Method for Prediction of Sea Ice Thickness Based on the Blowing Air Temperature and Speed

Abstract

Maritime traffic with ice breaking vessels as well as offshore activities in polar regions depend a lot on the freezing of the sea water; hence the importance of the sea ice determination, i.e. its thickness and its distribution over the sea area. This work studies the problem of the ice thickness determination. Generally, some information about sea ice thickness is provided by remote sensing data or from climatological models for large arctic regions. However, these data are not so accurate. Due to the lack of existing reliable measured data, the ice thickness must be often estimated. Various methods and models are able to predict the ice thickness to a certain extent. Some are empirical, but the most physically reliable are rather based on thermodynamic processes that occur during the ice growth. Nevertheless, some environmental conditions, such as snowfall, solar radiation, different heat fluxes coming from the atmosphere, the sea, salinity etc. complicate a lot the sea ice formation processes making equations difficult to be solved. This Master Thesis presents a thermodynamical approach of the ice growth based on the blowing air characteristics, more precisely its temperature and speed. The model is rather constructed for first-year ice. Some physical phenomena such as snowfall and the interaction between the water and the surrounding environment has been taken into consideration. Unlike other climatological models, this model treats the salinity distribution over the depth of the ice sheet, using more recent and well adapted data. The different heat transfer equations between the water, the ice, the snow if any and the atmosphere are solved numerically using finite differences methods. A simple forward differencing scheme has been applied with adequate space and time steps to provide stable solutions. The results found with the above theoretical approaches have been compared with the ones found during the experiments that have been performed in the ice facilities of the Hamburg Ship Model Basin (HSVA). Some conclusions comprised of results discussion and propositions are presented as well for any further studies.