Tropospheric ozone columns and ozone profiles for Kyiv in 2007

Abstract

We report on ground-based FTIR observations being performed within the framework of the ESA-NIVR-KNMI project 2907 entitled "OMI validation by ground based remote sensing: ozone columns and atmospheric profiles" for the purpose of OMI data validation. FTIR observations were performed during the time frames mostly under cloud free and clear sky conditions and in some days from early morning to sunset covering the full range of solar zenith angles possible. Ozone column and ozone profile data were obtained for the year 2005 using spectral modeling of the ozone spectral band profile near 9.6 microns with the MODTRAN3 band model based on the HITRAN-96 molecular absorption database. The total ozone column values retrieved from FTIR observations are biased low with respect to OMI-DOAS data by 8-10 DU on average, where they have a relatively small standard error of about 2%. FTIR observations for the year 2006 were simulated by MODTRAN4 modeling. For the retrieval of ozone column estimates and particularly ozone profiles from our FTIR observations, we used the following data sources to as input files to construct the (a priori ) information for the model: satellite Aqua-AIRS water vapor and temperature profiles; Aura-MLS stratospheric ozone profiles (version 1.5), TEMIS [4] climatological ozone profiles and the simultaneously performed surface ozone measurements. Ozone total columns obtained from our FTIR observations for year 2006 with MODTRAN4 modeling are matching rather well with OMI-TOMS and OMI-DOAS data where standard errors are 0.68% and 1.11%, respectively. AURA-MLS data of version 2.2 which have become available in 2007 allow us to retrieve tropospheric ozone profiles. For some days Aura-TES tropospheric profiles were also available and were compared with our retrieved profiles for validation. A preliminary analysis of troposphere ozone variability was performed. Observation during the time frame March-October demonstrate daily photochemical variability of tropospheric ozone and reveal mixing processes during the night.

Environmental monitoring of surface ozone and other trace gases over different time scales: chemistry, transport and modeling

“…O 3 is not emitted directly by any natural source, but is indeed formed through a set of photochemical reactions involving primary precursors [NO x , CO, volatile organic compounds (VOCs) etc.] under high solar radiation flux conditions (Shavrina et al 2010). These precursor gases are emitted directly from the agricultural fields and indirectly from oxidation of fossil fuels, biomass burning and anthropogenic activities (Swamy et al 2012a).…”

“…These models are useful tools for air pollution and climatic studies (Arteta and Cautenet 2007). Furthermore, these models help in the development of an environmental policy, in particular to GHGs emission on a local and regional scale (Shavrina et al 2010). But, forecasting air pollutant concentration is a difficult task due to complexity of physical and chemical processes involved.…”