High-Resolution Pan-Arctic Mapping of Multiyear and First-Year Sea Ice Using the RADARSAT Constellation Mission

Abstract

In this study, we derived pan-Arctic multiyear ice (MYI) and first-year sea ice (FYI) retrievals at 1.6 km resolution under no-melt conditions using the RADARSAT Constellation Mission (RCM) ScanSAR dual-polarization HH-HV synthetic aperture radar (SAR) data. The RCM products consistently provide fine-scale MYI/FYI details that are not resolved by low-resolution passive microwave (PM) observations. Verification of the RCM MYI/FYI products against the corresponding Canadian Ice Service (CIS) image analyses revealed that 60.28% of MYI/FYI image analysis samples were classified with a very high accuracy of 99.58% over 2020–2025. We also generated pan-Arctic RCM MYI/FYI gridded products at 2 km resolution aggregated over three- and seven-day rolling temporal windows from 2022 to the present. We found the RCM MYI/FYI products to be in good agreement with existing PM datasets. The proportion correct total (PCT) scores were 0.90 and 0.69 when compared against daily Ocean and Sea Ice Satellite Application Facility (OSI SAF) and weekly National Snow and Ice Data Center (NSIDC) products, respectively. The RCM high-resolution MYI/FYI retrievals are being assimilated in the Environment and Climate Change Canada (ECCC) ice type data assimilation system that efficiently combines them with low-resolution PM and scatterometer observations.