# Presentation: 395982

## TES and sonde O3 profile comparisons

- Helen Worden, Jet Propulsion Laboratory, California Institute of Technology
- Jennifer Logan, Harvard University
- TES Team

## PROCEDURE FOR COMPARISONS

- Apply averaging kernel, *A**TES*, and *a priori* constraint:

- _PROCEDURE FOR COMPARISONS_

## PROCEDURE (cont.)

- Measurement Error + Cross-State Errors

- _PROCEDURE (cont.)_

- O3 Sonde from Ascension Island
- 7.95°S, 14.37°W
- Launched 10/11/2004, 13:50 UTC
- Closest TES nadir measurement
- (Step/Stare run 2199):
- 7.756°S, 12.934°W
- (160 km away)
- DOFS: 3.7
- Vertical res: 6 to 9 km
- (avg = 7.2 km)
- in troposphere < 200 mb

## Fall 2004 TES-ozonesonde data coincidences

- SHADOZ, WOUDC data via Harvard and dedicated AVE launches (Houston)

## Sonde/Nadir Measurement

- Coincidence Criteria
-  Applied for fall 2004 (9/20 - 11/17) TES data
- both global survey & step/stare runs
-  SHADOZ & WOUDC data via Harvard +
- dedicated AVE launches (Houston)
-  Initial: 600 km, 48 hours (800 km for AVE), Chi2 < 2
- => 55 coincidences
-  More selective: Sonde-TES T_diff < 5K,  lat < 55°
- => 44 coincidences

## Trajectories for 11/17/2004,  Boulder

- Dist |Sonde-TES|:
- 193 km
- Time difference:
- 15 hrs

- Sonde vs. TES: Temperature          and                  Ozone

## Trajectories for 9/20/2004, Natal

- Dist |Sonde-TES|:
- 269 km
- Time difference:
- 1 hr

- Sonde vs. TES: Temperature          and                  Ozone

## Sonde (w/TES AK) - TES comparisons:

- Ozone and Temperature profiles

## Comparison of 3 sonde profiles (with TES AK) and 3 TES retrieved profiles - tropics

-       sonde		     TES retrieval	         initial guesss

## Comparison of 3 sonde profiles (with TES AK) and 3 TES retrieved profiles - sub-tropics/mid-latitude

-       sonde		     TES retrieval	         initial guess

## TES vs. sonde O3 averages for mid-lat & tropics

- Upper Trop
- (UT)
- 500mb>p>pTP

- Lower Trop
- (LT)
- p > 500mb

- 28 coincidences

- 16 coincidences

- __ 1 to 1

**Notes:**
Mid lat > 25deg

##  We have also looked at UT & LT differences vs:

- 	distance to sonde site (km)
- 	time (hrs)
- 	retrieval 2
- 	retrieved cloud top pressure
- 	avg. sonde vmr
-  Hard to see any definite trends...
-  Next: improved L1B calibration
-  >1K difference with AIRS is now <0.5 K
- (see TES Radiometric Assessment poster)

## comparison

- with current L1B

- comparison with
- L1B calfit prototype

- Payerne (47° N, 7° E)

- Temperature profiles (sonde vs. TES)

## Natal, Brazil (6° S, 35° W)

- Note improvement is mainly in the upper trop. as expected since lower radiances had the largest correction.

## L1B calfit prototype comparison 

- L1B calfit prototype comparison
- (troposphere, linear scale)

- Natal O3 sonde data for
- for Sep/Oct 2004

## Slide 16

## 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:
-  Cut on TES-sonde tropospheric temperature differences seems to be a pretty good proxy for trajectory analysis.
-  Will have more matches with denser nadir coverage
- (started in May 2005)

## Backup Slides

## Trajectories for 11/08/2004

- Sonde vs. TES: Temperature          and                  Ozone

- Dist |Sonde-TES|:
- 226 km
- Time difference:
- 21 hrs

- Backward trajectories to TES nadir measurement

## Trajectories for 10/31/2004 (AVE)

- Sonde vs. TES: Temperature          and                  Ozone

- Dist |Sonde-TES|:
- 580 km
- Time difference:
- 1hr

## TES Retrieval Error

- (Total Error Covariance)

- (Smoothing Error)

- (Cross-Term Error
- includes T, H2O for joint retrieval with O3)

- (Measurement Error)

- (Systematic Errors)

- Where **A** is the averaging kernel, **M** is a linear mapping matrix on pressure levels, **G **is the gain matrix and **K** is Jacobian matrix.

## Slide 22

## Sonde (w/TES AK) - TES comparisons:

- O3 relative and error weighted differences

## Differences vs. latitude & sonde O3 vmr averages

- Upper
- Trop
- (UT)

- Lower
- Trop
- (LT)

## Error weighted differences vs. distance & retrieval 2

- Upper
- Trop
- (UT)

- Lower
- Trop
- (LT)

## Sonde comparison

- with current L1B

- L1B calfit prototype
-  comparison

- Ascension Is. (8° S, 15° W)
- Also slight improvement in upper trop.

## L1B calfit prototype comparison 

- (troposphere, linear scale)

- Ascension O3 sonde data
- for Sep/Oct 2004

## Sonde comparison

- with current L1B

- L1B calfit prototype
-  comparison

- Payerne (47° N, 7° E)
- Note changes to lower O3 in upper trop. & lower strat

## TES Nadir Step & Stare Observations near Ascension Island

## TES Nadir Step & Stare Observations for 10/31/2004 (AVE)