# Presentation: 805602

## Summary of subgroup results for Stratospheric Ozone Validation

- Ray H.J. Wang

- AURA Science Meeting, Boulder, September 11-15, 2006

## HIRDLS

-  Bruno Nardi
- MLS
-  Lucien Froidevaux (Strat. (and mes.))
-  Yibo Jiang et al. (LS/UT )
- Aura/airborne ozone instruments comparisons
-  Irena Petropavlovskikh
-  Michael Coffey

## Ozone Observations aboard the DC-8

- Insitu O3		NASA  LaRC	        Avery                        O3
- LIDAR		NASA  LaRC	        Browell                     DI
- IR abs FTS		NCAR                     Coffey	       	      IR
- LIDAR		NASA  GSFC          McGee	       	      AR
- Sub-mm emiss spect.	U. of Bremen	        Notholt	                  AS
- Actinic flux spect.	CU/NCAR	        Petropavlovskikh      PO

- (during PAVE in Jan.-Feb., 2005)

- Coffey et al.

## Coffey et al.

- Feb. 5

- Feb. 7

**OMI**
**MLS**
**HIRDLS**
**NCAR FTS**

-                 Lon.

-                 Lon.

- -90

- -70

- 70

- 40

- Lat.

## MLS/CAFS summary, Jan 2006

- Stratospheric column ozone comparisons  (Petropavlovskikh et al)

## Conclusions

- CAFS continues to provide reference for stratospheric ozone column products (MLS, OMI/SBUV) with better than 2 % accuracy.
- Summary of CAFS error is complete and available upon the request.

- (Petropavlovskikh et al)

## HIRDLS-ACE/FTS Ozone Differences

_**HIRDLS-ACE/FTS Ozone Differences**_

**Thick red:**** **
**   ****Average**
**Dotted red:**
**   ****1-****σ**** distribution **
**Thin red:**
**   ****1-****σ**** uncertainty**
**    ****(often hidden)**
**Black points:**
**   ****Individual**
**   ****differences**

- 09/2006, v2.02
- Data: May 2006

**Cora Randall,  ACE Team: P. Bernath, C. Boone, S. Mcloed**

## 09/2006, v2.02.02

**Ozonesonde Comparisons with HIRDLS****Statistical Summary: Average Differences**

**~33 km**

**~20 km**

- Nardi et al.

## 09/2006, v2.02

**Ozone LIDAR Comparisons with HIRDLS****Statistical Summary: Average Differences**

- Data: May 2006

- Nardi et al.

## Summary

**Ozone accuracy  at 10-2 mb is several percent **
**Ozone accuracy  at 30-10 mb is 10 % or better (biased low)**
**Current lower limit of valid ozone data is 50 mb (accuracy 20-40%, biased low)**
**HIRDLS has high vertical resolution capability.**
_**AVENUES TOWARD IMPROVED OZONE-PRODUCT / COMPARISONS**_
- Improved temperature retrieval (biased high) will produce increase in O3.
- Improvement in pointing algorithm
- Continued improvements Kapton correction
- Continued improvements open area correction
- Continued improvements treatment of cloud features

-  **(from Bruno Nardi et al.)**

##  MLS provisional version 2.1 data versus version 1.5 data: O3                                                                                            

**Standard O**3** Product**

- The differences                     (V2.1 – V1.5) are fairly constant (systematic)   with latitude.
- percent differences shown here                                  - based on 17-day averages, from                 available v2.1 MLS data

- V2.1

- V1.5

- Froidevaux et al

##      MLS provisional version 2.1 data: O3 

- The ozone differences (global averages)  from V1.5 to V2.1 are quite reproducible from day to day and over    more than         1 year
- - based on a few days that have been reprocessed

- Froidevaux et al

## Changes to MLS ozone in v2.1: impact on comparisons

**Changes to MLS ozone in v2.1: impact on comparisons**

**Satellite Data (some examples)                                                                                                      **17 days (~ 200 profiles) of MLS coincidences with SAGE II (72S to 49N, with gaps)

**SAGE II**
**MLS v1.5**
**MLS v2.1**

**v1.5 – SAGE II**
**v2.1 – SAGE II**

- The comparison versus SAGE II is generally improved for v2.1
-  stratospheric and mesospheric differences are reduced
-  within ~5%                           from 150 to 0.15 hPa             (for these profile averages)
-  also seems better                         at 315 hPa
-  will await more (v2.2) data for more analyses vs latitude (and time)

- The small positive change in slope versus height is of the right sign and magnitude to reduce the negative slope that was (often) found in ozone comparisons for MLS v1.5 data.

- Froidevaux et al

## Comparisons with O3 Sonde Data

**Aura Validation Meeting ****	****	****	****	****	****	****                    9/11/2006**

**Aura Science Team Meeting ****	****	****	****	****	****                Jiang et. al.      9/11/2006**

**MLS Ozone v2.1, v1.5 & Sondes**

** ****Based on 17 days of MLS v2.1 data 58 coincidence profiles (available on AVDC)**
** ****MLS v2.1 O3 shows better agreement with sonde data than v1.5**
** ****within 5% from ~ 20 to 100 hPa**
** ****10% in US, MLS biased lower **
** ****still biased high in UT,                        but improved over v1.5**
** ****Upper stratospheric sonde data quality probably influences poorer comparisons there **
** ****As for comparisons vs satellite data, we see the change in slope for MLS v2.1**

- MLS V2.1

- MLS V1.5

- sondes

## Comparisons with O3 LIDAR Data

**Aura Validation Meeting ****	****	****	****	****	****	****                    9/11/2006**

**Aura Science Team Meeting ****	****	****	****	****	****                Jiang et. al.      9/11/2006**

**MLS Ozone v2.1, v1.5 & LIDAR**

**Based on 17 days of MLS v2.1 data 18 coincidence profiles (available on AVDC) **
**MLS v2.1 O3 shows better agreement with LIDAR data than v1.5**
** ****v2.1 – lidar within 5-10%                                for P between 215 and 0.7 hPa **
** ****MLS – sondes differences near 10 hPa is not observed in LIDAR comparison**
**MLS is biased high at 315 hPa**

- MLS V2.1

- MLS V1.5

- Lidar

## MLS provisional V2.1 Ozone data 

- profiles have a slight slope change (‘lifting’ of profiles) versus v1.5 (mainly because of changes to temperature and tangent pressure)
- this reduces the sloping differences versus several other datasets
- V2.1 ozone shows better overall agreement than V1.5 compared to other correlative measurements (e.g. within 5-10% between 150 and 0.15 hPa)