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Ann. Geophys., 24, 7-21, 2006
www.ann-geophys.net/24/7/2006/
© European Geosciences Union 2006
Measurements of spectral snow albedo at Neumayer, Antarctica
S. Wuttke1,*, G. Seckmeyer1, and G. König-Langlo2
1Institute for Meteorology and Climatology, University of Hannover, Herrenhäuser Str. 2, 30419 Hannover, Germany
2Alfred-Wegener-Institut für Polar- und Meeresforschung, Institute for Polar and Marine Research, Bussestr. 24, 27570 Bremerhaven, Germany
*now at: Alfred-Wegener-Institut für Polar- und Meeresforschung, Institute for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany
Abstract. Spectral albedo in high resolution, from 290 to 1050 nm, has been
measured at Neumayer, Antarctica, (70°39' S, 8°15' W)
during the austral summer 2003/2004. At 500 nm, the spectral albedo
nearly reaches unity, with slightly lower values below and above
500 nm. Above 600 nm, the spectral albedo decreases to values
between 0.45 and 0.75 at 1000 nm. For one cloudless case an albedo up
to 1.01 at 500 nm could be determined. This can be explained by the
larger directional component of the snow reflectivity for direct incidence,
combined with a slightly mislevelled sensor and the snow surface not being
perfectly horizontal. A possible explanation for an observed decline in
albedo is an increase in snow grain size. The theoretically predicted
increase in albedo with increasing solar zenith angle (SZA) could not be
observed. This is explained by the small range of SZA during albedo
measurements, combined with the effect of changing snow conditions outweighing
the effect of changing SZA. The measured spectral albedo serves as input for
radiative transfer models, describing radiation conditions in Antarctica.
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