Global Ozone Monitoring Experiment (GOME) (Burrows et al., 1997)
measures the backscattered and reflected solar radiation from the
Earth's atmosphere and surface. The primary objective of GOME is the
determination of the global distribution of total ozone, total column
amounts of relevant atmospheric trace constituents, for instance,
O
, BrO, OClO, NO
, HCHO, and SO. Column amounts are retrieved using the differential
optical absorption spectroscopy method (DOAS) (Burrows et
al. 1993). However, total O and NO
columns are currently the only trace gases available as GOME level-2
data products (ESA, 1995).
From the broad spectral range (240 - 790 nm) at moderate spectral resolution (0.2 - 0.4 nm), height-resolved ozone information can be derived from the Hartley-Huggins ozone band in the shortwave region of GOME. The Full Retrieval Method (FURM) hoogen:98, which derives ozone profiles from the GOME sun normalized spectra, consists of two parts: a forward model, which is a pseudo-spherical multiple scattering radiative transfer model (RTM) GOMETRAN (Rozanov et al., 1997) calculating the top of atmosphere (TOA) radiance for a given state of the atmosphere as defined by the ozone vertical distribution, trace gas distribution, surface albedo, aerosol scenario among others, and an inversion scheme which matches in iterative steps the calculated TOA radiance to the measured GOME radiance by adjusting the model atmospheric parameters such as the vertical ozone distribution using appropriate weighting functions as provided by GOMETRAN. A detailed account on the retrieval methodology applied to GOME is given in the companion paper by Hoogen et al. (1998).