[Study on the basic characteristics of Bohai Sea ice reflectance spectra]

For monitoring sea ice in Bohai Sea, the present paper performed a field observation experiment on sea ice reflectance spectrum in Bohai Sea by control experiment. In the experiment, three groups of sea ice samples from the Bayuquan in Liaodong Gulf were collected, which were clean even ice of different thickness, sea ice covered by melt snow layer and sea ice with sands. According to the series of observation data during the two years, the reflectance spectrum curve of clean even ice has double peaks (a big one and a small one) when the ice thickness is less than 30 cm. The principal reflection peak is in good relation to the thickness of the sea ice. The principal reflection spectral peak of ice covered by melt snow layer is obviously higher than that of the spectrum of clean even ice without the snow layer with the same ice thickness. The principal reflection spectral peak of the sea ice with sands increases sharply, and the spectrum curve arises slightly in the wavelength rang between 675 and 725 mm and then declines. Covering snow and sands are the key factors to result in the fact that the same ice thicknesses present different spectrum characteristics and the same spectrum characteristics present different thicknesses.