satellite and in-situ chemical measurements. Interaction with other WRF Groups The initial development of WRF-chem is involved with the Numerics and Model Dynamics (WG1), Model Physics (WG11), and  Land Surface Modeling (WG14). Current Status of WRF/CHEM Model Evaluation Future Plans Real-time Air Quality Forecasts from WRF/CHEM This page developed by Bill Moninger and Randy Collander.Model questions should be directed to Georg Grell and Steve Peckham.Last modified: Thursday July 24, 2003 05:31:06 PM

6. Registered WRF Users (10/9/02) WRF Principal Partners 86 NCAR 38 NCEP 18 FSL 15 OU/CAPS 4 AFWA 11 U.S. Universities 169 U.S. Government Labs 106 Private Sector 94 Foreign 456 ---- Total 911 WRF Web site: http://wrf-model.org

7. Single version of code enabled for efficient execution on: Shared-memory multiprocessors Distributed-memory multiprocessors Distributed clusters of SMPs Vector and scalar processors WRF Multi-Layer Domain Decomposition Logical domain 1 Patch, divided into multiple tiles Inter-processor communication • Model domains are decomposed for parallelism on two-levels • Patch: section of model domain allocated to a distributed memory node • Tile: section of a patch allocated to a shared-memory processor within a node • Distributed memory parallelism is over patches; shared memory parallelism is over tiles within patches

8. Nonhydrostatic Model Solvers within WRF Common Infrastructure • Eulerian flux-form mass coordinate (official core) • Eulerian flux-form height coordinate • NMM model (NCEP core) • Semi-implicit, semi-Lagrangian core (future) • More possibly in future

9. WRF – Physics Options MM5 – ETA – RUC ……. and more

10. Every good modeling system needs a good analysis system: WRF 3DVAR

11. “Basic” WRF 3DVAR: Observations • Conventional: • Surface (SYNOP, METAR, SHIPS). • Upper air (radiosondes, pilot balloons, aircraft). • Remotely sensed retrievals: • Cloud-track winds (SATOBS). • ATOVS thicknesses (SATEMs). • Ground-based GPS TPW. • SSM/I oceanic surface wind speed and TPW. • SSM/T1 temperature retrievals. • SSM/T2 relative humidity retrievals. • Radiances: • SSM/I brightness temperatures. • Observation errors assumed uncorrelated.

12. WRF/chem (similar to MM5/chem also MCCM) • As of now: “Online”, sometimes also called “inline” • Completely embedded within WRF CI • Consistent: all transport done by meteorology model • Same vertical and horizontal coordinates (no horizontal and vertical interpolation) • Same physics parameterization for subgrid scale transport • No interpolation in time • Easy handling (Data management) • Most efficient (CPU costs) • Using massively parallel computers: efficiency will be even better for scenario calculations

13. Chemistry package • WRF grid-scale transport of all species (currently mass and scalar conserving 5th order in space, 3rd order in time) • 2 more advection schemes in preparation: Walczek and a version of ppm (both positive definite and more efficient, but less acurate • Subgrid-scale transport by turbulence • Subgrid-scale transport by convection

14. Current Chemistry Package • Dry deposition (coupled with soil/veg scheme, “flux-resistance” analogy) • Biogenic emissions (as in Simpson et al. 1995 and Guenther et al. 1994), includes emissions of isoprene, monoterpenes , and nitrogen emissions by soil) • Chemical mechanism from RADM2 (Quasi Steady State Approximation method with 22 diagnosed, 3 constant, and 38 predicted species is used for the numerical solution) • Photolysis (Madronich), being replaced with newer more efficient version, coupled with hydrometeors and aerosols

15. Aerosols • Based on Modal Aerosol Dynamics Model for Europe (MADE, Ackermann et al. 1998) • Modified to include Secondary Organic Aerosols (SOA), (Schell et al. 2001) • Extra transport: total number of aerosol particles within each mode as well as all primary and secondary species for Aitken as well as Accumulation mode • Diagnostic 3D variables: PM2.5, PM10, 3 variables for interaction with photolysis and atmospheric radiation

16. MADE/SORGAM • Modal representation: three modes (Aitken, Accumulation, Coarse), using log-normal distributions • Inorganic chemistry based on MARS (Saxena et al. 1986) • Organic chemistry based on SORGAM (Schell et al. 2001), anthropogenic and biogenic precursors are treated seperatly (for use with RADM2 chemistry biogenic precursors and their particle concentrations are set to zero • Dynamics include nucleation, condensational growth, and coagulation

17. Aerosol/radiation feedback through three variables • Dry scattering aerosol mass (organic and inorganic mass without soot) • Dry absorbing aerosol mass, soot only • Aerosol liquid water content Absorption of (1) and (3) so far neglected. Scattering of (2) neglected

18. Physics and Chemistry Interface Design • Flexible for use in different dynamical cores • Plug compatible - few places to modify if adding scheme • Model layer separated – no parallelization code in physics or chemistry

19. Additional development work in progress of interest to dispersion/air quality modeling • LES simulation tests for meteorological WRF at NCAR (50 - 100m resolution, Bill S.) • Choice of advection algorithms (Walczek, also an advanced version of PPM, Bill S.) • Use of NCEP’s NMM core • Preparation of direct comparison in real-time during next summer with CMAQ/ETA

20. In addition to main collaborators: Groups currently working with a version of WRF/chem • NCAR: Sasha Madronich • Daewon Byun from University of Houston • BAMS (McHenry and Coats) • PNNL • NCSU • ????

21. Who has voiced interest so far into taking part in further development in the NEAR future • NCAR (Peter Hess, Christine Wiedenmeyer, Sasha Madronich chemical mechanism, better photolysis (less expensive too!!), improved biogenic emissions, smoke from fires in real-time) • BAMS (John McHenry, Carly Coats, Implementation of SMOKE emissions module as well as work on aerosol module) • ARL/RTP/EPA (Jon Pleim and others, deposition, biogenic emissions, chemical mechanisms) • University of Houston (Daewon Byun) • AFWA (turbulence, fdda, biogenic emissions/luse/LSM coupling ) • DRI (Bill Stockwell, chemical mechanism) • PNNL (different aerosol approach, interaction with clouds/radiation, chemical mechanism) • NCSU (sectional aerosol approach) Many other groups have already voiced interest for the not so near future

22. Possible applications of current modeling system • Prediction and simulation of weather, or regional or local climate • Coupled weather prediction/dispersion model to simulate release and transport of constituents • Coupled weather/dispersion/air quality model with full interaction of chemical species with prediction of O3, UV radiation, as well as PM

23. First version (chemistry) of WRF/CHEM = MM5/CHEM (MCCM)Are results similar? Validation in comparison with MM5/CHEM results from field experiment

24. Real-time setup during Summer 2002(using MM5/chem) • MM5/chem (MCCM) was run in real-time twice a day from June through September 22 • Forecast length was 60 hours (12 hr FDDA + 48 hr forecast • 27 km horizontal resolution over central and eastern US • Model results were displayed on the Web, passed on to other Labs for verification • Ratio of wall clock/forecast time was 1:30 using 36 processors of FSL’s supercomputer (Linux PC’s)

25. Simulation Domains during July and August • D01 • 110x135x35@ 27 km horiz. res. • WRF/Chem and MM5/Chem

26. Use of data for evaluation and verification in real-time • ETL: meteorological data for verification with profiler data and surface obs: Displayed On Web (DOW) • AL: three-dimensional data set for verification with chemistry/met data, and forecasting aid for Ron Brown (NOAA’s vessel) DOW • ARL: Surface chemistry for verification • NSSL: common 3-d met data set for ensemble forecasting DOW

27. Verification with observations

28. Verification at ship vessel (Ron Brown)

30. Some online/offline comparisons • Same model: MM5/chem (MCCM), results with WRF/chem expected to be even more dramatic • No coordinate interpolations • Same physics • Horizontal resolution of 3km • Meteorological output at 1hr, ½ hour, 10 min, and every timestep for frequency analysis

31. E-W cross section of difference in ozone concentrations, online/offline, 1-hr 18Z

32. Online versus offline averaged concentration over half of the domain, At 21Z

33. WRF/chem – Current Work at NOAA • Completing verification with Summer of 2002 data (hopefully, after successful verification, put chemistry in WRF repository) • Running in real-time (same set-up as for 2002) • Our scientists will work with scientists around the country and the world to implement further improvements