# Presentation: 174934

## OMI Validation Status

**Mark Kroon - KNMI**
**(o.b.o. the OMI validation team)**
**Aura Science Team Meeting**
**Sheraton Columbia Hotel**
**Columbia, MD. 25 October 2008**

## JGR Aura Validation Issue

| Topic | # |
| --- | --- |
| Level 1B | 3 |
| Aerosols | 3 |
| Clouds | 3 |
| Nitrogen Dioxide | 7 |
| Ozone | 11 |
| Sulphur Dioxide | 2 |
| Surface-UV | 1 |
| VF Delivery | 1 |
| Total | 31 |

- 31 out of 67 papers related to OMI (on both validation and science)!
- High quality peerreview and webpublished papers!
- 10 papers from OMI AO!
*Balis, Brinksma, Curier, Ionov, Kramer, Krzyścin, Migliorini, Shavrina, Sneep, Tanskanen. *

## JGR Aura Validation Issue

**JGR Aura Validation Issue**

## Validation Status COL3

| 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 tropospheric column | Public |  |  |  |  |
| Cloud Height and Fraction O2-O2 | Public |  |  |  |  |
| Cloud Height and Fraction Raman | Public |  |  |  |  |
| Surface-UV | Public |  |  |  |  |
| Sulphur Dioxide (STL TRM PBL) | Public |  |  |  |  |
| Formaldehyde | Public |  |  |  |  |
| Bromine Oxide | Public |  |  |  |  |
| Chlorine Dioxide | Public |  |  |  |  |
| Ozone Profile | Provisional |  |  |  |  |

- Validated
- No Issues

- Validated and Some Problems

- Validated butUse with Caution

- Validation Preliminary

- Not Publicly Available

## Total Ozone Column OMTO3

**Image(s) Courtesy : Dr . Dimitris Balis – Aristotle University of Thessaloniki – OMI AO 2925 **

- 10

- 10

## Total Ozone Column OMDOAO3

**Total Ozone Column OMDOAO3**

**Image(s) Courtesy : Dr . Dimitris Balis – Aristotle University of Thessaloniki – OMI AO 2925 **

- 10

- 10

## Ground Based Validation

|  | Brewer |  | Dobson |  |
| --- | --- | --- | --- | --- |
|  | <O-G>/G | (O-G) | <O-G>/G | (O-G) |
| OMI DOAS | 0.483 % | 2.754 % | 0.070 % | 1.653 % |
| OMI DOAS* | -0.555 % | 0.200 % | 0.086 % | 1.601 % |
| OMI TOMS | -0.504 % | 2.704 % | -0.631 % | 1.032 % |
| OMI TOMS* | -1.450 % | 0.425 % | -0.645 % | 1.064 % |

- * No South Pole (lat > 75 S)

**Ground Based Validation**

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

## Total Ozone Column

**Total O3 Column Difference for October 2005**

- OMI TOMS V8.5 - DOAS v1.0.5 [DU]

## Look-Up-Table Interpolation

**Linear Versus Spline Interpolation**

## Effective Ozone Temperature

- 2005-09 Effective Ozone Temperature

- 2005-09 Relative Ozone Column Difference

- DOAS O3 Temperature (oC)

- (TOMS-DOAS)/DOAS

## Effective Ozone Temperature

- Relative ozone differences partially explained by temperature effects.
- OMDOAO3 made independent of effective ozone temperature.
- How about OMTO3 and Brewer and Dobson? Future work!
- Remaining issue at high solar zenith angles! Future work!

## OMI – MLS Ozone Profiles - Match

**OMI – MLS Ozone Profiles - Match**

- Preliminary results forOMI vs MLS ozone profiles
- Distance < 100 kmSame orbit

## OMI – MLS Ozone Profiles - Week

- Preliminary results for OMI vs MLS ozone profiles
- Distance < 100 km and Same orbit

## OMI – MLS Ozone Profiles - 2006

## OMI – MLS Ozone Profiles - 2006

## OMI – MLS Ozone Profiles - 2006

## OMI – GOMOS Ozone Profiles

**Image(s) Courtesy : Dr . Johanna Tamminen - FMI**

## Nitrogen Dioxide Total Column

**Image Courtesy : Dr. Dmitry Ionov – CNRS – OMI AO 2926**

- SAOZ (ECS2 vs. COL3) for OMI 2004-2007

## Nitrogen Dioxide Tropospheric Column

**Image Courtesy : Dr. Jennifer Hains – KNMI**

- + OMI pixel < 650 km2
- + OMI pixel > 650 km2
- + SCIAMACHY

## Aerosols Optical Depth - UV

**Images Courtesy : Dr. Omar Torres – Hampton**

- Collection 2

- Collection 3

- Omar Torres: *“Collection 3 data shows significant improvement in the accuracy of retrieved AOD relative to collection 2 results. Noise level significantly reduced in monthly averages.”*

## Aerosols Optical Depth – 

**Images Courtesy : Dr. Remco Braak – KNMI**

- OMI data is land only and ‘MODIS cloud fraction screened’ 'Q12' means using monthly mean surface reflectivity data [Quintus Kleipool (KNMI)].

**'Q12'**

## Sulphur Dioxide Total Column

- Mark K: Would you consider the OMSO2 data product to be of category 1 (validated), 2 (some issues) or 3 (caution)?
**Nick K: Volcanic SO2 data (TRL 2.5, TRM 7.5 and STL 17 ) retrieved with linear fit algorithm are in category 2! **
*Add 1: Products are accurate for small to moderate volcanic SO2 plumes ( < 50 DU). Main problem is guessing SO2 altitude. *
*Add 2: Current volcanic data will underestimate SO2 for large eruptions (> 100 DU). *
*Add 3: Boundary layer SO2 (PBL) is in category 3, mostly because of high noise (StDev ~1.5DU for optimal conditions) that is comparable or larger than real anthropogenic signals.*

**Images Courtesy : Dr. Nick krotkov – GSFC**

## Sulphur Dioxide Total Column

**Images Courtesy : www.temis.nl**

## Bromine Oxide

**Images Courtesy : Dr. Thomas Kurosu – Harvard-Smithsonian Center for Astrophysics**

## Formaldehyde

**Images Courtesy : Dr. Thomas Kurosu – Harvard-Smithsonian Center for Astrophysics**

## Chlorine Dioxide

**Chlorine Dioxide**

**Images Courtesy : Dr. Thomas Kurosu – Harvard-Smithsonian Center for Astrophysics**

- Thomas Kurosu - Harvard-Smithsonian Center for Astrophysics
- “*There is a huge difference between those three products between ECS2 and COL3: COL3 versions are much improved over ECS2. In fact, use of ECS2 data is STRONGLY discouraged ..*.”
*“**The Col 3 versions are much improved in across-track striping (meaning there is less of it), to the point that we currently discourage the use of the "destriped columns"* ...

## OMI Validation Priorities

**Nitrogen Dioxide (NO2)**
-  Air pollution, anthropogenic proxy, emission estimates
-  Sparse correlative data, retrieval challenges
**Ozone (O3)**
-  Air pollution, health hazard, ozone (hole) recovery
-  Remaining retrieval challenges (tot-O3C, trop-O3C)
**Aerosols**
-  Air pollution, retrieval challenges, physics of aerosols
**Sulphur Dioxide (SO2)**
- Air pollution, altitude and emission estimates, aviation warning
**Clouds**
- Influence to (tropospheric) trace gas retrievals
**“****Minor” trace gases (BrO, OClO, HCHO, CHO-CHO)**
- Shortage of correlative data in general