# Presentation: 814405

## Use of OMI Tropospheric Ozone Products for Air Quality Studies

- Jack Fishman1, Amy E. Wozniak1,2,3, John K. Creilson1,2
- James J. Szykman1,4
- 1Science Directorate
- NASA Langley Research Center
- Hampton, Virginia USA
- 2Also with SAIC International
- Hampton, Virginia USA
- 3Also with NASA Goddard Spaceflight Center
- Greenbelt, Maryland USA
- 4On Assignment from Office of Research and Development
- U.S. Environmental Protection Agency
- Research Triangle Park, North Carolina USA
- 							Aura Science Team Meeting
- 							The Hague, Netherlands
- 							November 8-10, 2005

## Maximize Information from OMI Total Ozone Data To Generate Tropospheric Ozone Product 

**Maximize Information from OMI Total Ozone Data To Generate Tropospheric Ozone Product **

**Challenge:****	****Separate Stratosphere Column Ozone ****	****	****from Total Ozone Signal**
- TOMS Heritage:
- 	• Collocated SAGE Ozone Profiles
- 	• SCO Field Generated from SBUV Ozone
- 	• Convective Cloud Differential
- 	• Scan-angle Dependence
- 	• Adjacent Altitude Differential
- 	• SCO from MLS
- Current Study:
- 	• Use OMI with Assimilation Model

## Schematic Diagram Showing How Tropospheric Ozone Residual (TOR) is Derived 

**Schematic Diagram Showing How Tropospheric Ozone Residual (TOR) is Derived **

- Tropopause:  Determined
- from NCEP or Model Analysis

- ~55 km

- Surface

- 10-18  km

**Total Ozone from Satellite**

- ~ 300 DU

- Stratospheric Ozone Profile Derived from Other Source

- ~ 270 DU

**Calculate Tropospheric Ozone Residual **

-  300 DU

- -

- 270 DU

- ~ 30 DU

## Stratospheric Column Ozone (SCO) Derived from SBUV and SAGE Profiles in Good Agreement

**Stratospheric Column Ozone (SCO) Derived from SBUV and SAGE Profiles in Good Agreement**

- Climatology from ~7000 SAGE profiles 1979-2000

- Climatology from ~800,000 SBUV profiles 1979-2000

- JJA Difference

- Very few regions where SCO differences are >5 DU

- from Wozniak et al. (2005, *JGR*, **110**, D20305)

## Comparison of TOMS/SAGE TOR with TOMS/SBUV TOR:  

- Regional Enhancements Identified Using More TOMS Measurements

- Dobson Units (DU)

- TOMS/SBUV TOR:  June-July-August Climatology

- TOMS/SAGE TOR:  June-July-August Climatology

**~8000 data points **
**5° x 10° grid**
**~10 data per box**

**~40,000,000 data **
**1° x 1.25° grid**
** ****~1400 data per box**

- from Fishman et al. (2003)

## Model-Derived SCO Provides Data Density Necessary to Construct TOR Fields from OMI Total Ozone 

**Model-Derived SCO Provides Data Density Necessary to Construct TOR Fields from OMI Total Ozone **

- • Filling data gaps between orbits requires sophisticated interpolation
- Or
- • Using measurements from additional orbits before or after day of OMI measurements

- • Use of data assimilation model provides ozone fields consistent with meteorological dynamics
- • Current generation of GFS model assimilates SBUV ozone
- • Additional satellite data will be assimilated into GFS model

## Comparison of GFS and MLS Stratospheric O3 Profiles

- Hohenpeissenberg

- Tateno

- Ascension Island

## Summary of Differences Between GFS and MLS SCO (10-100 hPa) Values

- _Station_		_MLS_	_GFS_	___DU___
- Ascension Island	149	155	  6 (4%)
- Boulder		122	131	  9 (7%)
- Hohenpeissenberg	112	123	 11 (10%)
- American Samoa	147	151	  4 (3%)
- Payerne		114	125	 11 (10%)
- Tateno		129	137	  8 (6%)
- Wallops Island	125	135	 10 (8%)
- 		

- • _Finding:_  GFS stratospheric values consistently higher than MLS values (4-11 DU or 3-10%)
- • Evaluation of MLS and GFS continuing exercise

## Major Advantage of GFS is Data Density Required for Smaller Scale Studies

## Daily TOR Maps from OMI May Provide Insight into Regional Scale Tropospheric Ozone Distribution

**Daily TOR Maps from OMI May Provide Insight into Regional Scale Tropospheric Ozone Distribution**

- U.S. Distribution (100 km resolution)

- Distribution over southeast Texas (~22 x ~30 km resolution)

**June 22, 2005**

## Accuracy of Regional TOR Dependent on Accuracy of OMI Total Ozone

- Stratospheric Gradient Minimal on Scales of Regional Interest

- • Stratospheric gradient over region of interest <5 DU
- • TOR Gradient over region of interest >20 DU must come from gradient in OMI total ozone column measurements

## Upward-Looking Ozone Column Measurements Confirm Small Stratospheric Gradient

**Upward-Looking Ozone Column Measurements Confirm Small Stratospheric Gradient**

- Flight path of WB-57

- Integrated O3 above aircraft along flight path

**Data from CAFS* Instrument**

***CCD (charged-coupled device) Actinic Flux Spectroradiometer**

## TOR Captures Mesoscale Ozone Structure in Houston Area

- 0-60 ppb
- 61-79 ppb
- 80-99 ppb
- 100-110 ppb
- 111-124 ppb
- 125+ ppb

*Rice University*
*G. Morris*

_**TOR Captures Mesoscale Ozone Structure in Houston Area**_

- Ozonesonde confirms elevated O3 in Houston on June 22, 2005

- TCO = 73 DU

## Where Do We Go From Here?

- • Continue evaluation of GFS SCO profiles
- 	- comparison with MLS
- 	- keep abreast of improvements to GFS
- • Continue validation studies with available ozonesonde and aircraft O3 data
- • Examine relationship between TOR patterns, synoptic conditions and surface O3
- • Work with air quality forecasters to see if OMI TOR product can provide useful information
- 	- CMAQ runs available during Texas-2005 campaign
- 	- joint proposals submitted with U.S. EPA and NOAA

_**Where Do We Go From Here?**_

## Next Steps:

- • Continue validation studies of TOR with available ozonesonde and aircraft O3 data

_**Next Steps:**_

## Next Steps:

_**Next Steps:**_

- • Examine relationship between TOR patterns, synoptic conditions and surface O3 (2005 active hurricane season)

- July 10

- July 11

## July 10

- July 11

- Tropical inflow

- Pollution outflow

- Inflow Regions Associated with Tropical Circulation and Continental Outflow Regions in Clear Air Behind Fronts Provide Examples that Can Relate TOR to Meteorology

## Clear Regions over Eastern U.S. Show High TOR 

- Clear Regions over Eastern U.S. Show High TOR

- June 22

- June 23

## Next Steps:

**Public **
**Impact**

**Scientific**
**Under-standing**

**   ****Global **
**  ****Assimilation**

**Regional**
**Prediction**

**Satellite Data**
**Products**

_**Next Steps:**_
- • Work with air quality forecasters to see if OMI TOR product can provide useful information

## Next Steps (Summary)

- • Continue evaluation of GFS SCO profiles
- 	- comparison with MLS
- 	- keep abreast of improvements to GFS
- • Continue validation studies with available ozonesonde and aircraft O3 data
- • Examine relationship between TOR patterns, synoptic conditions and surface O3
- • Work with air quality forecasters to see if OMI TOR product can provide useful information
- 	- CMAQ runs available during Texas-2005 campaign
- 	- joint proposals submitted with U.S. EPA and NOAA

## Summary and Conclusions

- • New method to derive TOR using OMI in conjunction with GFS-derived SCO fields
- • Initial comparisons of GFS stratospheric O3 and MLS O3 profiles encouraging
- • High spatial resolution TOR derived from OMI seems to be able to capture sub-regional scale pollution pattern around Houston area for a specific time
- 	- surface O3 and aircraft measurements support TOR analysis