Breaks in the Arctic ice cover: from observations to predictions

Abstract

Breaks (ruptures) and cracks is the distinguishing feature of any ice cover in the Arctic seas during the cold season and in the whole Arctic Basin throughout a year. The formation of them is a consequence of macro-deformation of the ice thickness. Investigating of the ice breaking in the Arctic begins with single visual observations during the ice aerial surveys in the 1940s and continues till nowadays using regular information from artificial Earth satellites. Processing of big volumes of satellite data and creating climatological datasets on breaks became possible owing to the development of algorithms for automatic identification of the ice breaks in images. Interpretation of the satellite images is based on the fundamental difference between physical properties of breaks and the surrounding consolidated ice. Algorithms for automatic recognition of ruptures using satellite data obtained in different wavelength ranges, including the use of artificial intelligence, are currently being developed. The main characteristics of breaks which are usually analyzed are as follows: the summarized area of them and its ratio to the total area of the ice field, the mean and maximum widths as well as the total length. The temporal and spatial variability of these characteristics is also considered. Such information is needed for solving problems of improving models of ice cover dynamics and modeling the interaction between the ocean and the atmosphere at high latitudes. A specific feature of publications of the Russian authors on this topic is the practical use of the results obtained for hydrometeorological support of navigation in ice. For the navigation purposes, the dominant orientation of the ruptures on the way of ships is of greatest importance. Operational and prognostic information about the orientation and extent of ruptures, including distribution of them in an ice field are the key data for choosing the optimal sailing route in the Arctic.