Long Range Transport Mo

Evaluations 

Reassessment of Interagency 

Workgroup on Air Quality Modeling 

(IWAQM) Recommendations
Background

• 8th Modeling Conference – EPA recogniz

CALPUFF model science has evolved andiscusses intent to update Interagency Workgroup on Air Quality Modeling (IWAPhase 2 Guidance

– Formed CALPUFF Workgroup in 2005 to disc

issues and prioritize tasks

– Discussed need to perform updated model 

performance evaluation to examine new scieenhancements to model (e.g. puff splitting, Pturbulence, etc.) which are not reflected in cuguidance.
LRT Model Evaluation Pro

• EPA is performing five tasks for this project:

– Assemble a tracer and meteorological database f

with LRT model evaluations 

– Develop a comprehensive evaluation framework 

(methodologies and tools) for both meteorologica(prognostic and diagnostic) and LRT models for pof more scientifically robust and consistent evaluameteorological and LRT models

– Exercising and testing meteorological and LRT m

the assembled tracer database

– Provide full documentation of model evaluation m

and results from meteorological and LRT evaluat

– Updating existing EPA LRT modeling guidance (I

Phase 2) to reflect lessons learned from this proje
IWAQM Guidance Goal

• Examine science evolution of CALPUFF mode

system to incorporate recent enhancements to system in updated guidance. Overarching que

1. Can puff-splitting extend the effective range of 

CALPUFF beyond recommended distance of km?

2. Can guidance migrate to recommend turbulen

based dispersion (CALPUFF and AERMOD oover P-G?

3. How best to supply meteorological data to CA

(Best CALMET Options, MM5CALPUFF, etc.)
Mesoscale Tracer Experimen

• Great Plains Tracer Experiment (GP

1980 (currently evaluating)

• Savannah River Laboratory Tracer 

Experiment (SRL) – 1975 (underway

• Cross-Appalachian Tracer Experime

(CAPTEX) – 1983 (TBD)

• European Tracer Experiment (ETEX

1994 (completed)
Additional Tracer Studies to 

Included

• Project MOHAVE (Vimont, Koracin)• VTMX (Urban 2000) (?)• Dipole Pride 26 (Hanna & Chang)• Overland Along-Wind Dispersion (O

(Hanna & Chang)
Evaluation of Additional Mo

• Evaluation of additional modeling technology to 

understanding of additional LRT modeling and to a framework to understand how well can any moreasonably do with these experiments

– Lagrangian particle models (models routinely 

available with wide meteorological compatibi

• FLEXPART (Norwegian Institute for Air Re• HYSPLIT (Air Resources Laboratory, NOA

– Eulerian grid models

• Comprehensive Air Quality Model with Ext

(CAMx)
Evaluation Methods

• Irwin Method

– Plume arrival – Arc transit time– Fitted maximum– Observed maximum– Crosswind integrated 

concentration

– Plume sigma-y– Plume Azimuth

• ATMES-II statistical m

– Scatter

• Normalized Me

Error

• Factor of Exce• Factor of 2/5• Correlation

– Bias

• Fractional Bias• Mean Bias

– Spatial

• Figure of Merit • Probability of D• False Alarm R• Threat Score

– Cumulative distribu

• Kolomogorov-

Parameter

– Overall Model Ran
Great Plains Mesoscale Tracer Experi

• One of severa

EPA tracer stuCALPUFF, documented i454/R-98-009

• Two perflouro

tracer releaseNorman, OK and July 11, 1
Synoptic Meteorology – July 8-9, 
Model Experiment Desig

-500 -400 -300 -200 -100 0 100 200 300 400 500 600 700

-500-400-300-200-100

0

100200300400500

• Three Dispersion Mode1. CALPUFF:

– CALMET Meteorology

• Observation only• Hybrid (MM5 + Obs• NOOBS=1 (Obs su• NOOBS=2 (No Obs

MM5)

– MM5CALPUFF Meteorolo– All Dispersion Options

• P-G Turbulence• AERMOD Turbulen• CALPUFF Turbulen

– Puff-Splitting on 600 km s

100 km

– 100 km and 600 km arcs 

increments, 361 total rece

– 2 Domains: 100km, 600 k– 20 km CALMET for 60– 4 km CALMET for 100 

2. FLEXPART Lagrangian Pa3. HYSPLIT Lagrangian Parti

Model Receptor Arcs
MM5 Configuration

• MM5 Version 3.7.4 • 3 nested domains

– 108 km – 36 km– 12 km

• 34 vertical layers• ICBC: NCEP/NCAR 

Reanalysis Data available every 6 hours at 2.5° x 2.5°

• Physics:

– Kain-Fritsch II 

Cumulus

– ETA PBL – NOAH LSM– RRTM Radiat– Simple Ice 

Microphysics
Observed Maximum

P-G CALPUFF 

CALPUFF Dispersion O

Observe

d

Omax (ppt) – actual maximum

0.38 0.1561 0.1708 

Great Plains, July 8, 600 km, MM5 Winds

0.38 0.1647 0.1686 

Great Plains, July 8, 600 km

CALMET NOOBS=2 Winds

0.38 0.1593 0.1668 

Great Plains, July 8, 600 km

CALMET NOOBS=1 Winds

0.38 0.1489 0.1331 

Great Plains, July 8, 600 km

CALMET Hybrid Winds

0.38 0.867E-1 0.1543 

Great Plains, July 8, 600 km

CALMET Obs Only Winds

1.05 1.78 2.27 

Great Plains, July 8, 100 km, MM5 Winds**

1.05 2.362 1.946 

Great Plains, July 8, 100 km, CALMET** 

Winds

** Round 1 Results – will be updated
Plume Sigma-y

CALPUFF Dispersion 

Observe P-G CALPUFF 

d

19.5 43.85 35.42 

Great Plains, July 8, 600 km, MM5 Winds

19.5 48.66 27.92 

Great Plains, July 8, 600 km CALMET NOOBS=2 Winds

19.5 36.73 23.67 

Great Plains, July 8, 600 km CALMET NOOBS=1 Winds

19.5 52.9 35.18 

Great Plains, July 8, 600 km CALMET Hybrid Winds

19.5 52.2 30.91 

Great Plains, July 8, 600 km, CALMET Obs Only Winds

9.1 8.3 6.6 

Great Plains, July 8, 100 km, MM5 Winds

9.1 6.3 6.4 

Great Plains, July 8, 100 km, CALMET Winds

Cmax (ppt) – fitted maximum
Plume Arrival Time on A

Great Plains, July 8, 600 km, 191:0200 191:0200 191:0300 

MM5 Winds

Great Plains, July 8, 600 km 191:0200 191:0200 191:0200 

CALMET NOOBS=2 Winds

Great Plains, July 8, 600 km 191:0200 191:0100 191:0200 

CALMET NOOBS=1 Winds

Great Plains, July 8, 600 km 191:0200 191:0100 191:0200 

CALMET Hybrid Winds

Great Plains, July 8, 600 km 191:0200 191:0200 191:0100 

CALMET Obs Only Winds

Great Plains, July 8, 100 km, 190:1545 190:1700 190:1700 

MM5 Winds

Great Plains, July 8, 100 km, 190:1545 190:1600 190:1600 

CALMET Winds

Observed P-G CALPUFF 

Arrival Time at Arc CALPUFF Dispersion (Julian day: hour LST)
Arc Transit Time

P-G CALPUFF 

CALPUFF Dispersion Opti

Observed

Length of Plume Passage (hours)

Great Plains, July 8, 600 km, MM5 Winds 15 15 15 

Great Plains, July 8, 600 km 15

6

6

CALMET NOOBS=2 Winds

Great Plains, July 8, 600 km 15

6

6

CALMET NOOBS=1 Winds

Great Plains, July 8, 600 km 15

9

8

CALMET Hybrid Winds

Great Plains, July 8, 600 km 15

8

8

CALMET Obs Only Winds

Great Plains, July 8, 100 km,

5

4

4

MM5 Winds

Great Plains, July 8, 100 km, CALMET 

5

5

5

Winds
Plume Centerline

P-G CALPUFF 

CALPUFF Dispersion O

Observed

Plume Centerline (degrees from north)

9.8 17.9 17.44 

Great Plains, July 8, 600 km, MM5 Winds

9.8 20.15 28.01 

Great Plains, July 8, 600 km

CALMET NOOBS=2 Winds

9.8 25.03 25.01 

Great Plains, July 8, 600 km

CALMET NOOBS=1 Winds

9.8 25.91 26.52 

Great Plains, July 8, 600 km

CALMET Hybrid Winds

9.8 29.59 26.63 

Great Plains, July 8, 600 km

CALMET Obs Only Winds

1 -11.33 -8.78 

Great Plains, July 8, 100 km,

MM5 Winds

1 28.62 25.04 

Great Plains, July 8, 100 km, CALMET 

Winds
CALPUFF Simulations

OBS ONLY – AERMOD DISPERSION MM5 ONLY – AERMOD DISPERSION
European Tracer Experime

(ETEX)

• ETEX initiated in 1992 by 

European Commission (EInternational Atomic Ener(IAEA), and World MeteoOrganization (WMO) to aof the questions that aros1986 Chernobyl accident development of LRT mod

• ETEX was designed to va

range transport models uemergency response situdevelop a database whicused for model evaluation 

• Two releases of perflouro

tracer were made in OctoNovember 1994 from Fra

– The PFC was releas

constant rate for 12 h

– Air concentrations w

at 168 monitoring sitEuropean countries wsampling frequency ohours for approximat

A01

A02

A03

A04

A05

A06

A07

A08

B01

B02

B03 B04

B05

BG01

BG02

CH01 CH02

CH03

CH04

CR01

CR02

CR03

CR04

D01

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D46

D47

DK01

DK02

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DK06

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DK10

DK11

F01

F02

F03 F05 F04

F06 F07

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F23 F24

F25 F26

F27 H02 H01

H03

H04

N01

N02

N04

N05

N06

N07

NL01

NL02

NL03

NL04

NL05

NL06

NL07 NL08

NL09

PL01

PL02

PL03

PL04

PL05

PL06

PL07

PL08

R01

R02

S01

S02

S03

S04

S05

S06

S07S08

S09

S10

S11

S12

S13

S15 S14

S17 S16

S18

SF01

SF02

SR01

SR02

SR03

SR04

UK01

UK02

UK03

UK04

UK05

UK06

UK07
Experiment Design

• Meteorology

– MM5 Version 3.74

• Initialized with N

Reanalysis Data hourly at 2.5 x 2

• Kain-Fritsch II C• ETA PBL• NOAH LSM• RRTM Radiation

• LRT Models

– CALPUFF Version – HYSPLIT Version – FLEXPART Versio

(MM5)

• Each model coupled 

MM5 to facilitate betintercomparison
FLEXPART Time Serie

24 HR

48 HR
CALPUFF Time Series

00.010.020.050.10.20.5125102050

00.010.020.050.10.20.5125102050

24 HR 36 HR

48 HR 60 HR
HYSPLIT Time Series

0102050100200500100020005000100002000050000

0102050100200500100020005000100002000050000

24 HR 48 HR 
Spatial Statistics: ETEX

FLEXPART 30.07 0.27 0.54 HYSPLIT 41.4 0.55 0.36 CALPUFF 8.35 0.07 0.74 

T

False Alarm

Rate 

(FAR)

Probability of

Detection

(POD)

Figure of Merit

in Space

(FMS)

Statistical Measure

Model
Global Statistics: ETEX

RANK 0.66 1.78 KSP 79.00 39.00 FOEX -37.48 -10.65 -FA5 1.99 23.44 FA2 0.5 10.05 NMSE 202.12 18.12 1FB 1.27 0.69 PCC 0.02 0.32 Statistical CALPUFF HYSPLIT FLEMeasure
Initial Observations

• Insufficient number of tracer experiments to draw any c

from current data

• Great Plains Tracer Experiment

– CALPUFF/CALMET 100 km results performed well excep

azimuth. MM5 results better for azimuth, but worse for timand duration on 100 km arc.

• Unable to replicate 600 km arc statistics from original GP8

studies conducted by EPA in 1997 despite using same rameteorological data, horizontal, and vertical grid configura

• Two major differences from original EPA study are updated t

landuse from old CALPUFF 1.0 distribution and use of lambeprojection for GP80 and SRL, all other CALMET options remconstant. 

• CALPUFF performance varied due to variations in CALMET 

selected. CALPUFF results appear sensitive to manner in wmeteorology is supplied to the model.

• European Tracer Experiment

– CALPUFF performs reasonably compared to particle mod

24 hours, has more difficulty further into transport simulat

– Puff-splitting did not change CALPUFF performance signi

• Additional sensitivities for puff-splitting (eliminating mixing he

restrictions) increased number of puffs, but did not augment performance. 
Next Steps

• Project results shown today are work-inprogress

– Rebuilding database and simulation results a

critical hard drive failure in early summer

– Model evaluation protocol drafted – Full documentation and data availability nece– Need to engage with model developer to help 

understand some of our observations

• Did we go wrong in model setup? What can we do • Has the model changed since the previous evaluat