MODIS was not designed to supply accurate middle-atmosphere ozone abundances. Ozone profile is not the level 2 product generated operationally from MODIS data at DAAC. However, test retrievals made by Altai State University group show that MODIS has the

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GOAL
MODIS was not designed to supply accurate
middle-atmosphere ozone abundances. Ozone
profile is not the level 2 product generated
operationally from MODIS data at DAAC. However,
test retrievals made by Altai State University
group show that MODIS has the capability to
monitor the ozone profile under clear-sky
conditions at regional scale. To verify this
capability, the MODIS profiles have been compared
with the products from other observing
systems. The aim of this talk is to assess the
quality of the MODIS ozone profiles using
AIRS/Aqua.
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Outline

1. MODIS algorithm for retrieval of vertical ozone
   distribution
2. MODIS atmosphere processing
3. Examples of coverage by MODIS/(TerraAqua) using
   the station located in Barnaul
4. AIRS data
5. MODIS versus AIRS examples
6. Intercomparison results of MODIS and AIRS
   correlative data
7. Intercomparison results of MODIS and lidar
   correlative data
8. Ozone profile variability
9. Conclusion

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MODIS algorithm for retrieval of vertical ozone
distribution

• Predictors
• 12 corrected infrared brightness temperatures
  BTkBTkm-BT0k, k24, 25, 2736
• Estimate of surface pressure (Psur), latitude
  (L), month (M), and percentage of land (fland).
• MOD07 algorithm can be described in the simple
  mathematical form the mixing ozone ratio OZ
  (Pj) (in ppmv) in the pressure level Pj, j1101
  is equal to
• The synthetic regression coefficients tij, tijk
  in the MOD07 (collection 4) have been generated
  for 680 local zenith angles from nadir to 65o and
  the seven zones based on the 11-µm brightness
  temperatures BT31m calculated from the
  MODIS-measured radiances.

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Example of coverage by MODIS/Terra using the
station located in Barnaul
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Example of coverage by MODIS/Aqua using the
station located in Barnaul
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AIRS data

• AIRS experiment on the Aqua platform includes
  the AIRS infrared spectrometer and companion
  Advanced Microwave Sounding Unit. AIRS design
  parameters are
• a 650 cm-1 (15 µm) to 2700 cm-1 (3.7 µm)
  spectral range with 2378 channels
• spectral response function with full widths at
  half maximum of ?/1200 (0.52.3 cm-1)
• noise levels on the order of 0.2 K.
• AIRS/AMSU data products are available from the
  Goddard Space Flight Center DAAC at
  http//daac.gsfc.nasa.gov.
• H. H. Aumann et.al., IEEE Trans. Geosci. and
  Remote Sensing, v. 41, p. 253, 2003
• C. L. Parkinson, IEEE Trans. Geosci. and Remote
  Sensing, v. 41, p. 173, 2003
• J. Susskind et.al., IEEE Trans. Geosci. and
  Remote Sensing, v. 41, p. 390, 2003.

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MODIS versus AIRS
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Intercomparison results of MODIS and AIRS
correlative data. a) Mean ozone profiles of both
data set. b) Mean difference between all the
paired MODIS and AIRS data as a percentage of the
latter. c) Mean difference. d) Standard
deviations of MODIS and AIRS ozone profiles
Gettelman A. et al., Geophys. Research Letters,
v. 31, L22107, 2004
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MODIS versus AIRS
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MODIS versus AIRS
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Intercomparison results of MODIS and lidar
correlative data. a) Mean ozone profiles of both
data set. b) Mean difference between all the
paired MODIS and lidar data as a percentage of
the latter. c) Standard deviations of MODIS and
lidar ozone profiles
a)
b)
c)
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Ozone profile variability (Lidar ozone profiles
measured in Tomsk 14 March, 2000)
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Conclusion
First results of operational retrieval of
atmospheric ozone profile from the MODIS infrared
radiances over Siberian Region are presented. The
modified PGE 03 code, including synthetic
regression retrieval algorithm, PGE 02 and the
IMAPP Processing Package have been used to
retrieve the vertical ozone distributions under
clear-sky conditions. Evaluation of retrieved
ozone profiles is performed by a comparison with
retrievals from the AIRS/Aqua. We demonstrate,
that the MODIS mixing ozone ratio (in ppmv) and
additionally measured temperature information
will be useful tools in regional stratospheric
ozone studies. The main role of MODIS will be
the monitoring of the ozone trends in the
stratosphere at the scale with 5 km 5 km
resolutions.