Coupled NMM-CALMET Meteorology
Development for the CALPUFF Air
Dispersion Modelling in Complex Terrain
and Shoreline Settings
Presented at:
European Geoscience General Assembly
Vienna, Austria - April, 2011
Authors:
Zivorad Radonjic,* Dr. Douglas B. Chambers,
Bosko Telenta and Dr. Zavisa Janjic
* Contact: Zivorad Radonjic, zradonjic@senes.ca
Overview
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•
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•
•
•
•
•
•
Introduction
Study Background
Approach To Simulations
Approach To Validation
Comparison of WRF-NMM Model Versions 3.1.1
and 3.2.1
Effects of Horizontal Resolutions
Validation with Local Observations
One Year vs. Five Year Meteorological Datasets
Conclusions
Introduction
A study was undertaken to prepare and validate highresolution three-dimensional meteorology suitable for
use as input into the CALPUFF/CALMET air dispersion
model system in complex terrain with a shoreline.
The main goal was to demonstrate the good performance
of CALMET in a setting that involves both complex terrain
and a shoreline (land-water interface). Improvements in
CALMET performance possible using fine resolution
meso-scale model inputs were also demonstrated.
Study Background
• Meteorology required for
CALPUFF modelling of
industrial site in complex
terrain with shoreline
– A challenging meteorological
environment
• Site-specific meteorology
required for both long- and
short-range modelling
• No local observational data
available for time period in
question
Approach To Simulations
• Weather Research and
Forecasting - Nonhydrostatic
Mesoscale Model (WRF-NMM)
used as meso-scale model
• WRF-NMM modelled on 6 km
and 2 km horizontal resolution
• WRF-NMM used to initialize
CALMET modelled on 2 km and
250 m horizontal resolution
• 2009 meteorology modelled
Example Large Domain
(6 km x 6 km resolution)
for WRF-NMM Model
Example Small Domain
(2 km x 2 km resolution)
for WRF-NMM – CALMET
Model
Approach To Validation
• Simulations validated
by:
– Comparison of two versions
of WRF-NMM
– Comparison between models
run of different horizontal
resolutions
– Comparison of simulations
with observational data
• Wind Rose Comparisons
• Descriptive Statistics
• All validations at 10 agl
Select Meteorological Stations Used for
Model Validation
Comparison of WRF-NMM Model Versions
Wind Rose - Charlo Airport 2009
Wind Direction Frequency (%) (wind from)
• WRF-NMM Versions 3.1.1 and 3.2.1 compared
–
–
–
–
NNW
NW
N
32 NNE
28
NE
24
20
16
ENE
12
8
4
09-NMM-6km-V3.1.1
Versions yielded similar results WNW
2009
Good predictions of wind directionW
E
Wind speeds over-predicted dueWSW
to averaging / surface
09-NMM-6km-V3.2.1
ESE
SE predictions
Roughness over water causes higherSWwind speed
SSW
SSE
S
Wind Rose - Charlo Airport 2009
Wind Direction
Frequency
(%) (wind(%)
from)
Wind Direction
Frequency
NNW
NW
N
WNW
W
32 NNE
28
NE
24
20
16
ENE
12
8
4
09-NMM-6km-V3.1.1
ESE
09-NMM-6km-V3.2.1
E
WSW
SW
SSW
SE
SSE
S
Average Wind
SpeedWind
(m/s)Speed (m/s)
Average
NNW
NW
N
WNW
2009
8
6
4
2
NNE
NE
ENE
W
WSW
SW
SSW
S
09-NMM-6km-V3.1.1
E
2009
ESE
09-NMM-6km-V3.2.1
SE
SSE
Wind
Comparison
for Large WRF-NMM Domain (6 km resolution) - Charlo Airport
Average
WindRose
Speed
(m/s)
Note: Percentage of Calms: 2.22 %
NNW
NW
N
8
6
NNE
NE
Effects of Horizontal Resolutions - 1
Wind Rose - Gaspe Airport 2009
•
Wind Direction Frequency (%) (wind from)
Both WRF-NMM simulations over-predict wind speed
due to averaging /
N
NNW
NNE
under-prediction of surface roughness overNWwater /24
landNEinterface NMM-2.0km
20
–
•
•
16
12
8
4
Improved accuracy with finer (2 km) resolution
WNW
ENE
2009
WRF-NMM – CALMET simulation providesW better predictionE of wind speed due
2009-NMM-6.0km
to better representation of surface characteristics
and
vertical
resolution
WSW
ESE
CALMET-2.0km
No significant improvement in agreement with
wind direction
between the
SW
SE
SSW
SSE
S
three models.
Wind Rose - Gaspe Airport 2009
Wind Direction
Frequency
Wind Direction
Frequency
(%) (wind(%)
from)
NNW
NW
N
WNW
W
NNW
24 NNE
NE
20
16
12
8
4
E
2009
2009-NMM-6.0km
ESE
CALMET-2.0km
SW
SSW
SE
SSE
S
Average Wind Speed (m/s)
N
NW
NMM-2.0km
ENE
WSW
Average Wind
Speed
(m/s)
Average
Wind
Speed (m/s)
WNW
8
6
4
2
NNE
NE
09-NMM-2.0km
ENE
W
E
WSW
ESE
SW
2009
09-NMM-6.0km
CALMET-2.0km
SE
SSW
S
SSE
Wind Rose Comparison for Gaspe Airport
Note: Percentage of Calms: 15.58 %
NNW
N
8
NNE
Effects of Horizontal Resolutions - 2
• Wind speed predictions improve with finer resolution (250 m) WRFNMM- CALMET model
– Slight under-prediction versus over-prediction for other models
• No significant change in agreement with wind direction between the
four models.
Wind Direction Frequency (%)
Average Wind Speed (m/s)
Wind Rose Comparison for Bathurst Airport
Effects of Horizontal Resolutions - 3
Descriptive statistics used to evaluate simulation results
Wind Speed Summary Statistics – Bathurst Station
MODEL – Horizontal Resolution
WRF-NMM - 6 km
WRF-NMM - 2 km
WRF-NMM/CALMET - 2 km
WRF-NMM/CALMET - 250 m
Bias
0.92
0.82
-0.13
-0.09
MAE
1.73
1.72
1.34
1.31
RMSE
2.19
2.19
1.73
1.65
Q-Q Plot of Observed vs. Modelled Wind Speed – Bathurst Station
PerfectAgreement
Predictions (m/s)
•
15.0
Factor of Two
10.0
WRF-NMM-6 km
WRF-NMM-2 km
5.0
5.0
10.0
Observation (m/s)
15.0
CALMET-250 m
Effects of Horizontal Resolutions - 4
• Finer resolution improves:
– BIAS (average of all the differences between forecast and observation)
– Mean Average Error (the average magnitude of errors between forecast and
observation)
– Root Mean Square Error (measures the average magnitude of the error in a set of
forecasts, with increase weighting on larger errors)
• Descriptive statistics consistent with wind rose data
–
–
–
–
Over-prediction of wind speeds at larger horizontal resolutions
Good agreement of wind speeds at smaller horizontal resolutions
More accurate predictions with higher horizontal resolutions
WRF-NMM/CALMET on 250 m resolution most accurate simulation
Validation with Local Observations - 1
•
•
•
WRF-NMM/CALMET on 250 m horizontal resolution run for 2009
meteorology
Observations from local (2.5 km away) meteorological station available for
1999 to 2003
Good agreement noted between 2009 generated meteorology and
observational data
X - Site
X – Nearby Site
Wind Direction Frequency (%)
NNW
N
30
25
20
15
10
5
NNE
Site-2009 CALMET
Validation with Local Observations - 2
NW
WNW
NE
ENE
W
E
WSW
ESE
NearbySite9903
Observation
WIND ROSE
CALMET
Derived Site Wind Rose 2009 vs. Nearby Site 1999-2003 Observations
SW
SE
Site Wind Roses - 2009 vs. Nearby Site 1999-2003
SSW
Wind Direction Frequency (%)
Wind Direction Frequency (%)
NNW
N
NW
WNW
30
25
20
15
10
5
NNE
ENE
W
E
WSW
ESE
SW
NearbySite9903
Observation
SE
SSW
N
10
NW
WNW
NNE
NE
5
N
10
ENE
W
E
WSW
ESE
Site-2009 CALMET
NearbySite9903
Observation
(m/s)
NNE
NW
NE
5
WNW
ENE
W
E
WSW
ESE
SE
SSW
Average Wind Speed (km/h)
NNW
NNW
SW
SSE
S
Average
Wind
Average
Wind Speed
(km/h)Speed
Site-2009 CALMET
NE
SSE
S
S
SSE
Site-2009 CALMET
NearbySite9903
Observation
WIND ROSE
Site Wind Roses - CALMET (2009) vs. CALMET (2004-2008)
One Year vs. Five Year Meteorological Datasets
Wind Direction Frequency (%)
•
•
NNW
N
30 NNE
NE
WRF-NMM/CALMET on 250 m horizontal resolutionNW
run for 2009
compared
25 meteorology
Site-2009 20
CALMET
2004 to 2008 meteorology
15
WNW
ENE
10
CALMET
Differences between simulated meteorology for a 5-year period
are
5 and a 1-year period
W
E
(2004-2008)
to
inconsequential
WSW
ESE
For well simulated
data sets a single yearSW
of the derived three-dimensional
meteorology
WINDmeteorological
ROSE
SE
can,
for -most
purposes,
beCALMET
considered
to provide a reasonable
description
Site Wind
Roses
CALMET
(2009) vs.
(2004-2008)
SSW
SSE of on-site observations.
S
Average Wind Speed (km/h)
Wind Direction Frequency (%)
Wind Direction Frequency (%)
NNW
N
NW
WNW
30
25
20
15
10
5
NNW
NNE
NE
E
WSW
ESE
SW
SE
S
SSE
N
NNE
NE
5
WNW
CALMET
(2004-2008)
10
NW
Site-2009 CALMET
ENE
W
SSW
Average Wind Speed (m/s)
ENE
W
E
WSW
ESE
SW
Site-2009 CALMET
CALMET
(2004-2008)
SE
SSW
S
SSE
CALMET Derived Site Wind Rose 2009 vs. Nearby Site 1999-2003 Observations
Average Wind Speed (km/h)
NNW
NW
N
10
NNE
NE
Conclusions
1.
2.
3.
4.
Improvements in wind speeds predictions are achieved with use of finer
resolution meso-scale meteorological modelling in shoreline complex
terrain situations
Wind direction is not sensitive to effects of finer resolution modelling in
these situations
Coupled WRF-NMM/CALMET system provides a sound alternate to
costly and time consuming on-site data collection
One year of simulated meteorology corresponds closely to longer
periods of record and can used satisfactorily in environmental
assessments / air dispersion modelling if generated meteorology
sufficiently represents on-site observations.