Satellite-derived Springtime Uv Climatology Over Europe: Months of March, April and May From 1984 To 2001
Abstract
The poster presents progress made in the building of a satellite-derived ultraviolet (UV) radiation climatology over Europe, covering the last 10 to 20 years. The method- ology to model the surface UV with satellite and ancillary geophysical data has been initially developed and evaluated during the European project MAUVE. The resulting products are maps of the surface dose rates and daily doses, covering Europe (12E- 32E, 34N-74N) with a spatial resolution of 0.05 deg. The method basically consists in using a standard radiative transfer code (UVspec) and in exploiting various sources of information to assign values to the influencing parameters. GOME, TOMS or TOVS data are used for the total column ozone. The attenuation of radiation by clouds is estimated using the MVIRI/METEOSAT visible channel data. In practice, for each METEOSAT pixel, a cloud liquid water path is derived from the enhancement of the signal with respect to the cloudless situation. Other influencing factors taken into ac- count include the tropospheric aerosols (using the observations by the ground mete- orological stations), the snow cover and the surface elevation. The paper presents the results for the months of March, April and May from 1984 to 2001. The generated data set is made of daily maps of near noontime dose rates from which daily and monthly doses are extrapolated. The maps are available for several action spectra: UVA, UVB, erythemal, SCUPh, DNA and PLANT. The variability of the UV radiation during the 18 years period, as deduced from this data set is illustrated. The year-to-year varia- tions are essentially due to changes in total column and cloudiness. These two factors are also documented separately. The validity of the results is discussed. Over such a period, the consistency of the input data and the impact on the modelled surface UV radiation is a critical issue for drawing conclusions on possible changes and trends. A partial validation of the results is demonstrated by comparison with ground UV measurements performed at Ispra, from 1992 to 2001.
- Publication:
-
EGS General Assembly Conference Abstracts
- Pub Date:
- 2002
- Bibcode:
- 2002EGSGA..27.4026V