Puff vs. Plume

A preliminary consideration on the advantages of puff models over plume modelsshould be based on the following modeling requirements:

Whether the straight-line steady-state assumptions on which a plumemodel is based are validTransport distancesPotential for temporally and/orspatially varying flow fields due toinfluences of complex terrainNon-uniform land use patternsCoastal effectsCalm winds and stagnation conditionsVariable wind directions

For cases involving a high degree ofspatial variability of the flow within theboundary layer, such as up-slope ordown-slope flows or flows along awinding river valley, the straight-linesteady state assumption may not bevalid beyond even a few kilometers, anda puff model may be more appropriate.

Different than a plume model, a puff model releases emissions independent of thesource, allowing the puff to respond to the meteorology immediately surrounding it.This also allows puffs to be tracked across multiple sampling periods until it has eithercompletely diluted or has tracked across the entire modeling domain and out of thecomputational area.

Simulates pollutant releases as a continuous series of puffs

Model Descriptions

CALPUFF

A Transport and Dispersion Model

CALPUFF is a non-steady-stateLagrangian Gaussian puff modelwhich builds on the CALMET griddedwind field, and contains modules forcomplex terrain, overwater transportand coastal interaction effects,building downwash, wet scavenging,dry deposition, and simple chemicaltransformation.

CALMET

A Diagnostic 3-D MeteorologicalModel

CALMET is a meteorological modelwhich includes a diagnostic wind fieldgenerator containing objectiveanalysis and parameterizedtreatments of slope flows, kinematicterrain effects, terrain blockingeffects, a divergence minimizationprocedure, and a micro-meteorological model for overlandand overwater boundary layers.

CALPOST

A Post-Processing Program

CALPOST is a post-processingprogram with options for thecomputation of time-averagedconcentrations and deposition fluxespredicted by the CALPUFF model.CALPOST computes visibility impactsin accordance with IWAQM and FLAGrecommendations. CALPOST requiresonly the CALPUFF outputs, althoughthe final visualization often requiresmultiple additional programs.

Puff Plume

Wind

Hour 1 Hour 10 Hour 25 Hour 35 Hour 45 Hour 55

A schematic depicting the tracking differencesof a puff and a plume model

www.weblakes.com | Phone: (519) 746-5995 | Fax: (519) 746-0793 2

CALPUFF View is an unparalleled GIS-based interface for the U.S. EPAapproved CALPUFF modeling system.CALPUFF View provides a completegraphical solution to CALPUFF, CALMETand CALPOST modeling, supporting allpre- and post-processing of projectdata, powerful and independent QAtools, and stunning report-ready results.

cat_apr2006_final.qxd 26/04/2006 8:40 PM Page 3

Visibility Analysis & Post-Processing

CALPOST computes visibility impacts inaccordance with IWAQM and FLAGrecommendations.

With the seamless integration ofthis powerful post-processor,model results of concentration,dry deposition, and wetdeposition can be plotted withease. The integrated contouringtools provide all the visualizationeffects of the most sophisticatedGIS package, eliminatingcomplicated exporting.

3-D Diagnostic Meteorological Model

Integrated prognostic model support (MM5/MM4 and CSUMM output)Streamline input & processing of hourly surface and precipitation observations,twice-daily upper air soundings, overwater stations, and gridded surfacecharacteristics.

Recommended by the U.S. EPA

Some examples of applications for which CALPUFF may be suitable include:

Near-field impacts in complex flow or dispersion situations complex terrain stagnation, inversion, recirculation, and fumigation conditions overwater transport and coastal conditions light wind speed and calm wind conditions

Long range transport Visibility assessments and Class I area impact studies Criteria pollutant modeling, including application to State Implementation Plan (SIP)development Secondary pollutant formation and particulate matter modeling Buoyant area and line sources (e.g., forest fires and aluminium reduction facilities)

CALPUFF View facilitates the entry of detailed information regarding source geometry,spatial and temporal variability of emission sources, additional sub-grid definition, ozonemonitoring, chemical transformation, and depositional velocity data for each speciesmodeled.

3D Visualization

Giving you total control, you can zoom inand rotate your site and modeling resultsin true 3-dimensional space. This allowsyou to view your model from anyperspective and further investigate whatis influencing your model results!

Complete 3D visualization Seamless 2D to 3D 3D wind fieldsMulti-layer visualization Realistic views Concentration contours 3D animations

Seamless 2D to 3D

Graphical Options

Multimedia Options

www.weblakes.com | Phone: (519) 746-5995 | Fax: (519) 746-07933

cat_apr2006_final.qxd 26/04/2006 8:41 PM Page 4

Graphical Tools

Graphical tools allow you to rapidly create your model whilegenerating dynamic visualization.

DEM Converter

Easily create USGS 7.5minDEM files from differentterrain elevation formats:

CDED 1-degreeU.K. NTFU.K. DTMXYZ FilesGTOPO30 DEMAutoCAD DXF

Coordinate Converter

Typically modeling mustbe done using a fixedlength unit (i.e. meters).The length of eachdegree varies withlatitude, and sogeographic coordinatesmust be converted fromlat/long to meters. Thecoordinate converterincluded with CALPUFFView supports UTM &Lambert Conic Conformalprojections and fivedatums:

WGS-84NAD-27NWS-84NWS-27ESRI Ref Sphere

Land User Creator

Finding accurate surfacedata for your CALPUFFprojects can be difficult.CALPUFF View includes aLand Use Creator toolwhere you can digitizeon-screen directly fromany available base map(Bitmap, Shapefile,Mr.SID, etc.)

Code each cell using theUSGS Land UseClassification Codes.Save in CTG format fordirect importation intoyour CALPUFF Viewproject.

CALPUFF View users have access to additional met data for USA, Canada & Mexico. FREE !

Features

Calm wind algorithmsSub-grid boundary layer calculationsVertical wind shearSub-grid complex terrainBuilding downwash & BPIP interfaceOverwater & coastal interaction effectsChemical transformation options

MESOPUFF IIRIVAD/ARM3

ISCST3 or AERMOD project conversionSlope flow & kinematic terrain effectsStagnation, inversion, recirculation and fumigationconditionsCriteria pollutant modelingSecondary pollutant formation and particulate modelingNon-steady-state emissions and meteorological conditionsAutomatic downloading of terrain and met data

Spatial Data

Land Use Creator

Coordinate Converter

DEMs

A

Annotation Toolbar

Application Toolbar

Point SourceArea SourceVolume SourceLine SourceMet GridComputation GridSampling GridDiscrete ReceptorRing ReceptorsPolygon DiscreteCircular BuildingRectangular BuildingPolygonal BuildingShow/Hide SIZShow/Hide GEPCoastal LinesBarriersLake BreezeCTSG Receptor

www.weblakes.com | Phone: (519) 746-5995 | Fax: (519) 746-0793 4

Select Zoom InZoom OutPanMin. ExtentsMax. ExtentsDeleteRectangle Circle Polygon Text Marker Arrow North Arrow Overlay MeasureMap ImportSite DomainOptionsIdentify

cat_apr2006_final.qxd 26/04/2006 8:41 PM Page 5