We present an experimental Automatic Identification System (AIS) receiver set-up to study anomalous signal propagation over coastal and marine waters in the northern Baltic Sea. Anomalous atmospheric conditions can allow for the AIS messages to be received from farther distances than under normal conditions. The results show that under anomalous conditions, the messages can be received up to 600 km away and have both diurnal and seasonal cycles.

We tracked sea ice deformation over a nine-month period using high-resolution ship radar data and a state-of-the-art deep learning technique. We observe that the typically consistent scale-invariant pattern in sea ice deformation has a lower limit of about 10² meters in winter, but this behavior disappears during summer. Our findings provide critical insights for considering current modeling assumptions and for connecting the scales of interest in sea ice dynamics.