hyperspectral albedo data collected at Ny Alesund

The produced dataset (in csv format) contains snow spectral albedo as measured the field activity carried out in Ny-Alesund (Svalbard Islands, Norway), where an unmanned apparatus was installed to provide continuous observations during the 2014 spring/summer period at the CNR Climate Change Tower, with the aim to deeply investigate changes in radiative characteristics during snow melting process. The survey covered the period from 25 May to 9 July 2014, when weather is highly variable and the Sun is constantly above the horizon. The continuous monitoring of the spectral albedo of the snowed surface was obtained coupling a tilting system with an ASD FieldSpec 3 portable spectroradiometer. The system was installed during the boreal spring nearly 8 m above the ground. The foreoptic applied to the fiber was a remote cosine receiver (RCR) with an hemispheric field of view that was fixed on the tilting device. The collected radiant energy was detected by the three spectroradiometers included in the Fieldspec with a wavelength range comprised between 350 and 2500 nm with a maximum spectral resolution of 1 nm. The spectral albedo measurements were acquired using the standard RCR mounted on the tilting system. Measurement cycles were performed every 15 min. Dark and optimization operations were executed every hours to estimate gain and spectral offset for each radiometer. Each rotation cycle was composed by a sequence of six downwelling irradiance spectra performed before and after three upwelling measurements, by completing the whole sequence in less than 3 min. All the stored spectra result from the average of ten fast acquisitions. Standard deviation associated to each triplet of spectra, provided information on sky stability, hence, indicating the possibility to perform accurate determination of the spectral albedo. For more details on experimental setup, acquisition and analysis procedures please refers to Salzano R., Lanconelli C., Salvatori R., Esposito G., Vitale V. (2016), Continuous monitoring of spectral albedo of snowed surfaces in Ny-Alesund, Rend. Fis. Acc. Lincei, 27 (Suppl 1):S137–S146 doi: 10.1007/s12210-016-0513-y Data set include 1728 spectra of snow albedo with a resolution of 1 nm from 350 nm to 2500 nm. They are stored in a unique file that contains columns of collected measurements in the following order: row 1 wavelenght channels (w_350, w_351, .........w_2500); Time from row 2 column 1 Spectra number (albedo, alb, alb.1.....alb.1726) column 2 snow spectral albedo at 350 nm ...... column 2501 snow spectral albedo at 2500 nm column 2502 Date time (AAAA-MM-DD HH:MM) in UTC We have holes in the data, mainly due to instrument failures