Some characteristics of natural arctic hydroacoustic under ice noise

We compare recorded data from Gulf of Bothnia, a Swedish lake, Lake Hornavan, with data from Spitsbergen. The Lake Hornavan is the deepest lake in Sweden with a depth of up to 221 m. The recordings are from the spring in March 2014. During daytime, the ice is melting and during the afternoon and night, the ice is freezing, these are causing different noise characteristics. The Gulf of Bothnia data are from two BIAS1 recording positions at the Finnish part of the bay recorded during 2016. The Spitsbergen data comes from Hornsund fjord surrounded by mountains and melting glaciers. The main motivation with this paper is by data analysis perform characterization of natural noise sources through spectral and statistical features of the noise, with a particular emphasis on cracking, freezing and melting ice. The statistics shows large differences between melting and freezing ice noise sources. For the natural ice noise sources, the features can be used as a complement to conventional automatic identification and characterization of the natural ambient under ice noise environment.(1) EU-project Baltic Sea Information on the Acoustic Soundscape, BIAS LIFE11 ENV /SE 84