A monthly 5 km Arctic sea ice thickness product from 1995 to 2023 using multiple radar altimetry data

Arctic sea ice is of great importance to the regional and global climate change study. Satellite observations have demonstrated that the Arctic sea ice extent has been declined for the last four decades. However, long-term variations of the Arctic sea ice thickness (SIT) are less focused as SIT cannot be measured directly by satellite-based instruments. Here, we presented a monthly Arctic SIT product based on multiple radar altimetry observations from ERS-2, Envisat, and CryoSat-2. To ensure the accuracy of the SIT retrievals, we proposed a novel data processing procedure including leads detection, freeboard conversion to thickness and inter-mission bias correction. Finally, we were able to generate the monthly SIT estimates for the Arctic Ocean from October 1995 to December 2023. The thickness estimates are posted on a 5 km resolution polar stereographic grid. The variations of the Arctic SIT are analyzed in terms of the spatial and temporal distributions. We also compared our SIT estimates with observations from upward looking sonars (ULSs) and airborne laser altimetry from Operation IceBridge (OIB), as well as seven publicly released Arctic SIT products. The validation results demonstrate that our SIT product features equivalent accuracy with existing products. The accuracy of our products is about 0.4 m during Envisat period, and is within 0.2 m during CryoSat-2 period.