Reference data package supports evaluation of sea ice altimetry

What the study found: The study presents a repurposed collection of sea ice reference measurements for comparing with satellite altimetry products. It includes measurements of freeboard, thickness, draft, and snow depth from both hemispheres and is matched to monthly satellite altimetry time-space scales.
Why the authors say this matters: The authors say sea ice altimetry estimates need quality control against reference measurements, and that this data package can support direct evaluation of satellite-derived sea ice thickness products. They also present the dataset as a validation source with described averaging, collocation, and uncertainty methods.
What the researchers tested: The researchers assembled a Climate Change Initiative (CCI) Sea Ice Thickness Round Robin Data Package from multiple sources, including airborne sensors, drifting buoys, upward-looking sonars on moorings and submarines, and visual observations. They prepared it for 25 km Northern Hemisphere and 50 km Southern Hemisphere spatial resolution and monthly temporal resolution to match conventional satellite altimetry products, and collocated it with CryoSat-2, Envisat, and ERS-1/2 products.
What worked and what didn't: The abstract says the package was used to demonstrate overlap and inter-comparison between reference measurements and satellite-derived products. It also notes that the code is publicly available and can be modified by users, and that the dataset covers the polar satellite altimetry era from 1993 to 2024; advantages and limitations are discussed, but no specific performance outcomes are stated in the abstract.
What to keep in mind: The abstract does not give detailed numerical validation results or specific conclusions about which satellite product performed better or worse. It also says the dataset is still being updated, so the current version is not necessarily final.

Key points

• The study introduces a sea ice reference measurement data package for evaluating satellite altimetry products.
• The package includes freeboard, thickness, draft, and snow depth measurements from both hemispheres.
• It is matched to monthly satellite product scales, with 25 km resolution for the Northern Hemisphere and 50 km for the Southern Hemisphere.
• The data package was collocated with CryoSat-2, Envisat, and ERS-1/2 sea ice thickness products.
• The abstract says the dataset spans the polar satellite altimetry era from 1993 to 2024 and is still being updated.