Status of the Development of a Tropospheric Ozone Product from

OMI Measurements

Jack Fishman1, Jerald R. Ziemke2,3, Sushil Chandra2,3, Amy E. Wozniak1,4,5 and John K. Creilson1,4

1NASA Langley Research Center

2NASA Goddard Space Flight Center

3Goddard Earth Science and Technology Center, University of Maryland Baltimore County

4SAIC International Inc.

5Also at NASA Goddard Space Flight Center

10th OMI Science Team MeetingKNMIDeBilt, Netherlands16 June 2005

Schematic Diagram Showing How TroposphericOzone Residual (TOR) is Derived

Tropopause(determined fromNCEP analysis)

~55 km

Surface

10-18 km

TOMS Total Ozone

~ 300 DU

Stratospheric OzoneProfile Derived fromSAGE or SBUV~ 270 DU

Calculate Tropospheric Residual 300 DU-270 DU

~ 30 DU

Separate Stratosphere from Troposphere to Compute Tropospheric Ozone Residual (TOR)

Heritage of Tropospheric Ozone from Satellites

Other Data Sets Are Required To Separate Tropospheric Ozone from

Total Ozone Measurements• Previous Studies• SAGE: Good Vertical Resolution; Poor Spatial Coverage• HALOE: Good Vertical Resolution; Poor Spatial Coverage• MLS: Vertical Resolution Only >68 mb; Relatively Good Spatial Coverage• Only One Archived Layer below 100 mb• SBUV: Poor Vertical Resolution; Good Spatial Coverage

Archived Layers: 1000–253 mb; 253-126 mb; 126-63 mb Stratospheric Fields Generated from 5 Days of Data

• Tropopause Heights: Archived Gridded Data Sets 2.5° x 2.5°

• For Aura Studies• HIRDLS: 4° latitude x 5° longitude• Tropopause Heights: Use Assimilated Data from DAO• Possible Use of OMI Vertical Profiles Averaged Over Each Orbit• Derive Tropospheric Ozone Using Convective Cloud Differential Methodology

From Original Proposal

SAGE/TOMS Tropospheric Ozone Residual (TOR) Seasonal Depictions

Dobson Units

Seasonal Depictions of Climatological Tropospheric Ozone Residual (TOR) 1979-2000

December - February

September - NovemberJune - August

March - May

Dobson Units (DU)

from Fishman, Wozniak, Creilson, Atmos. Chem. Phys., 3, 2003

Comparison of TOMS/SAGE TOR with TOMS/SBUV TOR: Regional Enhancements Not Previously Seen Now FoundRegional Enhancements Not Previously Seen Now Found

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Dobson Units (DU)

TOMS/SBUV TOR: June-July-August Climatology (1979-1991)

TOMS/SAGE TOR: June-July-August Climatology (1979-1991)

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Integrated Tropospheric Ozone (Dobson Units)

Tropospheric Ozone Residual (Jun-Aug Climatology)

Fishman et al. [2003, ACP, 3, 1453]

Measurement of Ozone Precursors such as Nitrogen Dioxide (NO2) on Aura will Provide Important Information that Should Lead to a New Understanding of the Origin and Distribution of Global Ozone (Smog) Pollution

Other Data Sets Are Required To Separate Tropospheric Ozone from

Total Ozone Measurements• Previous Studies

• SAGE: Good Vertical Resolution; Poor Spatial Coverage• HALOE: Good Vertical Resolution; Poor Spatial Coverage• MLS: Vertical Resolution Only >68 mb; Relatively Good Spatial Coverage• Only One Archived Layer below 100 mb• SBUV: Poor Vertical Resolution; Good Spatial Coverage

Archived Layers: 1000–253 mb; 253-126 mb; 126-63 mb Stratospheric Fields Generated from 5 Days of Data

• Tropopause Heights: Archived Gridded Data Sets 2.5° x 2.5°

• For Aura Studies• HIRDLS: 4° latitude x 5° longitude• Tropopause Heights: Use Assimilated Data from DAO• Possible Use of OMI Vertical Profiles Averaged Over Each Orbit

HIRDLS Daily Profile Coverage Will Provide Sufficient Information to Derive 3-Dimensional Stratospheric Ozone

Distribution Down to 1 km Below Tropopause

Current SBUV Daily Resolution

Other Data Sets Are Required To Separate Tropospheric Ozone from

Total Ozone Measurements• Previous Studies

• SAGE: Good Vertical Resolution; Poor Spatial Coverage• HALOE: Good Vertical Resolution; Poor Spatial Coverage• MLS: Vertical Resolution Only >68 mb; Relatively Good Spatial Coverage• Only One Archived Layer below 100 mb• SBUV: Poor Vertical Resolution; Good Spatial Coverage

Archived Layers: 1000–253 mb; 253-126 mb; 126-63 mb Stratospheric Fields Generated from 5 Days of Data

• Tropopause Heights: Archived Gridded Data Sets 2.5° x 2.5°

• For Aura Studies• HIRDLS: 4° latitude x 5° longitude HIRDLS Data Not Available: Using MLS Data• Tropopause Heights: Use Assimilated Data from DAO• Possible Use of OMI Vertical Profiles Averaged Over Each Orbit

Daily Product Derived from OMI/MLS(Plotted as average volume mixing ratio)

Monthly Product Derived from OMI/MLS(Plotted as average volume mixing ratio)

Other Data Sets Are Required To Separate Tropospheric Ozone from

Total Ozone Measurements• Previous Studies

• SAGE: Good Vertical Resolution; Poor Spatial Coverage• HALOE: Good Vertical Resolution; Poor Spatial Coverage• MLS: Vertical Resolution Only >68 mb; Relatively Good Spatial Coverage• Only One Archived Layer below 100 mb• SBUV: Poor Vertical Resolution; Good Spatial Coverage

Archived Layers: 1000–253 mb; 253-126 mb; 126-63 mb Stratospheric Fields Generated from 5 Days of Data

• Tropopause Heights: Archived Gridded Data Sets 2.5° x 2.5°

• For Aura Studies• HIRDLS: 4° latitude x 5° longitude HIRDLS Data Not Available: Using MLS Data• Tropopause Heights: Use Assimilated Data from DAO

Use Ozone from NOAA’s GFS (Global Forecast System) Model• Possible Use of OMI Vertical Profiles Averaged Over Each Orbit

GFS Model Run at t0-24 to Forecast Stratospheric

Column O3 for t0

Calculate TOR Product at t0

Isolate “Hot Spots” and Run Trajectory

Ensemble with NOAA’s HYSPLIT

Generate Guidance Product for t0+24Disseminate Guidance

Product to Air Quality Forecasters

Providing Guidance Products to Air Quality

Forecasters

SCO at t0-24 SCO at t0

TOR at t0

TOR at t0+24

OMI on Aura Total O3 from OMI

OMI Total Ozone

5-8 Nov 2004

GFS Model Output

SCO (100 -10 hPa)

4-8 Nov 2004

Calculated TOR4-8 Nov 2004

HYSPLIT Forward Trajectories Show High TOR on 6-7 November May Have Come from Fire Emissions Several Days Earlier

MODIS Aerosol 5 Nov

TOR - 6 Nov TOR - 7 Nov

Preliminary Results Encouraging! Much More Analysis Still Needed!

OMI/GFS TOR

OMI/MLS TOR

Comparison of TOR Products:

Weekly OMI/GFS TOR for March

Weekly OMI/GFS TOR for April

Weekly OMI/GFS TOR for May

Daily OMI/GFS TOR for May

Public Release GFS + Climatology Native GFS

Use of Complete GFS Product Should Improve TOR Current Calculations Use O3 from GFS 10hPa-100hPa

Other Data Sets Are Required To Separate Tropospheric Ozone from

Total Ozone Measurements• Previous Studies

• SAGE: Good Vertical Resolution; Poor Spatial Coverage• HALOE: Good Vertical Resolution; Poor Spatial Coverage• MLS: Vertical Resolution Only >68 mb; Relatively Good Spatial Coverage• Only One Archived Layer below 100 mb• SBUV: Poor Vertical Resolution; Good Spatial Coverage

Archived Layers: 1000–253 mb; 253-126 mb; 126-63 mb Stratospheric Fields Generated from 5 Days of Data

• Tropopause Heights: Archived Gridded Data Sets 2.5° x 2.5°

• For Aura Studies• HIRDLS: 4° latitude x 5° longitude HIRDLS Data Not Available: Using MLS Data• Tropopause Heights: Use Assimilated Data from DAO Using Information from NOAA’s GFS• Possible Use of OMI Vertical Profiles Averaged Over Each Orbit Not Tried Yet

Validation of Measurements Challenging

Stratospheric Column Ozone Derived from SBUV Agrees with SCO Derived from SAGE Profiles and with Available Ozonesonde Measurements:

•Proposed: HIRDLS to Provide Stratospheric O3 Profiles ~2 km resolution •Actual: Using MLS Data to Derive TOR•Challenge: Accuracy of Lower Stratospheric Data at Mid-latitudes

•Proposed: Use DAO to Provide Tropopause Heights

•Actual: Using GFS to Determine Stratospheric O3 and Tropopause Heights

• Challenges: GFS O3 not “user-friendly”

O3 calculated only from 100 hPa to 10 hPainitially using climatology to complete SCO

•Proposed: Use OMI Vertical Profiles to Calculate SCO•Actual: Have not tried to obtain OMI stratospheric profiles (availability?)

Study using SBUV shows good agreement with SAGE & O3sondes

•Proposed: Use Convective Cloud Differential Technique•Actual: Preliminary results

Tropospheric Ozone from OMI: Where are we?

Tropospheric Ozone from OMI Using CCD Method

Unforeseen Developments

• Use of Satellite Data to Calculate Tropospheric Data in Near-Real-TimeSuccessfully demonstrated for MODIS to calculate aerosol data

• Derivation of Tropospheric Ozone Directly from OMI Satellite Measurement

• Validation: Extremely Difficult for Troposphere

Direct Measurement of Tropospheric Ozone from GOME Recently Demonstrated

(Data Courtesy of K. Chance, SAO)

TOMS/SBUV TOR

Comparison of Tropospheric Ozone Derived Directly from GOME with TOMS/SBUV TOR

GOME(Data Courtesy of K. Chance, SAO)

Validation! Validation! Validation!Extremely Difficult for Troposphere

• Sensitivity of Backscatter Signal in Lower Troposphere

• Direct Underflights from Aircraft: Can never be completely synchronous

• Climatological Comparisons:How meaningful for near-real-time comparisons?

Comparison of TOR with O3 from UV-DIAL during TRACE-A Transit Flight

How do we validate TOR measurements?

One Last Thought:

• Patience!We’re still a long way from where we would like to be

• How good did TOMS data look in 1979?

• OMI data will evolve