Radiation Measurements

Spectral and integral radiation quantities can be determined with a number of instruments under field- and laboratory conditions. At the ICE-3, measurements of actinic radiation, meteorological broadband measurements and the use of a sun photometer are carried out.

Actinic radiation

Actinic radiation measurements to determine photolysis frequencies have been made since many years at ICE-3. Absolutely calibrated spectral radiometers and filter radiometers are used for that purpose. These instruments are deployed for ground based field measurements, for experiments in the atmosphere simulation chamber SAPHIR, and on mobile platforms like the Zeppelin-NT and the research aircraft HALO. In addition, the spectral radiometers serve as a reference for instruments of other institutions. A roof platform with subjacent laboratory is available for such comparisons under field conditions, as well as calibration facilities. Moreover, measurements can be made to characterise photochemical laboratory reactors and simulation chambers.

Meteorological broad-band measurements

Pyranometers, pyrgeometers and pyrheliometers for the determination of solar and terrestrial radiation flux densities are operated to support the continuous JOYCE observations. The instruments are installed on a suntracker to distinguish between direct and diffuse solar radiation. In addition, the suntracker can be applied for the determination of spectral radiation quantities (actinic radiation).

Sun photometer

Since 2012 a sun photometer is operated that determines wavelength dependent aerosol optical depths and the amount of precipitable water vapour. The instrument is part of the world-wide AERONET network and also provides important data for the retrieval of cloud optical depths under overcast conditions.