Image Gallery
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Figure 1: GOME SO2 total columns above Europe averaged over the
period 15-29 February 1996. Enhanced SO2 levels observed in Eastern
Europe are most likely emissions from coal power plants. During this
period surface temperatures were extremely low so that private
household may also have contributed to the high SO2 values (Eisinger
and Burrows, 1999)
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Figure 2: GOME time series of mean Arctic vortex ozone
volume mixing ratios on the 475 K isentropic potential temperature
surface (about 19 km altitude) during Arctic winter/spring season
1996/97. Solid points are the GOME results and error bars are the
1sigma standard deviations from averaging inside the polar vortex. The
solid line represents the ozone time series, where the subsidence of
the vortex has been calculated from diabatic heating rates and the
accumulated diabatic ozone changes (bottom plot) were subtracted from
the original times series. This curve provides an estimate of the true
chemical ozone loss during the course of the winter. Between middle of
February and early May 1997 an accumulated ozone loss of 52% have been
derived (Bramstedt et al. 2000). For more information on ozone profile
retrieval contact Kai-Uwe
Eichmann.
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Figure 3: Mean surface UV index in January 1998 derived from
GOME data. Radiative transfer calculations using the total ozone
information from GOME determines the clear-sky surface UV flux. Cloud
information are derived from estimation of the Lambertian equivalent
reflectivitity (LER), which is defined as the surface albedo in an
aerosol and cloud free atmosphere that provides the appropiate
top-of-atmosphere radiance observed by GOME. High LER are indicative
of the presence of clouds and the LER values are used to estimate the
cloud attenuation of the UV surface flux. The UV index is an
erythemally weighted integrated surface flux (Erythema=sun burn) and
is normally calculated for local noon time (maximum exposure)
condition.
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Figure 4: Formaldehyde annual mean vertical columns from
GOME in 1998. High amounts of HCHO have been observed in
particular above rain forests in equatorial regions. They are probably
due to high biogenic emissions of terpenes and isoprenes. Further
information about HCHO evaluation is available on the IUP DOAS page) or please contact Folkard Wittrock.
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Figure 5: March northern hemispheric total ozone
distributions 1996-2000 (from left to right and top to bottom) and
climatogical mean from Nimbus7/TOMS 1979-1993 (bottom right).
After extended periods of very low stratospheric temperatures in the
polar region during winter, low total ozone columns were observed in
March (1996, 1997, and 2000). The mean position of the
polar vortex, a stratospheric cyclone, where low ozone was measured is
indicated by the dashed contour. High total ozone values throughout the
northern hemisphere (NH) were found following winters with warmer
stratospheric temperatures (1998 and 1999). The Arctic stratospheric
winter/spring seasons exhibit high interannual dynamic variability in
meteorology and ozone and leads to very different levels of chemical
ozone depletion each year. The Greenwich meridian (0ºE) points
towards the bottom in the stereographic projection.
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