1. Титульный.

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.

Outline MODIS algorithm for retrieval of vertical ozone distribution MODIS atmosphere processing Examples of coverage by MODIS/(Terra+Aqua) using the station located in Barnaul AIRS data MODIS versus AIRS: examples Intercomparison results of MODIS and AIRS correlative data Intercomparison results of MODIS and lidar correlative data Ozone profile variability Conclusion

MODIS algorithm for retrieval of vertical ozone distribution Predictors: 12 corrected infrared brightness temperatures BTk=BTkm-BT0k, k=24, 25, 27÷36; 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, j=1÷101 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.

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

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

noise levels on the order of 0.2 K. 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 ~ν/1200 (0.5–2.3 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.

MODIS versus AIRS

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

MODIS versus AIRS

MODIS versus AIRS

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)

Ozone profile variability (Lidar ozone profiles measured in Tomsk 14 March, 2000) Ozone number density, 1012 mol cm-3

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.