Retrievals of Arctic Sea-Ice Volume and Its Trend Significantly Affected by Interannual Snow Variability

• Published in: Geophysical Research Letters
• Main Authors: Bunzel, Felix, Notz, Dirk, Pedersen, Leif Toudal
• Language: unknown
• Published: 2022
• Subjects: 54 ENVIRONMENTAL SCIENCES; Arctic; Sea ice
• Online Access: http://www.osti.gov/servlets/purl/1544162; https://www.osti.gov/biblio/1544162; https://doi.org/10.1029/2018GL078867

We estimate the uncertainty of satellite-retrieved Arctic sea-ice thickness, sea-ice volume, and their trends stemming from the lack of reliable snow-thickness observations. To illustrate, we simulate a Cryosat2-type ice-thickness retrieval in an ocean-model simulation forced by atmospheric reanalysis, pretending that only freeboard is known as model output. We then convert freeboard to sea-ice thickness using different snow climatologies and compare the resulting sea-ice thickness retrievals to each other and to the real sea-ice thickness of the reanalysis-forced simulation. We postulate that different snow climatologies cause significant differences in the obtained ice thickness and ice volume. Moreover, we show that Arctic ice-volume trends derived from ice-thickness retrievals using any snow-depth climatology are highly unreliable because the estimated trend in ice volume can strongly be influenced by the neglected interannual variability in snow volume.