A new actinic flux 4?-spectroradiometer: Instrument design and application to clear sky and broken cloud conditions - Archive ouverte HAL Accéder directement au contenu
Article Dans Une Revue Atmospheric Chemistry and Physics Discussions Année : 2002

A new actinic flux 4?-spectroradiometer: Instrument design and application to clear sky and broken cloud conditions

Résumé

A new 4p-spectroradiometer was developed for measuring actinic flux especially under cloudy conditions based on a fixed grating imaging spectrograph and a CCD-detector leading to a simultaneous measurement of the spectrum. The new instrument incorporates a novel optical head with a 4p-field of view independent of angle of incidence. Comparisons with the actinic flux spectroradiometer of the Institute of Atmospheric Chemistry of Forschungszentrum Jülich showed a very good agreement within the limit of the uncertainties of the two instruments. Our spectroradiometer was applied to investigate the effects of broken clouds on the actinic flux and photolysis frequencies on the ground during the BERLIOZ campaign. Reductions as well as enhancements compared to the clear sky case were seen, both effects are larger in the UV-A than the UV-B spectral region.
Furthermore the new instrument was used for simultaneous measurements in different altitudes on a tower to study the transmission and attenuation of actinic flux in low clouds. A correlation of attenuation with the simultaneously measured liquid water content of the cloud was found.
Fichier principal
Vignette du fichier
acpd-2-1939-2002.pdf (837.48 Ko) Télécharger le fichier
Origine : Accord explicite pour ce dépôt
Loading...

Dates et versions

hal-00300969 , version 1 (18-06-2008)

Identifiants

  • HAL Id : hal-00300969 , version 1

Citer

E. Eckstein, D. Perner, Ch. Brühl, T. Trautmann. A new actinic flux 4?-spectroradiometer: Instrument design and application to clear sky and broken cloud conditions. Atmospheric Chemistry and Physics Discussions, 2002, 2 (6), pp.1939-1977. ⟨hal-00300969⟩

Collections

INSU EGU
49 Consultations
35 Téléchargements

Partager

Gmail Facebook X LinkedIn More