Location of the study area. The larger box features Bothnian Bay (BB) bathymetry (Baltic Sea Hydrographic Commission, 2013, Baltic Sea Bathymetry Database version 0.9.3, downloaded from http://data.bshc.pro/ on 17 August 2016) with location of winter water sampling stations (red) and ice stations (black). Both the ICES and dBotnia database stations (measurements in Table 2) were used for model initialization after linear interpolation over the model domain. BS stands for Bothnian Sea. DOI: https://doi.org/10.1525/elementa.223.f1