A year-round satellite sea-ice thickness record from CryoSat-2

Area of Science:

• Earth Science
• Climate Science
• Oceanography

Background:

• Arctic sea ice is diminishing at an unprecedented rate due to climate warming.
• Increased commercial interest in the Arctic due to receding ice raises maritime safety concerns.
• Current satellite observations lack sea-ice thickness data during the critical May-September melt period.

Purpose of the Study:

• To generate a pan-Arctic sea-ice thickness dataset for the Arctic melt period.
• To overcome challenges in processing CryoSat-2 radar altimetry data.
• To provide data for improved seasonal forecasting and understanding of Arctic climate feedbacks.

Main Methods:

• Utilized deep learning and numerical simulations of CryoSat-2 radar altimeter response.
• Generated a pan-Arctic sea-ice thickness dataset for the melt period (May-September).
• Validated data against independent sensors and Pan-Arctic Ice Ocean Modelling and Assimilation System reanalysis.

Main Results:

• Developed a novel method to process CryoSat-2 altimetry data for sea-ice thickness during melt.
• Quantified Arctic sea-ice thickness decline from 1.87 m in May to 0.82 m in August (2011-2020).
• CryoSat-2 data capture melt rates and align with modeled sea-ice volume.

Conclusions:

• The new year-round sea-ice thickness record enhances understanding of Arctic climate feedbacks.
• Early summer sea-ice volume data can extend the lead time of seasonal forecasts by months.
• Improved data availability supports safer Arctic maritime operations and seasonal forecasting.