Linking timescale-dependent Antarctic sea ice kinematic observations to ice thickness

Sea ice kinematics impacts the global ocean-atmosphere system in numerous ways: modification of albedo, ice cover, and ice mass; heat transmission between atmosphere and ocean; and ice thickness distribution. Such research is often conducted using in situ and remotely-sensed observations of ice motion. In recent work, an ice motion product generated from overlapping sections of multiple individual swath pairs - the so-called swath-to-swath (S2S) approach - has been favourably evaluated by buoys in the Arctic. This new product better able to represent drifting buoy trajectories, however, it has yet to be applied to ice kinematics research. In this study, we investigate the Antarctic sea ice differential kinematic parameters (DKPs) represented by divergence and maximum shear rate computed from the new S2S ice motion product, and compare these with the daily-map (DM)-derived DKP magnitudes. Results indicate that S2S-derived DKP magnitudes are highly timescale-dependent and well represented by an exponential relationship. Furthermore, the exponential DKP curve parameters in this work are shown to correspond well to ice thickness, thus enabling a new class of Antarctic ice thickness proxy observations. This technique lays the groundwork for the possibility of new proxy measurement of ice thickness back to at least 1991, when the high-accuracy S2S measurements of ice motion become available.

Automated summary

Sea ice kinematics has significant impacts on the global ocean-atmosphere system, affecting albedo, ice cover, heat transmission, and ice thickness distribution. A new ice motion product called S2S shows promise in representing ice drift trajectories, but its application in ice kinematics research is yet to be explored. This study investigates Antarctic sea ice differential kinematic parameters using the S2S ice motion product and compares them with parameters derived from daily maps. The results indicate a strong correlation between S2S-derived parameters and time scale, as well as a relationship with ice thickness, suggesting the potential for proxy measurements of ice thickness.