TY  - JOUR
AU  - Hofzumahaus, A.
AU  - Kraus, A.
AU  - Kylling, A.
AU  - Zerefos, C. S.
TI  - Solar actinic radiation (280-420 nm) in the cloud-free troposphere between ground and 12 km altitude : measurements and model results
JO  - Journal of geophysical research / Atmospheres
VL  - 107
SN  - 0022-1406
CY  - Washington, DC
PB  - Union
M1  - PreJuSER-33390
SP  - PAU 6-1 - 6-6
PY  - 2002
N1  - Record converted from VDB: 12.11.2012
AB  - [1] Airborne measurements of the spectrally resolved actinic flux (280-420 nm) between the ground and 12 km altitude have been made using a new calibrated dual-channel spectroradiometer. The measurements were made as part of the Photochemical Activity and Ultraviolet Radiation/Altitude Dependence of the Tropospheric Ozone Photolysis (PAUR/ATOP) measurement campaign in Greece during June 1996. Flights were made over the Agean Sea under cloudless conditions for various aerosol loads and solar zenith angles. The spectral actinic flux measurements are compared with radiative transfer model simulations based on the multistream discrete ordinate radiative transfer (DISORT) algorithm. All input to the radiative transfer model was provided by independent measurements performed simultaneously on the nearby island of Agios Efstratios. For altitudes between 3000-12,000 m the agreement between the measurements and the model simulations is within +/-5% for wavelengths larger than 310 nm and within +/-10% at 295-310 nm. For the lowest flight altitude, 108 m, the model underestimates the measured actinic flux systematically by about 12%. This may be partly explained by uncertainties in the aerosol optical properties and the surface albedo. Flights on days with small and large amounts of aerosols showed that under otherwise identical conditions the actinic flux increased by up to 10% when the aerosol amount was larger.
KW  - J (WoSType)
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000180427400007
DO  - DOI:10.1029/2001JD900142
UR  - https://juser.fz-juelich.de/record/33390
ER  -