Ozone columns obtained by ground-based remote sensing in Kiev for Aura Ozone Measuring Instrument validation

Abstract

Ground-based observations with a Fourier transform spectrometer in the infrared region (FTIR) were performed in Kiev (Ukraine) during the time frames August-October 2005 and June-October 2006 within the Ozone Monitoring Instrument (OMI) validation projpct 2907 entitled "OMI validation by ground based remote sensing: ozone columns and profiles" in the frame of the international European Space Agency /Netherlands Agency for Aerospace Programmes/Royal Dutch Meteorological Institute OMI Announcement of Opportunity effort. Ozone column data for 2005 were obtained by modeling the ozone spectral band at 9.6 μm with the radiative transfer code MODTRAN3.5. Our total ozone column values were found to be lower than OMI Differential Optical Absorption Spectroscopy (DOAS) total ozone column data by 8-10 Dobson units (DU, 1 DU = 0.001 atm cm) on average, while our observations have a relatively small standard error of about 2 DU. Improved modeling of the ozone spectral band, now based on HITRAN-2004 spectral data as calculated by us, moves our results toward better agreement with the OMI DOAS total ozone column data. The observations made during 2006 with a modernized FTIR spectrometer and higher signal-to-noise ratio were simulated by the MODTRAN4 model computations. For ozone column estimates, the Aqua Atmospheric Infrared Sounder satellite water vapor and temperature profiles were combined with the Aura Microwave Limb Sounder stratospheric ozone profiles and Tropospheric Emission Monitoring Internet Service-Koninklijk Nederlands Meteorologisch Instituut climatological profiles to create a priori input files for spectral modeling. The MODTRAN4 estimates of ozone columns from the 2006 observations compare rather well with the OMI total ozone column data: standard errors are of 1.11 DU and 0.68 DU, standard deviation are of 8.77 DU and 5.37 DU for OMI DOAS and OMI Total Ozone Mapping Spectrometer, respectively. Copyright 2007 by the American Geophysical Union.