# Presentation: 290213

## Overview Report :  Aura Validation Working Group Meeting          (L. Froidevaux)

- impact of stray/scattered light on grd-based and OMI measurements.

- Mentioned IONS-campaigns, and  mobile trailer for further  validation and science studies                                      + potential plans for  the future.

**Overview Report :  Aura Validation Working Group Meeting         ** (L. Froidevaux)

## P-AVE   	= Polar AURA Validation Experiment 2005 1/24-2/9 (M. Schoeberl, E. Jensen)
H-AVE 	= Houston AURA Validation Experiment, 2005 6/9-7/7 (P. Newman, D. Fahey)
CR-AVE	= Costa Rica AURA Validation Experiment, 2006 1/9-2/11 (P. Newman, E. Jensen)
INTEX-B   	= Intercontinental Chemical Transport Experiment, 2006 3/1–5/12 (M. Gaunce, H. Singh, M. Schoeberl )
TC4      	= Tropical Composition, Cloud and Climate Coupling, 2007 6/26–8/13 (D. Starr, B. Toon)
ARCTAS	= Arctic Research of the Composition of the Troposphere from Aircraft and Satellites, 2008 Apr 1-21 (K. Shiffer, D. Jacob, H. Singh)
START08	= Stratosphere-Troposphere Analyses of Regional Transport, 2008 4/ 21- 5/16 & June 16-28, (E.Atlas, L. Pan, K. Bowman)

SAUNA	= Sodankylä Total Column Ozone Intercomparison, 2006, 3/27-4/12
MOHAVE	= Measurements Of Humidity in the Atmosphere: Validation Experiments, 2006 Oct 14-28; 2007 Oct1-15 (T. Leblanc, S. McDermid)
WAVES    	= Water Vapor Val. Exp., Sum 2006&07, Win 2008: H2O, O3, T, balloon sondes, lidar &..., Beltsville, MD (D. Whiteman)
Large Bal.	= Large Balloon payloads, 9-10/2005, 1/2007

ACE-FTS	= Atmospheric Chemistry Experiment on Canadian satellite SCISAT-1, (P. Bernath, K. Walker)
CALIPSO	= Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (D. Winker, J. Pelon)
HALOE	= Halogen Occultation Experiment (J. Russell)
SAGE III	= Stratospheric Aerosol and Gas Experiment (P. McCormick)
MIPAS	= Michelson Interferometer for Passive Atmospheric Sounding on European satellite ENVISAT 
COSMIC	= GPS receivers on, launch June 2006

**CALIPSO**

**ENVISAT / MIPAS**

**HALOE/UARS**

**SAGE III**

**2005**

**2006**

**2007**

- 2008

**INTEX-B**

**H-AVE**

**TC****4**

**HIRDLS ****Review**

**ARCTAS**

**P-AVE   ****	****= Polar AURA Validation Experiment 2005 1/24-2/9 (M. Schoeberl, E. Jensen)**
**H-AVE ****	****= Houston AURA Validation Experiment, 2005 6/9-7/7 (P. Newman, D. Fahey)**
**CR-AVE****	****= Costa Rica AURA Validation Experiment, 2006 1/9-2/11 (P. Newman, E. Jensen)**
**INTEX-B   ****	****= Intercontinental Chemical Transport Experiment, 2006 3/1–5/12 ****(M. Gaunce, H. Singh, M. Schoeberl )**
**TC****4****      ****	****= ****Tropical Composition, Cloud and Climate Coupling, 2007 6/26–8/13 (D. Starr, B. Toon)**
**ARCTAS****	****= ****Arctic Research of the Composition of the Troposphere from Aircraft and Satellites, 2008 Apr 1-21 (K. Shiffer, D. Jacob, H. Singh)**
**START08****	****= ****Stratosphere-Troposphere Analyses of Regional Transport, 2008** **4/ 21- 5/16 & June 16-28, (E.Atlas, L. Pan, K. Bowman)**
**SAUNA****	****= Sodankyl****ä**** Total Column Ozone Intercomparison, 2006, 3/27-4/12**
**MOHAVE****	****= ****Measurements Of Humidity in the Atmosphere: Validation Experiments, 2006 Oct 14-28; 2007 Oct1-15 (T. Leblanc, S. McDermid)**
**WAVES    ****	****= Water Vapor Val. Exp., Sum 2006&07, Win 2008: H2O, O3, T, balloon sondes, lidar &..., Beltsville, MD (D. Whiteman)**
**Large Bal.****	****= Large Balloon payloads, 9-10/2005, 1/2007**
**ACE-FTS****	****= ****Atmospheric Chemistry Experiment on Canadian satellite SCISAT-1, (P. Bernath, K. Walker)**
**CALIPSO****	****= ****Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation** **(D. Winker, J. Pelon)**
**HALOE****	****= ****Halogen Occultation Experiment (J. Russell)**
**SAGE III****	****= ****Stratospheric Aerosol and Gas Experiment (****P. McCormick)**
**MIPAS****	****= ****Michelson Interferometer for Passive Atmospheric Sounding on European satellite ENVISAT **
**COSMIC****	****= GPS receivers on, launch June 2006**

**HIRDLS Operational**

**P-AVE**

**CR-AVE**

**START08**

**HIRDLS** Validation

- 2004

- Launch

**ST30**

**ST13**

**ST23**

**WAVES****’06**

**WAVES****’07**

**WAVES’08**

**SAUNA**

- V003(v2.04.09)

- V002(v2.02.07)

**MOHAVE**

**MOHAVE****2**

**L.Bal.**

**L.Bal.**

- V004

## HIRDLS Validation

- _Temperature_	Range:	1 - 400 hPa
- _Ozone_		Range: 	1 - 260 hPa (mid-high Lat), 1-100 hPa (tropics)
- _Nitric Acid_	Range: 	10 - 161 hPa  ; ACE-FTS, MLS comparisons, ...
- _Clouds/Aerosol_	Range:	10 - 422 hPa  ; CALIPSO comparisons
- _12.1 μm Extinction_	Range:	20 - 215 hPa  ; new product
- _CFC-11_		Range: 	26 - 287 hPa  ;   MIPAS comparisons
- _CFC-12_		Range: 	10 - 287 hPa  ;   MIPAS comparisons
- 		_**Vertical Resolution**_**: ****	****~1 km  **
**Currently working toward future release:**   H2O, CH4                                                      **[see Posters: Gille;  Eden]**
- NO2, N2O, ClONO2, N2O5 – Correction improving.
***HIRDLS [V4] Data Quality Document: on the NASA DISC [link on the AVDC]***

**HIRDLS** Validation

##  MLS: Overview of progress for cal/val issues

-  Some important activities relate to the upcoming (2009) v3 retrievals
-   > CO: expect reduction of biases in UT CO; use of AVE CO profiles as “truth”                                         	 points to a sloping radiance artifact; may get corrected in v3 data.
-   > O3: higher vertical resolution product is planned
-   > H2O & RHi will be useful products at 383 hPa (tropics) / 464 hPa (high
-      lats.); also, artificial ‘kink’ in profiles near 30 hPa will be eliminated.
-   > HCl is very useful for studying chlorine processing issues; however, an issue
-       has emerged in terms of the determination of its slow long-term decrease
-       (diff. bands giving diff. results; version 2 trend seems too slow)
-   > HOCl ( p < 20 hPa) values will increase (by 20-30%)
-        should agree well with balloon data
-   >  Preliminary results from v3 data processing algorithms indicate that retrieval
-        of CH3Cl significantly reduces ClO LS bias   add CH3Cl as MLS product
-   - HNO3: Good overall agreement found in HNO3/O3 correlations from in situ
-       data vs balloon & satellite data (MLS, ACE-FTS) [*Popp et al.,* JGR, sub.]
-   - OH & HCN: longer-term studies vs grd-based data & models exist/continue
-         > JPL FTUVS OH column comparisons
-         > Univ. of Edinburgh studies for HCN

## MLS: cal/val issues

**Additional correlative data needs? **
-      - additional cloud information (particle size distribution)
-        would be very useful to help reduce uncertainties in IWC product
-        (given very large range of model values for IWC)
-      - additional balloon data can be useful
-        [e.g. for HCl, HOCl at midlatitudes; possibly ClO in polar regions]
- -  Longer-term validation of interannual changes will be based mostly on continuing comparisons versus other satellite datasets and** **on NDACC data
-   MOZAIC and SHADOZ useful for continued calibration/validation efforts for upper tropospheric and lower stratospheric products.
-  One can always do more validation versus existing correlative data
-    > most biases/issues already identified for MLS products
-       [see JGR special issue on Aura validation, 2007/2008]
-    > however, some things are also very tough to validate                                             	(e.g., retrieved profiles in cloudy conditions)

## TES  Version 3 reprocessing is complete; CH4, Limb Products are provisionally validated.

**TES**_** **_**Version 4 data**
-           has undergone *preliminary* validation analyses
-           (processing began in early Sep 2008)                                                                          **T:** Improvements to nadir temperature key feature of V04 data
- Bias improved to less than 0.5K compared to sondes at nearly all altitudes
- Bias at 400 hPa is ~0.7K
*See R Herman et al. poster presentation on Wednesday*
**CH****4****:** TES nadir methane retrievals processed as “representative tropospheric VMR” are biased 3-4% high relative to aircraft data
*See V Payne et al., presentation – Wed 4:45*
**O****3****:** Minor changes to ozone retrievals
- - Fewer cases with anomalous high O3 near surface in V04
**CO, nadir H****2****O, HDO**, limb products consistent with V03

## TES V03

| Species | Validation Status |
| --- | --- |
| Nadir Ozone | Validated Stage 2 |
| Nadir Carbon Monoxide | Validated Stage 2 |
| Nadir Water | Validated Stage 2 |
| Nadir Temperature | Validated Stage 2 |
| Sea Surface Temperature | Validated Stage 2 |
| Land Surface Temperature/Emissivity | Provisionally Validated |
| Nadir Methane | Validated Stage 2 |
| Nadir HDO | Validated Stage 1* |
| Limb Nitric Acid | Provisionally Validated |
| Limb Ozone | Provisionally Validated |
| Limb Temperature | Provisionally Validated |
| Limb Water | Beta – Used as interferent for retrievals of other limb products |

**TES V03**

** ****Plan to upgrade from yellow to green for mid-2009 (V04 data)**

## OMI

|  | Brewer |  | Dobson |  |
| --- | --- | --- | --- | --- |
|         OMI 
      retrieval | <O-G>/G | (O-G) | <O-G>/G | (O-G) |
|       DOAS | 0.48 % | 2.75 % | 0.07 % | 1.65 % |
|       DOAS* | -0.56 % | 0.20 % | 0.09 % | 1.60 % |
|       TOMS | -0.50 % | 2.70 % | -0.63 % | 1.03 % |
|       TOMS* | -1.45 % | 0.42 % | -0.65 % | 1.06 % |

**Data Courtesy : Dr . Dimitris Balis – Aristotle University of Thessaloniki – OMI AO 2925 **

**OMI**
**Column Ozone:                                                                              ****- very good overall agreement (TOMS & DOAS vs ground-based)**
**- refinements being worked on, in particular for high latitudes                                 where high SZA and T-dependent effects lead to larger diffs.                      (issues include UV absorption cross sections) **

- * No South Pole (lat > 75 S)

**TOMS - DOAS**

## - Aerosols: AOD scatter has been reduced in the collection 3 data.                                                                                                                                        - NO2  validation vs ground-based and other satellites (+ retrieval changes) continuing.                     - Ozone profiles: new results (from different retrievals, KNMI and U.S.; overall nice agreement versus MLS O3 – but coarse vertical resolution and some oscillations.                    - NO2 is highest val. priority; toughest validation is for BrO, OClO, H2CO, CHO-CHO

| OMI Data Product | Released | Status |  |  |  |
| --- | --- | --- | --- | --- | --- |
| Level 1B | Public |  |  |  |  |
| Total Column Ozone (TOMS) | Public |  |  |  |  |
| Total Column Ozone (DOAS) | Public |  |  |  |  |
| Aerosol (NASA – AI AOT AAOT) | Public |  |  |  |  |
| Aerosol (KNMI – AOD SSA) | Public |  |  |  |  |
| Nitrogen Dioxide Total Column | Public |  |  |  |  |
| Nitrogen Dioxide trop. column | Public |  |  |  |  |
| Cloud Height and Fraction O2-O2 | Public |  |  |  |  |
| Cloud Height & Fraction Raman | Public |  |  |  |  |
| Surface-UV | Public |  |  |  |  |
| Sulphur Dioxide (STL TRM PBL) | Public |  |  |  |  |
| Formaldehyde | Public |  |  |  |  |
| Bromine Oxide | Public |  |  |  |  |
| Chlorine Dioxide | Public |  |  |  |  |
| Ozone Profile | Provisional |  |  |  |  |

- - Aerosols: AOD scatter has been reduced in the collection 3 data.                                                                                                                                        - NO2  validation vs ground-based and other satellites (+ retrieval changes) continuing.                     - Ozone profiles: new results (from different retrievals, KNMI and U.S.; overall nice agreement versus MLS O3 – but coarse vertical resolution and some oscillations.                    - NO2 is highest val. priority; toughest validation is for BrO, OClO, H2CO, CHO-CHO

**Use the latest data version (collection 3)!**

- Volcanic plume SO2 validation

## Preliminary Summary of AquaVIT (H2O intercomparison)

**Motivation: ** Lack of agreement/consistency between in situ and remote water vapor measurements below 10 ppm in the UT/LS
**Response: ** Conduct a ground-based in situ intercomparison campaign with key instruments and investigators

**Preliminary Summary of AquaVIT (H****2****O intercomparison)**

- AVE campaign data

- The AquaVIT intercomparison was a success                      – but will not by itself resolve AVE discrepancies.
**For core instruments: AIDA-TDL, CFH, FISH, FLASH, HWV, JLH**
- For 1-10 ppm, avg deviations (from avg) within  ± 10 %
- Absolute standard for multi-instrument calibration not yet developed
**Implications for field observations**
- Observed avg differences between CFH and HWV are smaller than in field observations (but have same sign)
- Larger differences may be caused by specific sampling issues on the respective platforms

- [by D. Fahey]

##   H2O (continued)

-   MOHAVE-type campaigns [Thierry Leblanc et al.], using ground-based H2O Raman lidars are pushing H2O up to 15-20 km (but probably also requires a number of years of careful intercalibration work among various measurements)                                                                               >  Note: when ready, this could be coupled to _aircraft measurements_, to help resolve H2O  cal./val. issues between in situ and sonde/satellite data                                                             _Questions for the future (TBD)_:                                                                                     Will such a validation path be pursued (financed/organized)?                                 What will follow-up to AquaVIT be?
- -  Also, GRUAN (GCOS Reference Upper Atmosphere Network) is being set up by H. Vömel et al., aiming to provide high vertical resolution reference data in the troposphere and stratosphere for T, H2O (rel. humidity), pressure, winds, ...                                                                          >  Besides satellite validation issues, such a network should address atmospheric and long term climate issues

## OMI Validation with theGround-Based WSU MFDOAS Spectrometer(G. Mount et al.)

**SO****2**

- The good,             the “serendipitously” good,    and the mystery

- More campaigns and OMI validation planned (glyoxal also).

**HCHO**

## Also, various posters at this meeting (and talks)                            present(ed) updates on calibration/validation studies                                 relating to Aura measurements                                                   [current and future]