OMI Overview

OMI Overview

Prof. Dr. Pieternel Levelt

KNMI, TUE

The Netherlands

OMI Zoom mode 12x13 km2

Mexico City and suburbsOMI NO2, January 20, 2005Courtesy: Veefkind, KNMI

Prof.Dr.P.F.Levelt, KNMI, TUE, June11,2008, NIVR

International OMI TeamInternational OMI Science team• PI (KNMI): P.F. Levelt• dep.PI (KNMI): J.P. Veefkind• co-PI (FMI) J.Tamminen• US ST Leader (NASA GSFC): P.K. Bhartia• …. And about 60 - 80 scientists

Industry• Dutch: DS, TNO-TPD, SRON• Finnish: VTT, Patria• USA: Northrop GES USA

Dutch, Finnish and US Space Agencies

• NIVR, FMI and NASA• OMI is a Dutch-Finnish Instrument

on the NASA spacecraft EOS-AuraLaunch: July 15, 2004

OMI is now also a third party

mission from ESA


Ozone hole 2007

Dutch National GeographicNovember 2008Instruments in TheNetherlands


OMI NO2 Weekly Cycle over The Netherlands

Period Dec 2004 - Nov 2005, Normalized for Monday


Daily OMI Air Pollution Observations (1)

Tropospheric NO2 for Tue-6, Wed-7, Thu-8 and Fri-9 May 2008. Image courtesy: Quintus Kleipool (KNMI)

Tuesday Wednesday

Thursday Friday


Daily OMI Air Pollution Observations (2)

Tropospheric NO2 for Sat-10, Sun-11, Mon-12 and Tue-13 May 2008, including the Pentecost weekend (11-12 May). Image courtesy: Quintus Kleipool (KNMI)

Saturday Sunday

Monday Tuesday


SCIAMACHY and OMI at resp. 10:00 and 13:30 local time overpass

Courtesy: K. F. Boersma et al.

Orbit choice : first data on diurnal cycle from space


Air QualityGreek Forest fires in august 2007: enhanced aerosols, NO2 and CO from OMI and SCIAMACHY

OMI aerosol (right)

and NO2

(below)

Greek Forest fires in august 2007: enhanced aerosols, NO2 and CO from OMI and SCIAMACHY


SO2 Mount Etna

Mount Etna13,14,15 and 16May 2008

Carn et al.


OMI cloud “top” pressure

With CloudSat, we can examine radiative transfer in realistic extended clouds and confirm the hypothesis.

Cloudsat radar reflectivities

Layer optical depths derived from MODIS/CloudSat.

Cloud pressures simulated from these data

Profile # 1 2 3 4 5

OMI cloud pressuresMODIS cloud-top pressures

Slide from Vassilkov, NASA GSFC.


Back upHCHO

Trop O3

Glyoxal

NO2

October 2005: collection 3


Ground Based In-Situ Data

• LML Dutch air quality network, www.rivm.nl/lml• Regional, City and Street stations• Mean yearly value per station for 12:00 to 14:00 hrs


Comparison with the LML


Zoom-in over France

Cities of the size >100,000 habitantsCities of the size >100,000 habitants


Detection Limit of Tropospheric NO2

The detection limit is defined as the minimum difference in tropospheric NO2 in a yearly mean that is statistically meaningful.

Smaller values are better

Detection Limit Confidence 67% Confidence 95% Absolute Relative Absolute Relative OMI 1.9 1014 1 4.3 1014 1 GOME-2 5.2 1014 2.8 1.5 1015 3.5 SCIAMACHY 1.2 1015 6.5 4.3 1015 9.9

OMIGOME-2SCIA

Area observed 60x30 km2


Aura Spacecraft

De Bilt Washington

Before re-phasing

After re-phasingOMI monthly spatial zoom-in measurements

• Aura FMU anomaly• Aura rephasing

See presentation Jacques Claas today


Instrument and calibration status

OMI flight model

• OMI instrument is very stable • OMI operations 99,9 %• Calibration daily OPF updates for dark current corrections:Collection 3

Anomalies OMI:• FMU anomalyAll mechanism commands have been adjusted• New OMI anomaly for outer swath last year• Another comparable OMI anomaly recently on around row 40 swath position

For last 2 anomalies :- level 1 and 2 data are affected- potential cause is identified, but difficult to confirm- possibility correction mechanism is investigated

See Dobber’s presentation today and tomorrow


Collection 3 Processing Summary


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 and Good for Science

Validated and Some Problems

Validated butUse with Caution

Validation Preliminary

Not Publicly Available


OMI – MLS Ozone Profiles

Preliminary results forOMI vs MLS ozone profiles

Distance < 100 kmSame orbit


Status of OMI Data Products (collection 3)Product Provisional

releaseValidated Stage 1 release (Public)

Algorithm originator

- Level 1B Released Released KNMI

- Total Column Ozone (TOMS)

Released Released NASA GSFC

- Total Column Ozone (DOAS)

Released Released KNMI

- Aerosol (UV and multi-l) Released Released NASA GSFC & KNMI

- NO2 total and trop.

column

Released Released KNMI & NASA GSFC

- Cloud Height (O2-O2) Released Released KNMI

- Cloud Height (Raman) Released Released NASA GSFC

- Surface UVB Released Released FMI & NASA GSFC

- HCHO Released Released Harvard

- SO2 Released Released NASA GSFC

- BrO Released Released Harvard

- OClO Released Released Harvard

- O3 Profile Released Not released KNMI

KNMI OMI website:(http://www.knmi.nl/omi)

Instrument and level 0-1b data processing overview:(http://www.knmi.nl/omi/research/calibration/instrument_overview)

Data: NASA GSFC DISC (http://disc.gsfc.nasa.gov/Aura/OMI)

NRT data: TEMIS website (http://www.temis.nl)

VFD data : Very Fast Delivery (http://omivfd.fmi.fi)

IEEE Aura special Issue: instrument, algorithm and first results papers (March 2006)JGR special issue: validation papers (2008)

http://www.knmi.nl/omi

http://omivfd.fmi.fi/


This meeting

Main Topics:

• AQ and Climate session• Validation session• OMI anomaly• Blue team review and preparation forreview in November for Aura extension:• Mark and Anne will come Wednesday• Future missions: TROPOMI


Back up


Spatial Resolution

OMI Zoom 12x13 km2 OMI 24x13 km2

Mexico CityJanuary 20, 2005

Approx. GOME-2 72x39 km2


Detection Limit Test

• Assume two areas with different yearly average NO2 concentrations;

• Simulate the measured NO2 assuming a variation of 100% and a cloud contamination of 50%;

• Sample the simulated NO2 with a sensor with a certain spatial and temporal sampling and measurement uncertainty;

• Using a statistical test at 67 and 95% confidence level, determine the minimum detectable difference.


Ozone Monitoring Instrument OMI

• UV and VIS backscatter instrument (270 - 500 nm)

• Wide swath telescope yields daily global maps (2600 km)

• Urban scale resolution is best ever for air quality measurements from space

(13 x 24 km2)

Heritage: GOME, SCIAMACHY, GOMOS and TOMS

OMI is now also a third party mission from ESA


First comparisons of MODIS & OMI cloud pressures: Hurricane Katrina (Joiner et al., GRL, 2006)

Some differences expected; Cloudsat data not available at the time.

Spiral structure seen in OMI cloud pressures, but not in MODIS cloud-top pressure. Hypothesis: UV radiation penetrates deep inside a cloud because OMI UV channels see through high thin cirrus to lower water clouds with band structure.


Instrument and calibration status

OMI flight model

• OMI operations 99 %• Calibration daily OPF updates for dark current corrections:Collection 3

Anomalies OMI:• FMU anomalyAll OMI commands have been adjusted• New OMI anomaly for outer swath last year• Another comparable OMI anomaly recently on around row 40 swath position

For last 2 anomalies :- level 1 and 2 data are affected- potential cause is identified, but difficult to confirm- possibility correction mechanism is investigated

See Dobber’s presentation today and tomorrow

OMI Overview

Documents

Transcript of OMI Overview