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)

Structure of talk

What is “WRF”, status of WRF/chem, near and not so near future

Evaluation: Comparison of WRF/chem and MM5/chem (MCCM)

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

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

                                                                                                           

WORKING GROUP 11: ATMOSPHERIC CHEMISTRY                                                                                                                       

Georg Grell (lead), NOAA/FSLPeter Hess (lead), NCAR

Carmen M. Benkovitz, Brookhaven National Lab

Daewon W. Byun, University of HoustonGreg Carmichael, University of Iowa

John McHenry, North Carolina

                                                                 

                    

Kenneth L. Schere, EPAPai-Yei, Whung, NOAAStu McKeen, NOAA/ALBill Skamarock NCAR

Rainer Schmitz, University of Chile and IMK-IFU

Doug Westphal (NRL)Jon Pleim, NOAA,ARL,EPA

Jerome Fast (PNNL)Jeff McQueen (NCEP/NWS)

MissionThe 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 GroupsThe 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/CHEMModel EvaluationFuture PlansReal-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

Registered WRF Users (10/9/02)

WRF Principal Partners 86

NCAR 38 NCEP 18 FSL 15 OU/CAPS 4 AFWA 11

U.S. Universities 169U.S. Government Labs 106Private Sector 94

Foreign 456 ----

Total 911

WRF Web site: http://wrf-model.org

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

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

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

Nonhydrostatic Model Solvers within WRF Common Infrastructure

WRF – Physics Options

MM5 – ETA – RUC ……. and more

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

“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.

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

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

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

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

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

Aerosol/radiation feedback through three variables

1. Dry scattering aerosol mass (organic and inorganic mass without soot)

2. Dry absorbing aerosol mass, soot only

3. Aerosol liquid water content

Absorption of (1) and (3) so far neglected. Scattering of (2) neglected

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

Physics and Chemistry Interface Design

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

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 ????

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

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

First version (chemistry) of WRF/CHEM = MM5/CHEM (MCCM)

Are results similar?

Validation in comparison with MM5/CHEM results from field

experiment

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)

Simulation Domains during July and August

D01– 110x135x35@

27 km horiz. res.– WRF/Chem and

MM5/Chem

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

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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

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

Online versus offline averaged concentration over half of the domain,

At 21Z

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