CANSAC MECHANICS

Julide Kahyaoglu-Koracin

CANSAC Workshop

16 February 2006Sacramento, CA

CANSAC Operations• Program for Climate

Ecosystem and Fire Applications (CEFA) at Desert Research Institute (DRI) in Reno, NV, facilitates the operational component of CANSAC.

• Operational functions of the center can be viewed under two groups:– Realtime numerical weather predictions.

– Air quality and fire danger assessment forecasts.

Hardware Base

• SGI Altix 3700, Linux OS

• 32 Itanium processors each at 1.3 GHz

• 80 GB RAM

• 2x1.3 TB Raid

• 4TB Tape drive (~.5TB monthly data archive)

• Intel Fortran compilers

Numerical Weather Predictions • The Fifth Generation

Penn Sate/NCAR Mesoscale Model (MM5) is used as the realtime numerical model.

• It is a community model that can be applied to realtime and historical studies of a large spectrum of weather events: mainly mesoscale convective systems, fronts, land-sea breeze and mountain-valley circulations.

Physics Options in MM5: cumulus parameterization

• 1. None – grid sizes < 5-10 km.• 2. Anthes-Kuo -

based on moisture convergence (larger grid sizes > 30 km).• 3. Grell -

based on rate of destabilization or quasi-equilibrium, simple single-cloud scheme (smaller grid sizes 10-30 km)

• 4. Arakawa-Schubert -multi-cloud scheme similar to Grell scheme (larger scales > 30 km).

• 5. Fritsch-Chappell -based on relaxation to a profile due to updraft, downdraft and subsidence region properties (20-30 km scales)

• 6. Kain-Fritsch -similar to Fritsch-Chappell, but using a sophisticated cloud-mixing scheme to determine entrainment/detrainment.

• 7. Betts-Miller -based on relaxation adjustment to a reference post-convective thermodynamic profile over a given period (scales > 30 km).

1. Bulk PBL - suitable for coarse vertical resolution in boundary layer, e.g. > 250 m vertical grid sizes. Two stability regimes.

2. High-resolution Blackadar PBL -suitable for high resolution PBL, four stability regimes, including free convective mixed layer.

3. Burk-Thompson PBL -predicts turbulence kinetic energy for use in vertical mixing, based on Mellor-Yamada formulas.

4. Eta PBL -the Mellor-Yamada scheme as used in the Eta model. It predicts TKE and has local vertical mixing.

5. MRF PBL -or Hong-Pan PBL, suitable for high-resolution in PBL (as for Blackadar scheme). Efficient scheme based on Troen-Mahrt representation of countergradient term and K profile in the well mixed PBL.

6. Gayno-Seaman PBL -this is also based on Mellor-Yamada TKE prediction. It is distinguished from others by the use of liquid-water potential temperature as a conserved variable.

Physics Options in MM5: PBL schemes

Physics Options in MM5 (cont.)• Explicit moisture schemes:

– 8 schemes including warm rain, simple ice, and mixed phase (Dudia)

• Radiation schemes:– None, simple cooling, surface radiation,cloud radiation, CCM2, RRTM.

• Surface schemes:– None, Blackadar schemes, Five-Layer Soil model, Noah Land-Surface model, Phleim-Xiu Land-Surface Model

CANSAC MM5 Configuration• Coarsest domain 36 km, nested

domain 12 km, and innermost (Nevada/California) domain 4 km horizontal grid spacing and 32 sigma (vertical) levels.

• Physics: – PBL scheme: ETA – Cumulus: Grell– Moisture: Simple ice– Radiation: cloud– Soil: Five-Layer soil model

• Initialized with ETA forecasts (40 km - Grid212)

• LDM Unidata observations:– SYNOP– AIREP– METAR– SHIPS– PILOT

• Initialized at 00Z and 12Z• Forecast length: 72 hr for domains

1 and 2, and 60 hr for domain 3

CANSAC BlueSky SystemFire Characteristics

Area burned

Fuel moisture

Fuel loadings

Fire location

Fire ignition time

Meteorology

CANSAC MM5 outputs

Winds/Temps/Moisture

12 and 4 km domains

72 and 60 hour (-12 hr spin up) forecast

Emissions

EPM emissions model

Fuel consumption

Variable rate emissions

PM10, PM2.5,CO, CO2, CH4

Smoke Dispersion&Transport

CALPUFF/CALMET modeling system

PM2.5 concentrations

Display

PAVE visualization package

NCL images (in progress)

Loops and hourly concentrations of PM2.5

Emissions

• Emissions are computed using Consume/EPM v1.03 which calculates the heat release rate and emissions for particulate matter and carbon compounds as a function of time since fire ignition.

• Fuel characteristics input this model are derived from the Fuel Characteristic Classification System (FCCS).

CALPUFF/CALMET DISPERSION MODELLING SYSTEM

• CALPUFF is a multi-layer, multi-species non-steady state Lagrangian puff dispersion model which can simulate the time and space varying pollutant transport, transformation and removal.

• It contains algorithms to account for – Dispersion– Plume rise– Building downwash– Partial plume penetration– Overwater and coastal dispersion– Complex terrain– Dry deposition– Chemical transformation– Wet removal– Odor and visibility modeling.

CALPUFF/CALMET • CALMET is a diagnostic meteorological model which

calculates the three dimensional winds and temperatures along with microphysical parameters such as surface characteristics, dispersion parameters, and mixing heights to be used by CALPUFF dispersion model.

• It can also incorporate the output of prognostic weather models such as MM5. In this case, prognostic fields can be used as initial fields, step 1, or the observations.– BlueSky forecasts use MM5 outputs as the pure observations/objective analysis in CALMET.

• Wind fields processing includes kinematic effects of terrain, slope flows, blocking effects, divergence minimization.

CALPUFF/CALMET • Dispersion

– Pollutant puffs travel along a Lagrangian trajectory and are sampled at every receptor. Each puff is treated as Gausian plume. Dispersion coefficients are calculated based on observations, PG stability classes, or computed internally.

• Puff splitting– Puff splitting is considered due to vertical wind shear.

• Puff stretching (horizontal convergence)• Plume rise

– Plume buoyancy, atmospheric strafication, partial plume penetration into a stable layer, area source plume rise (parameters passed from EPM for fire sources), line source plume rise (Briggs (1975) equations).

BlueSky Runs

• Currently the system runs using WILDFIRE209 reports.

• These reports are received daily around midnight.

• The model run starts after the burn data download.

• 60 and 48 hour forecasts for 12 and 4 km domains, respectively.

Forecast Verification

• Temperatures can be uneresdtimated up to 5˚C.

• Implications: soundings, stability, PBL depth, diagnostic parameters such as air quality and fire danger indices, etc…..

ETA modelInitial hoursurface

temperature&

winds

MM5 surfacetemperatureand windsfor the

correspondinghour

Forecast Verification: case study 20 July 2005

• Extreme surface temperatures and deep atmospheric layers during a period of 14-20 July 2005 (Lewis et al., 2005).

• Despite the increased temperatures, pollution concentrations were low and diluted.

• Low Haines index predictions.

Forecast Verification: case study 20 July 2005

• ETA PBL• RRTM• Five-layer LSM• Simple-ice

• ETA PBL• RRTM• Noah LSM• Reisner 2

• Gayno Seaman PBL

• RRTM

• Five-layer

LSM

• Simple-ice

• MRF PBL• RRTM

• Five-Layer LSM

• Simple-ice

Forecast Verification: case study 20 July 2005

Future Products….

• Cross section plots – Redding– Sacramento– San Francisco– Los Angeles– Bakersfield– Fresno

Future Products (cont.)

• 3K ft - ground level temperature difference.

Future Products (cont.)

• Time-height plots at the current selected CANSAC point locations (RAWS).

• Point verifications.

Future Products (cont.)

User Requests !!!!