Air Quality Observations from OMI on EOS/Aura

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Air Quality Observations from OMI on EOS/Aura
HCHO and CHO-CHO(and NO2 and Tropospheric Ozone)

• Thomas P. Kurosu, Xiong Liu, Kelly Chance (CfA)
• Edward Celarier (GSFC)
• Wallace McMillan (UMBC)
• AGU Joint Assembly
• Fort Lauderdale, FL 26-30 May 2008

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Outline

• Instrument/Algorithm Overview
• Collection 3 Product Status
• HCHO and CHO-CHO Global Distribution
• Case Study Indonesian Biomass Burning
• CHO-CHO/HCHO Ratios
• OMI HCHO, CHO-CHO, Trop. O3, NO2 and AIRS CO
• Outlook

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OMI Instrument and L2 Fitting Algorithm Overview
The Instrument
Dutch (KNMI) / Finnish (FMI) instrument with US
(NASA GSFC) participation On EOS Aura
sun-synchronous, 1338h equator crossing time,
ascending node part of the A Train Nadir-viewi
ng CCD spectrometer, 270-500 nm spectral range
(divided into threechannels) 0.42-0.63 nm
spectral resolution Daily Global Coverage 60
across-track pixels (no scanning!) 2,600 km
total swath width ground pixel size 1324 km2 at
nadir
Our L2 Fitting Algorithm(s)
Non-linear least-squares (direct)
fitting Includes contributions from interfering
absorbers, plus Ring, sampling correction, common
mode, closure polynomials May use radiance
reference for soft calibration (striping
correction) HCHOCHO-CHO air mass factors
derived from GEOS-Chem shape factors and the
LIDORT radiative transfer model Tropospheric
ozone/O3 profile retrieval based on optimal
estimation, coupled with LIDORT
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X.Liu et al. Poster A33-A13
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Collection 3 Product Status
Collection 3 Latest version of radiance and
irradiance products
Level 1b (radiance and irradiances)
Dynamic dark current correction (daily) has
greatly improved the products, which has a direct
impact on any Level 2 products derived from them
Our L2 Products
Significantly reduced across-track striping due
to combination of daily dark current correction
and soft calibration All our standard data
products (BrO, HCHO, OClO) publicly released
(April/May 2008 onward) complete reprocessing to
be initiated soon BrO, HCHO, and OClO now
compare well with independent measurements (e.g.,
SCIAMACHY) CHO-CHO (science product) to be made
operational/publicly available soon (pending
validation) Tropospheric ozone/O3 profiles
(science product) requires more work (speed-up)
before it can go into production
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HCHO, CHO-CHO Overview
HCHO
Volatile organic compound, produced from methane
oxidation and isoprene emissions main sinks are
photolysis and reaction with OH (1.5h life
time) OMI retrieval wavelength window 327.5
356.5 nm
CHO-CHO
Volatile organic compound, produced from
oxidation of a large number of other, mostly
aromatic VOCs main sinks are photolysis and
reaction with OH (1.3h life time) observed in
Mexico City during MILAGRO, and in the Pearl
River Delta (R. Volkamer, NCAR) Unlike HCHO not
directly affected by vehicle emission, hence a
better indicator for VOC oxidation (photochemical
smog) OMI retrieval wavelength window 433.5
465.5 nm First space-based CHO-CHO observation
made by OMI!
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OMI HCHO August 2006
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OMI CHO-CHO August 2006
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? October 2006
HCHOCHO-CHO August 2006
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CHO-CHO/HCHO Ratios October 2005-2007
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(No Transcript)
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Indonesia 2005-7 OMI HCHO, CHO-CHO
, tropospheric O3
, NO2
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Outlook

• Continue validation of HCHO
• Extensive comparison with ground-based and
  satellite observations
• Start validation of CHO-CHO
• Comparison with (unfortunately sparse)
  ground-based and other satellite observations
• Look closer at CHO-CHO/HCHO and CHO-CHO/NO2
  ratios
• Comparison with existing ground-based
  measurements
• Studies on biomass-burning and anthropogenic
  emissions (improvement of air quality
  indicators?)
• Process more data
• Studies on seasonal variability
• Push limits of temporal averaging
• Most likely more than one day, but hopefully less
  than a month 3-5 days?