TY  - JOUR
A1  - Becker, Ralf
A1  - Maturilli, Marion
A1  - Philipona, Rolf
A1  - Behrens, Klaus
T1  - In situ sounding of radiative flux profiles through the Arctic lower troposphere
Y1  - 2020-05-15
VL  - 1
IS  - 2
SP  - 155
EP  - 177
JF  - Bulletin of Atmospheric Science and Technology
DO  - 10.1007/s42865-020-00011-8
PB  - Springer International Publishing
N2  - In situ profiles and fixed-altitude time series of all four components of net radiation were obtained at Ny-Ålesund, Svalbard (78.9° N, 11.9° E), in the period May 04–21, 2015. Measurements were performed using adapted high-quality instrumentation classified as “secondary standard” carried by a tethered balloon system. Balloon-lifted measurements of albedo under clear-sky conditions demonstrate the local dependence on altitude and on the surface inhomogeneity of this parameter over coastal terrain of Ny-Ålesund. Depending on the surface composition within the sensor’s footprint near the coastline, the albedo over predominantly snow-covered surfaces was found to decrease to 0.548 and 0.452 at 494 m and 881 m altitude compared with 0.731 and 0.788 measured with near-surface references, respectively. Albedo profiles show an all-sky maximum at 150 m above surface level due to local surface inhomogeneity, and an averaged vertical change rate of − 0.040/100 up to 750 m aboveground level (clear sky) and − 0.034/100 m (overcast). Profiling of arctic low-level clouds reveals distinct vertical gradients in all radiative fluxes but longwave upward at the cloud top. Observed radiative cooling at the top of a partly dissolving stratus cloud with heating rates of − 40.4 to − 62.1 Kd−1 in subsequent observations is exemplified.
UR  - http://resolver.sub.uni-goettingen.de/purl?gldocs-11858/10568
ER  -