Drivers of interannual variations of ice age composition in sub-areas of the Barents Sea

Abstract

The present study deals with assessing the impact of the factors that define the interannual variations of ice area of different age categories in the Barents Sea. For the analysis, a set of hydrometeorological and ice parameters was created, potentially influencing the age composition of the sea ice cover. Among these are the climate indices of the Arctic Oscillation, the Arctic Dipole, the Pacific-North American Oscillation, the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation, as well as the surface air temperature, the ice cover in the previous months and the ice outflow on the sea ice in the Barents Sea. Based on the parameters above, statistical equations with high quality indicators have been obtained.The statistical equations are presented for the period of maximum ice cover in April. The results are provided for three homogeneous sub-areas of the Barents Sea: western, northeastern and southeastern. It is found that the atmospheric circulation pattern is the driver of the interannual variations in the Barents Sea ice age composition. The ice amount of different age categories is also determined by the advection of warm Atlantic Waters, but to a lesser extent; this effect is especially pronounced in the western sub-area of the Barents Sea. Essentially, the contribution of the local parameters, such as the ice cover in the previous months, the distribution of surface air temperature and the sea ice outflow, is more pronounced in the interannual variations of the ice coverage, while the contribution of climate indices is more pronounced in the changes in the ice area of individual age categories in the Barents Sea.Most of the models obtained are potentially applicable to forecasting the ice area of various age categories since their efficiency is more than 10 %, which satisfies the requirements for the quality of the long-term forecast method.