TY - JOUR
T1 - Optical properties of mixed phase boundary layer clouds observed from a tethered balloon platform in the Arctic
AU - Sikand, M.
AU - Koskulics, J.
AU - Stamnes, K.
AU - Hamre, B.
AU - Stamnes, J. J.
AU - Lawson, R. P.
PY - 2010/8
Y1 - 2010/8
N2 - A tethered balloon system was used to collect data on radiometric and cloud microphysical properties for mixed phase boundary layer clouds, consisting of ice crystals and liquid water droplets during a May-June 2008 experimental campaign in Ny-lesund, Norway, located high in the Arctic at 78.9°N, 11.9°E. The balloon instrumentation was controlled and powered from the ground making it possible to fly for long durations and to profile clouds vertically in a systematic manner. We use a radiative transfer model to analyze the radiometric measurements and estimate the optical properties of mixed-phase clouds. The results demonstrate the ability of instruments deployed on a tethered balloon to provide information about optical properties of mixed-phase clouds in the Arctic. Our radiative transfer simulations show that cloud layering has little impact on the total downward irradiance measured at the ground as long as the total optical depth remains unchanged. In contrast, the mean intensity measured by an instrument deployed on a balloon depends on the vertical cloud structure and is thus sensitive to the altitude of the balloon. We use the total downward irradiance measured by a ground-based radiometer to estimate the total optical depth and the mean intensity measured at the balloon to estimate the vertical structure of the cloud optical depth.
AB - A tethered balloon system was used to collect data on radiometric and cloud microphysical properties for mixed phase boundary layer clouds, consisting of ice crystals and liquid water droplets during a May-June 2008 experimental campaign in Ny-lesund, Norway, located high in the Arctic at 78.9°N, 11.9°E. The balloon instrumentation was controlled and powered from the ground making it possible to fly for long durations and to profile clouds vertically in a systematic manner. We use a radiative transfer model to analyze the radiometric measurements and estimate the optical properties of mixed-phase clouds. The results demonstrate the ability of instruments deployed on a tethered balloon to provide information about optical properties of mixed-phase clouds in the Arctic. Our radiative transfer simulations show that cloud layering has little impact on the total downward irradiance measured at the ground as long as the total optical depth remains unchanged. In contrast, the mean intensity measured by an instrument deployed on a balloon depends on the vertical cloud structure and is thus sensitive to the altitude of the balloon. We use the total downward irradiance measured by a ground-based radiometer to estimate the total optical depth and the mean intensity measured at the balloon to estimate the vertical structure of the cloud optical depth.
KW - DISORT
KW - Mixed-phase clouds
KW - Radiative transfer
KW - Snow
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U2 - 10.1016/j.jqsrt.2010.03.002
DO - 10.1016/j.jqsrt.2010.03.002
M3 - Article
AN - SCOPUS:77953695352
SN - 0022-4073
VL - 111
SP - 1921
EP - 1930
JO - Journal of Quantitative Spectroscopy and Radiative Transfer
JF - Journal of Quantitative Spectroscopy and Radiative Transfer
IS - 12-13
ER -