Assessment of CO outflow during TRACE-P period

• Calculate CO distribution during TRACE-P period using University of Maryland CTM
• driven by fields from GEOS DAS (5 simulations)

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• Base: 2.0° x 2.5° grid / Monthly bb and Annual ff/bf (Kiley et al. based on Streets/Yevich/Logan)
• Bbb: 2.0° x 2.5° grid / Daily bb and Monthly ff/bf (Woo/Streets/Kiley)
• SGbb: “0.5 ° x 0.5°” / Daily bb and monthly ff/bf
• Boh: 2.0° x 2.5° grid / Monthly bb and Annual ff/bf / modified Spivakovsky OH (Russell Martin)
• BnC: 2.0° x 2.5° grid / Monthly bb and Annual ff/bf/ no deep convection

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• Compare with aircraft and MOPITT data. Optimize ff/bf and bb sources (minimizing RMS diffs between aircraft- and MOPITT-CO measurements. Evaluate resulting distributions.

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• Study in progress

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A-priori and a-posteriori correlation coefficients based on comparison of model output with 5-minute merge CO data from DC-8 Flights 7-17

Mid-Atlantic Air quality modeling efforts at the University of Maryland

Principals:

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Director: Russ Dickerson

CMAQ modeling: Jeff Stehr and Dale Allen

MM5: Da-Lin Zhang and Weizhong Zheng

SMOKE: Sheryl Ehrman and Yu-Jin Choi

GEOS-CHEM interface: Dale Allen and collaborators (planned)

Aircraft measurements: Bruce Doddridge, Lackson Marufu, and Brett Taubman

Funding: Maryland DOE, Maryland DNR, NARSTO-NE, MANE-VU, NE-OPS

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Purpose

• Scientifically-motivated and policy-driven simulations of Mid-Atlantic air quality

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• Past: Simulations of 1997 air quality with CMAQ driven by MM5. Default IC/BC
• Future: Simulations of 2002 (MDE’s choice) air quality with CMAQ driven by MM5. IC/BC from O₃ chemistry/PM version of GEOS-CHEM

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• Met fields for past and future simulations driven by MM5. “UMD”-MM5 includes PBL scheme (Zhang & Zheng) with an improved treatment of vertical mixing within very stable boundary layers.

CMAQ Options and Modules

• SMOKE Emissions, 1996 NET Inventory
• CB-4 Chemistry with MEBI Solver; AERO3 Aerosol Module
• No Plume-in-Grid
• July 5- July 21, 1997
• Horizontal grid: 12 km grid nested within 36 km grid
• Vertical grid: 24 MM5 layers collapsed to 16 CMAQ layers: Lowest 11 layers (3 km) unchanged
• Cloud: radm2
• June 2002 Release
• Sun Ultra-2

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Ozone Violations, July 12-17, 1997

UMd Research Aircraft

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GPS Position (°Lat, °Long)

Meteorology (T, RH, Pr, P_alt)

Carbon Monoxide (CO)

Ozone (O₃)

Sulfur Dioxide (SO₂)

Aerosol Optical Properties:

Absorption, B_ap (565 nm)

Scattering, B_scat (450,550,700 nm)

Particle Counts (CPC: TSI 3007)

Aerosol Particle Size (MetOne)

6 cuts: range 0.3–1.0μm

Aerosol Chemistry (PIXE Streaker)

*Aircraft operated by: University Research Foundation

1997 Flights

Bay Bridge

Fallston

Gaithersburg

Holbrook

Greene County

Gettysburg

AM Flight

PM Flight

Acknowledgements

• CMAQ modeling: Jeff Stehr and Russ Dickerson
• Aircraft measurements: Bruce Doddridge, Lackson Marufu, and Brett Taubman
• MM5: Da-Lin Zhang and Weizhong Zheng
• SMOKE: Yu-Jin Choi and Sheryl Ehrman

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• TRACE-P modeling: Kenneth Pickering, J. H. Woo, and Randall Martin
• Support: NASA Grants NASA.NAG59672 and NASA.NAG511246; Maryland DOEnvironment, Maryland DNR, NARSTO-NE, MANE-VU, NE-OPS