Lagrangian trajectory dataset used in Fiol et al. 2026

This dataset contains the Lagrangian trajectories used in Fiol et al. (2026). The folder 'IABP_data' contains some preprocessed files obtained with the script preprocess_seeding.ipynb (doi.org/10.5281/zenodo.17896832). There is a file per period, so 8 in total. These files contain the position (latitude and longitude) of the IABP buoys over time. Each buoy is identified with an ID. A mask is also given, telling for which instants the position of a given buoy is known (equal to 1 in this case and to 0 otherwise). The folder 'Seeding_files' contains the seeding files used in Fiol et al. (2026). These files could be directly used with sitrack tool (https://github.com/brodeau/sitrack) to seed and advect buoys. There is a file per period. Each file contains the ID of the buoys (corresponding to those of the IABP buoys), the seeding date and the position of the buoys. The seeding position is given in latitude and longitude and also on a Cartesian frame with x and y positions in kilometers. The rest of the dataset corresponds to trajectory files obtained using sitrack and the NEMO outputs used in Fiol et al. (2026). There is one folder per experiment: 6 experiments in total (3 with BBM rheology and different initial positional amplitudes of perturbation, and 3 with aEVP rheology and different positional amplitudes of perturbation). Each experiment folder contains one folder per period. At the end, each period folder contains a file per member, so 20 trajectory files in total. Each file contains the position of the virtual buoys over time. The positions are given in latitude and longitude and also on a Cartesian frame with x and y positions in kilometers. Each buoy is associated with an ID: it corresponds to that of the IABP buoy which is at the same position as the virtual buoy at the seeding instant. A mask is also given, telling for each instant if the virtual buoys are still alive (mask equal to 1), i.e., still in the pack ice (concentration of minimum 10%). Some variables are also given along the trajectory: sea ice concentration (siconc, no unit), sea ice thickness (sithic, m), module of atmospheric stress on sea ice (taum_ai, N/m2), module of oceanic stress on sea ice (taum_oce, N/m2), wind speed at 10 m (windsp, in m/s) and its components along NEMO x- and y-axes (uz1_abl and vz1_abl, m/s). The Cartesian frame mentioned above is obtained from the NorthPolarStereo projection of cartopy using latitude = 70 °N and longitude = -45 °E.