On the 17th of November 2022, the first official review of the project with ESA was passed successfully. During this review, we presented a synthesis of the first workshop, and based on that, we elaborated a first version of the assessment framework.

This first approach is summarized in the diagram below.

The first held SIN’XS workshop together with members of the SAC, SB and other members of the sea-ice community showed the need for a robust protocol to assess different data sets, but also highlighted the various expectations towards the SIN’XS project results. Therefore, this first iteration will focus on a robust and minimalistic approach using community-provided datasets ‘as is’.

Both validation as well as the inter-comparison will be using a nearest-neighbour approach.

However, before registering a dataset to the SIN’XS database, a minimum requirement with regards to metadata and data format must be met. This includes the need for a dataset to be provided in the Network Common Data Format (CF 2.3.1) with a minimum of global attributes. The information will facilitate the inter-comparison of all received datasets.

Due to the fact that the majority of the currently identified SIT datasets either rely on satellite altimetry as their source of data acquisition or modelling, the dominant application-type category was identified as ‘climate studies’. From a processing level perspective, the SIN’XS database will require all input datasets to be on a Level 3 minimum, i.e., SIT/SD being mapped on a projection grid using the Lambert Azimuthal Equal Area based EASE2 grid, with some completeness and consistency as monthly summaries.

These minimum requirements will facilitate a fair comparison between products (SIT/SD-E in Figure 1) as well as between each product and the identified reference datasets. A memo describing all the requirements to submit a dataset to SIN’XS project will be published in the coming weeks.