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| Titel |
A note on the interannual variations of UV-B erythemal doses and solar irradiance from ground-based and satellite observations |
| VerfasserIn |
C. Zerefos, D. Balis, M. Tzortziou, A. Bais, K. Tourpali, C. Meleti, G. Bernhard, J. Herman |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
0992-7689
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| Digitales Dokument |
URL |
| Erschienen |
In: Annales Geophysicae ; 19, no. 1 ; Nr. 19, no. 1, S.115-120 |
| Datensatznummer |
250014181
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| Publikation (Nr.) |
 copernicus.org/angeo-19-115-2001.pdf |
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| Zusammenfassung |
This study examines three
UV-B data sets: ground-based long-term spectral records at Thessaloniki, Greece
(40.5° N, 22.9° E) and San Diego, California, USA (32.7° N, 117.2° W) as
well as a global data set of daily erythemal dose obtained from the Total Ozone
Mapping Spectrometer (TOMS) onboard the Nimbus-7 satellite. Both ground-based
stations have long enough records of spectral UV-B measurements to allow
independent time series analyses. For 63° solar zenith angle (SZA) and clear
sky conditions the quasi biennial oscillation (QBO) effect in solar irradiance
at 305nm E305 is about 32% of the annual cycle for both San Diego and
Thessaloniki. The effect slightly increases with cloud cover of up to 4/8, and
decreases thereafter for cloud cover greater than 4/8. The data reveal that
cloudiness can-not offset interannual signals in UV-B records. The observations
at San Diego provide an independent confirmation of the widespread nature of the
QBO in UV-B, which about coincides in amplitude at the two station studies, both
located in the latitude zone 30°– 40° N. The peak-to-peak amplitude of the
QBO in erythemal dose derived from TOMS/Nimbus-7 data is 6.5% at Thessaloniki.
This is similar to the values calculated from ground-based measurements from
this station. Based on satellite data, we find that the amplitude of the QBO in
the erythemal dose is almost 40% of the amplitude of the annual cycle only in
the tropics. The ratio of the amplitudes of the QBO over the annual cycle in
erythemal dose decreases towards the extratropics, becoming less than 5% over
middle latitudes.
Key words. Atmospheric composition and structure
(geo-chemical cycles; transmission and scattering of radiation) |
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