# Presentation: 245496

## TES ozone profiles compared to ozonesondes

- ABSTRACT:   The Tropospheric Emission Spectrometer (TES) on the EOS-Aura spacecraft, launched July 15, 2004,  is making direct,  global observations of tropospheric ozone. Routine observations began in late August 2004. Ozone profiles are retrieved from TES infrared radiances with vertical resolution of roughly 6 km for nadir observations. The principal source of validation for TES O3 measurements is ozonesondes. For this analysis, we have focused on data from fall, 2004. In some cases, we have ozonesonde data from dedicated launches timed to match the Aura overpass, while other comparisons are performed with standard data available from the SHADOZ and WOUDC data archives. In order to make TES-ozonesonde comparisons, we must account for TES measurement sensitivity and the disparities in vertical resolution. This is done by applying the TES averaging kernel and constraint to the ozonesonde profile. Differences between TES profiles and the resulting (smoothed) sonde profiles are then compared to expected differences due to estimated retrieval errors, climatological variability and spatial/temporal  discrepancies. TES ozone profiles are systematically higher than sondes in the upper troposphere, but compare well in the lower troposphere. TES measurements are able to differentiate tropospheric ozone profiles over a range of (coarse) vertical structures.

- II. Comparison Examples

-  _http://tes.jpl.nasa.gov_

-  A41A-0010

- A41A-0010

- Trajectory analysis for comparisons with Boulder, Natal and Houston (AVE) sonde sites. Although some cases are inconclusive, differences > 5K in the temperature profiles generally indicate disparate trajectories and an unusable TES-sonde O3 comparison (not included in the statistics).

## III. Ensemble Comparisons 

- III. Ensemble Comparisons

- IV. Outlook & Conclusions

-  _http://tes.jpl.nasa.gov_

-  A41A-0010

_**Acknowledgements**_
- The work described here was performed at the Jet Propulsion Laboratory, California Institute of Technology and Harvard University, under contracts from the National Aeronautics and Space Administration.
- Thanks to Frank Schmidlan, Mike Newchurch and Gary Morris for dedicated sonde launches. Gary Morris of Valparaiso Univ. had sponsorship for AVE from the Shell Center for Sustainability and NASA's IONS program.
- The authors gratefully acknowledge the NOAA Air Resources Laboratory (ARL) for the provision of the HYSPLIT transport and dispersion model (http://www.arl.noaa.gov/ready/hysplit4.html) used in this presentation.

- _Improved L1B Calibration_
- (see poster: A41A-0007)
- Current L1B has differences with AIRS > 1K
- Improved L1B will be < 0.5K

- _Conclusions_
-  Comparisons to O3 sondes for current TES (v1, beta quality) data available at DAAC show:
-  TES is able to detect expected variability in the lower troposphere.
-  Bias in the upper troposphere is:
- 	- latitude dependent
- 	- peaked at 200 - 150 hPa
-  Comparisons for data with improved L1B calibration (only 3 cases available) show less bias in the upper troposphere.
-  Coincidence criteria are tricky for tropospheric comparisons but:
-  Using the TES-sonde tropospheric temperature differences as a filter seems to be a good proxy for trajectory analysis.
-  Will have more matches with denser nadir coverage
- (started in May 2005)

- TES Global Surveys with 2 vs. 3 nadir
- scans  per sequence