1

Prepared by:Neil Wheeler, Steve Reid, and Ken Craig

Sonoma Technology, Inc.Petaluma, CA

Presented to:CCOS Technical Committee

Sacramento, CASeptember 14, 2006

905030

Progress Report on Improvement of Air Quality Model Aloft Performance

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Overview

• Proposed Phase 1 Improvements• Evaluation Process• Results• Modeling Domain Issue• Recommendations

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Proposed Phase 1 Improvements

• Meteorology (MM5)• Vertical Structure• Nighttime Mixing• Photolysis Rates• Wildfire Emissions• Anthropogenic and Biogenic Emissions • Emphasis on July-August 2000 Episode

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Evaluation Process

• Aloft Model Performance for Ozone• Hourly Averages for Grid Cells• Scatter Plots• Correlation

• Inert Tracer Simulations for Meteorology Changes

• Vis5D Animations of Ozone & Inert Tracers• Difference Plots• Ground Level Model Performance

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Model Performance Aloft

O3 Aloft ComparisonA53 vs. Observations

y = 0.3719x + 46.749R2 = 0.2956

0

50

100

150

200

250

0 50 100 150 200 250

Obs

A53P

red

O3 Aloft ComparisonTC vs. Observations

y = 0.3951x + 47.744R2 = 0.4367

0

50

100

150

200

250

0 50 100 150 200 250

Obs

TCPr

ed

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Results

• Completed• Meteorology (MM5)• Vertical Structure• Nighttime Mixing• Photolysis Rates

• In Progress• Wildfire Emissions• Emission Inventory Improvements

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Meteorology

• NOAA’s “Best” Simulation• Not our requested simulation

–No hourly average output–Interpolated observation FDDA

• Results• Not much change in performance or flow

structure• Vertically interpolated observation nudging

did not obscure or significantly weaken return flows

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Winds

Original New

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Vertical Structure

• CAMx and MM5 layers matched in first 2 km• 38 Layers• Results

• Better vertical resolution of winds in CAMx• Little change in net circulation

• Transport through boundaries aloft

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Ozonesondes

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Ozone Correlation by Level

0.0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1.0

3 4 5 6 7 8 9 10 11 12 17

CAMx layer

R-s

quar

ed

0.9 km

1.8 km7.5 km

0.25 km

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Ozone Transport Through Boundaries

1.3 km 5.0 km

Monday, July 31, 2000

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Nighttime Mixing

• Mechanical Mixing Model• Neutral and stable: van Ulden and Holtslag

(1985) • TKE profiles

• Near neutral : Zhang et al. (1996) • Stable: Lenschow et al. (1988)

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TKE Profiles

TKE (stable conditions)

0

50

100

150

200

250

300

350

0.000 0.500 1.000 1.500 2.000 2.500

TKE (m2/s2)

Heig

ht (m

)

TKE (neutral conditions)

0

50

100

150

200

250

300

350

0 0.5 1 1.5 2 2.5 3

TKE (m2/s2)

Hei

ght (

m)

TKE (unstablestable conditions)

0

50

100

150

200

250

300

350

TKE (m2/s2)H

eigh

t (m

)

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Nighttime Mixing Issues

• Surface roughness and friction velocity• Fire emissions• Recirculation

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Alternate Photolysis Rates

• Modified CAMx 4.31 to read in terrain elevations and calculate layer heights above mean sea level (MSL)

• April 2006 release of TUV 4.01 allows levels to be specified

• Pseudo-spherical two-stream delta-Eddington scheme

• Increased number of photolysis levels in CAMx from 11 to 27

Case photorig: Photolysis rates used in TC simulation

Case newphot: Terrain-corrected photolysis rates

Spatial Differences – New Photolysis

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MPE Aloft – New Photolysis

O3 Aloft ComparisonTC vs. Observations

y = 0.3951x + 47.744R2 = 0.4367

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50

100

150

200

250

0 50 100 150 200 250

Obs

TCPr

ed

O3 Aloft ComparisonNew Photolysis vs. Observations

y = 0.4098x + 46.243R2 = 0.4287

0

50

100

150

200

250

0 50 100 150 200 250

obs

PB

-new

phot

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Wildfire Emissions

• Smoldering emissions• First Order Fire Effects Model • Dominate VOC emissions from fires• Diurnal variations• Post burn smoldering• Issues with establishing defensible profiles

• Stack parameters and plume rise• Plume rise:

2 km (intended) vs. > 10 km calculated in CAMx• Default stack parameters: T=295 ˚K and V=4 m/s

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Wild Fire Tracers

16 km

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On-Road EI Improvements

• Heavy-duty diesel vehicle miles traveled (VMT) distributed based on vehicle activity rather than vehicle registrations

• Adjustments made to heavy-duty diesel emission factors• Modifications to the speed correction factors for heavy-

duty diesel vehicles• High idle emission rates for heavy-duty diesel vehicles

included• Diesel fuel correction factors incorporated• The impact of ethanol in gasoline on evaporative

emissions accounted for• Addition of areas into the Enhanced Smog Check program

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Off-Road EI Improvements

• Updates to equipment populations and activity data in the OFFROAD model (lawn and garden equipment, pleasure craft, etc.)

• Locomotive inventory updated to reflect growth from goods movement at ports

• Emissions from cargo handling equipment (CHE) at ports and rail yards estimated

• Moved to consistent statewide approach for estimating emissions from commercial marine vessels

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EI Improvements

• Biogenic Emissions• Acquired improved EI for Emissions

Reconciliation Project• Have not yet obtained or prepared model-

ready emissions and compared them to original model-ready emissions

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Modeling Domain

• Transport ozone and tracers out through southern and western boundaries

• SJVAQS 1990• Animations:

ftp://ftp.sonomatech.com/public/CCOS/CCOS-Animations.htm

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September 2000 Episode

• MM5 temperature bias• No new MM5 simulations• Biogenic emissions in southern SJV

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High Ozone Day TemperaturesEpisode2, PLR, Surface Gases

0

24

48

72

96

120

144

168

192

216

240

9/15

12:

00 A

M

9/15

12:

00 P

M

9/16

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9/16

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9/17

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9/17

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9/18

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9/18

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M

9/19

12:

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9/19

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9/20

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9/20

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M

9/21

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9/21

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9/22

12:

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9/22

12:

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M

9/23

12:

00 A

M

Date

O3,

NO

, NO

2 (p

pb)

0

1

2

3

4

5

6

7

8

9

10

CO

(ppm

)

O3NONO2NOYCO

Episode2, PLR (T), FAT (MH)

0

5

10

15

20

25

30

35

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45

50

9/15

12:

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9/16

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9/17

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9/17

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9/18

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9/18

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9/19

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9/19

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M

9/20

12:

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9/20

12:

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9/21

12:

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9/21

12:

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9/22

12:

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9/22

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9/23

12:

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Date

Deg

rees

(C)

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1800

2000

Mix

ing

Hei

ght (

m)

AMB

MH

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Maximum Predicted Temperatures

September 19, 2000

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Recommendations

• Correct stack parameters on wild fires• Implement new emission inventory• Nest CCOS domain within a larger

regional 12-km domain

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Questions?

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References

A.P. Van Ulden, A.A.M. Holstlag, Estimation of atmospheric boundary layer parameters for diffusion applications, J. Climate Appl. Meteor., 24:1196, 1985

Lenschow, D.H., X.S. Li, and C.J. Zhu, Stably stratified boundary layer over the Great Plains. Part I: Mean and turbulent structure, Bound.-Layer Meteor., 42, 95-121, 1988.

Zhang, C., D.A., Randall, C.-H., Moeng, M. Branson, M. Moyer, and Q. Wang, A surface parameterization based on vertically averaged turbulence kinetic energy, Mon. Wea. Rev., 124, 2521-2536, 1996.