WRF/Chem Regional WRF/Chem Regional Modeling of the Mid-Modeling of the Mid-Atlantic: Comparison Atlantic: Comparison with Aura and Ground with Aura and Ground Based MeasurementsBased MeasurementsElena Yegorova, Elena Yegorova, Dale AllenDale Allen, Christopher , Christopher Loughner, and Russell Dickerson of the Loughner, and Russell Dickerson of the

University of MarylandUniversity of Maryland

Kenneth Pickering of NASA-GSFCKenneth Pickering of NASA-GSFC

Goals of today’s talk Goals of today’s talk Analyze an east coast of the United States air Analyze an east coast of the United States air

pollution event using surface observations (AIRNOW pollution event using surface observations (AIRNOW 8-hr maximum ozone amounts), satellite retrievals 8-hr maximum ozone amounts), satellite retrievals from OMI and TES, and output from a regional from OMI and TES, and output from a regional atmospheric chemistry model. atmospheric chemistry model.

Obtain insight into the capabilities of OMI and TES to Obtain insight into the capabilities of OMI and TES to detect air pollution on the urban scale.detect air pollution on the urban scale.

What event? What event? July 9-11, 2007 pollution eventJuly 9-11, 2007 pollution event

What model?What model? On-line Weather Research and Forecasting model On-line Weather Research and Forecasting model

with integrated chemistry (WRF-Chem). with integrated chemistry (WRF-Chem).

Baltimore, MD visibility during a clear day

Baltimore, MD visibilityAt 6:45 PM July 9, 2007

Images obtained from the U.S. Air Quality Smog Blog (http://alg.umbc.edu/usaq).

Air quality on July 9, 2007 was Code Red (very bad) in the Mid-Atlantic. 8-hr max O3 of 131 ppbv within Baltimore NAA

Atmospheric Atmospheric ProcessesProcesses

WRF/ChemWRF/Chem

RadiationRadiation LW: RRTMLW: RRTMSW: GoddardSW: Goddard

Surface LayerSurface Layer Monin-Monin-ObukhovObukhov

Land Surface Land Surface ModelModel

NoahNoah

Boundary LayerBoundary Layer YSUYSU

CumulusCumulus GrellGrell

MicrophysicsMicrophysics Lin et al.Lin et al.

Gas-phase Gas-phase chemistrychemistry

RADM2RADM2

Aerosol Aerosol chemistrychemistry

MADE/MADE/SORGAMSORGAM

PhotolysisPhotolysis Fast JFast J

WRF/Chem ConfigurationWRF/Chem Configuration Domain: Eastern U.S. Domain: Eastern U.S.

12 km hor res, 23 vertical 12 km hor res, 23 vertical layerslayers

MOZART-4 chemical IC/BC MOZART-4 chemical IC/BC Meteorology driven by the North Meteorology driven by the North

American Regional Reanalysis American Regional Reanalysis (NARR) model with grid nudging (NARR) model with grid nudging (FDDA). (FDDA).

Emissions:Emissions: Points sources from July 2007 Points sources from July 2007

CEMS data. CEMS data. Area sources are projected Area sources are projected

2009 emissions used in SIP 2009 emissions used in SIP modeling. Grown from 2002 modeling. Grown from 2002 U.S. inventory.U.S. inventory.

Emissions processed using Emissions processed using SMOKE modeling systemSMOKE modeling system

M3DRY dry dep scheme M3DRY dry dep scheme implementedimplemented

No lightning NOx or No lightning NOx or stratospheric chemistrystratospheric chemistry

TES and OMI ProductsTES and OMI Products TES:TES:

Version 4 Level 2 Global Survey and Step & Version 4 Level 2 Global Survey and Step & Stare Special Observations (Nadir) Stare Special Observations (Nadir)

OMI/MLS global, daily tropospheric column OMI/MLS global, daily tropospheric column product: product: OMI total column minus stratospheric column OMI total column minus stratospheric column

from the Microwave Limb Sounder (MLS) from the Microwave Limb Sounder (MLS) (Lapse rate tropopause product of M.Schoeberl).(Lapse rate tropopause product of M.Schoeberl).

OMI Level-2 Ozone Profile Data, global, daily OMI Level-2 Ozone Profile Data, global, daily (Xiong Liu)(Xiong Liu)

Build-up to July 9, 2007 Air Pollution Build-up to July 9, 2007 Air Pollution Episode:Episode:

Comparison to ground stations Comparison to ground stations

WRF/Chem simulation: 00 UT July 6, 2007 – 00 UT July 12, 2007WRF/Chem simulation: 00 UT July 6, 2007 – 00 UT July 12, 2007 Good agreement along the I-95 corridor. Good agreement along the I-95 corridor. High-bias present over the Appalachian Range (northern GA to se VA) High-bias present over the Appalachian Range (northern GA to se VA) Note: After these simulations were made, a patch was added to M3DRY. This patch increasesNote: After these simulations were made, a patch was added to M3DRY. This patch increases deposition over water. deposition over water.

WRF/Chem and Beltsville, MD Ozonesonde WRF/Chem and Beltsville, MD Ozonesonde July 9,2007 18 UTC (1 pm EST)July 9,2007 18 UTC (1 pm EST)

Vertical Extent of July 9, 2007 Air Vertical Extent of July 9, 2007 Air Pollution EpisodePollution Episode

TES and OMI have the greatest sensitivity in the 850 TES and OMI have the greatest sensitivity in the 850 mb – 600 mb rangemb – 600 mb range

Capable of detecting pollution in the lower Capable of detecting pollution in the lower troposphere, but with greatly diminishing sensitivity troposphere, but with greatly diminishing sensitivity below 800 mbbelow 800 mb

TES OMI

TES and OMI TES and OMI Tropospheric Column Ozone – Tropospheric Column Ozone –

20070709 18UTC20070709 18UTC

TES measured elevated Tropospheric Column Ozone TES measured elevated Tropospheric Column Ozone (TCO) in the pollutant outflow region(TCO) in the pollutant outflow region

Origin of the Elevated Ozone Origin of the Elevated Ozone Air MassAir Mass

HYSPLIT 72 hr back trajectories from TES profiles with high HYSPLIT 72 hr back trajectories from TES profiles with high TCO values: starting at 2km (left), 4km (center), 7km (right)TCO values: starting at 2km (left), 4km (center), 7km (right)

At all levels air mass passed over the Great Lakes and Ohio At all levels air mass passed over the Great Lakes and Ohio River Valley within the previous 48 hours.River Valley within the previous 48 hours.

On July 7, 8, and 9, 2007 surface 8-hr max O3 was On July 7, 8, and 9, 2007 surface 8-hr max O3 was above 70 ppb in the Great Lakes Region and Ohio above 70 ppb in the Great Lakes Region and Ohio River Valley River Valley

How does TES-retrieved TOC How does TES-retrieved TOC during this event compare to during this event compare to

climatology? climatology? Analyzed TES TCO in the Analyzed TES TCO in the grid box [75W to 69W], grid box [75W to 69W], [30N to 38N] for:[30N to 38N] for: All 2005-2008 Step All 2005-2008 Step

and Stare and Stare ObservationsObservations

June-August 2005-June-August 2005-2008 Global 2008 Global Observations Observations

TES (Step and Stare) TCO TES (Step and Stare) TCO Climatology Climatology (2005-2008)(2005-2008)

TES measured TCO values ≥ 60 DU in the pollutant TES measured TCO values ≥ 60 DU in the pollutant outflow region are at the 95outflow region are at the 95thth percentile of all Special percentile of all Special Observation measurements made in July (2005-2008). Observation measurements made in July (2005-2008). Note: Note: Boxes show 25th and 75th%. Whiskers show 5th and 95th%.

Boxes show 25th and 75th%. Whiskers show 5th and 95th%.

TES (Global) TCO Climatology TES (Global) TCO Climatology (June, July, August 2005-2008)(June, July, August 2005-2008)

TES measured TCO values are ≥ 60 DU in the TES measured TCO values are ≥ 60 DU in the pollutant outflow region and are at ≈ the 75pollutant outflow region and are at ≈ the 75thth percentile of all Level 2 measurements made in June-percentile of all Level 2 measurements made in June-August (2005-2008).August (2005-2008).

TES, OMI, WRF/Chem (raw), TES, OMI, WRF/Chem (raw), MOZART-4 (raw) MOZART-4 (raw)

Tropospheric Column Ozone Tropospheric Column Ozone

TES, OMI, WRF/Chem, MOZART-4 TES, OMI, WRF/Chem, MOZART-4 Tropospheric Column Ozone Time series along TES Tropospheric Column Ozone Time series along TES

tracktrack

Results shown before applying TES and OMI averaging Results shown before applying TES and OMI averaging kernelskernels

TES measured the highest TCO values; OMI/MLS measured TES measured the highest TCO values; OMI/MLS measured the lowest TCO valuesthe lowest TCO values

TES WRF/Chem MOZART OMI/MLS OMI

AVG TCO (DU)

42.8 36.8 38.0 26.4 37.6

TCO

600 hPa < P < 800 hPa

ConclusionsConclusions Spatial pattern of July 9-11 air quality event is Spatial pattern of July 9-11 air quality event is

captured by WRF/Chem. captured by WRF/Chem. For this particular TES flight track, TES tropospheric For this particular TES flight track, TES tropospheric

OO33 column > WRF/Chem column; OMI >MOZART4 > column > WRF/Chem column; OMI >MOZART4 > OMI/MLS columnOMI/MLS column

Average TES bias: 8 DU for Tropospheric Column Average TES bias: 8 DU for Tropospheric Column OzoneOzone

TES detected elevated ozone off the coast, in TES detected elevated ozone off the coast, in agreement with WRF/Chem and MOZART-4 models, agreement with WRF/Chem and MOZART-4 models, illustrating continental outflow of pollution. Polluted illustrating continental outflow of pollution. Polluted air mass originated over Great Lakes and Ohio River air mass originated over Great Lakes and Ohio River Valley within previous 48 hours. Valley within previous 48 hours.

The high TES TCO values detected in this episode are The high TES TCO values detected in this episode are at the 75at the 75thth (95 (95thth) percentile of all July Global Survey ) percentile of all July Global Survey (Special Observations) data.(Special Observations) data.

*Acknowledgements: Gregory Osterman, Mark Schoeberl, Dylan Jones, George Grell, Steven Peckham, Xiong Liu, Louisa Emmons.

This study is a work in progress. This study is a work in progress. Possible next steps include: Possible next steps include:

Analyze sensitivity of results to domain through a Analyze sensitivity of results to domain through a nested 36/12 km simulation of event (TES retrieval on nested 36/12 km simulation of event (TES retrieval on edge of 12-km domain)edge of 12-km domain)

Investigate sensitivity of WRF-Chem calculated OInvestigate sensitivity of WRF-Chem calculated O33 to to convective parameterization, deposition module, convective parameterization, deposition module, chemical mechanism, and boundary conditions. chemical mechanism, and boundary conditions.

Compare WRF/Chem to Canadian flight data (Border Compare WRF/Chem to Canadian flight data (Border Air Quality and Meteorology Study [BAQMS]) on July Air Quality and Meteorology Study [BAQMS]) on July 8, 2008 around 8, 2008 around Lake St. ClairLake St. Clair

Compare WRF-calc and satellite-retrieved HCHO/NOCompare WRF-calc and satellite-retrieved HCHO/NO22 tropospheric column ratios for insight into chemical tropospheric column ratios for insight into chemical regimeregime

Compare WRF-calc PM2.5 to measurementsCompare WRF-calc PM2.5 to measurements Compare with additional TES retrievals. Compare with additional TES retrievals.