SIN'XS: The Sea Ice thickness INtercomparison eXerciSe
The SIN'XS project aims at a large-scale assessment of sea-ice and, to a lesser extent, snow thickness products. The thickness of sea ice is a key player in the polar climate system (see https://www.meereisportal.de/en/learn-more). It has been measured by space-borne altimeters since the mid-90s (see https://www.meereisportal.de/en/learn-more/sea-ice-measuring-methods for a comprehensive overview on the methods to measure sea-ice properties). Since 2010, there has been a rapid increase of available sea-ice thickness products thanks to the advent of new satellite missions. Data from other satellite missions and computer models are also considered. Despite the abundance of products, a large-scale assessment of how far they (dis-)agree is missing so far. This assessment is the key goal of the SIN'XS project, funded by the European Space Agency (ESA).
The main goals of the project are:
- Compiling a database of sea-ice and snow thickness products, comprising large-scale satellite or model-based products as well as in-situ data from airborne and upward-looking sonar data
- Defining an assessment framework for a consistent comparison
- Implementing a Graphical User Interface (GUI) for interactive analysis, comparison and download of the data
- Deriving a reconciled estimate of sea-ice thickness based on the products provided by the community
AWI leads the scientific part of the project: We, together with LEGOS and UCL, are responsible for identifiying the relevant datasets, contacting the data providers and coordinating the submission process. Together with LEGOS and UCL, we developed a framework for the assessment: All data are provided as netCDF files with monthly means in the EASE2 projection, a specified grid spacing (25 km), a consistent geographical extent and a common set of metadata. We lead the analysis of the submitted data. This encompasses a cross-product comparison between both large-scale and reference data, an assessment of the uncertainties and the development of a reconciled estimate of sea-ice thickness.
To date (January 28, 2025); 33 distinct datasets have been provided. This amounts to a total of 6810 files with monthly-mean sea-ice thickness, snow thickness or radar freeboard fields. The following Figure provides an overview:
Overview on the temporal availability of SIN'XS datasets for the northern and southern hemisphere. The product's name as it appears in the SIN'XS database is given on the y-axis. The names include an acronym for the provided quantity (SIT: Sea-Ice Thickness; SNT: Snow Thickness; RFB: Radar Freeboard), the hemisphere, the sensor's/model's name and the data provider. The line colors denote SIT, SNT and RFB datasets. Products are split up by category, according to the underlying measurement principle.
Contact
Outcomes
- Graphical User Interface: https://sinxs-tools.noveltis.fr/visualize-data
- Data Download: https://sinxs-tools.noveltis.fr/access-data
- Software Tools for Data Analysis: https://sinxs-tools.noveltis.fr/data_tools/
- Forum for Discussion of Results and Question: https://sinxs-gitlab.noveltis.fr/sinxs/forum
- A Data Paper describing the SIN'XS database and assessment framework is close to submission
Project partners
- NOVELTIS (Toulouse, France): Implementation of GUI, project management
- LEGOS (Toulouse, France): Scientific Advisors
- UCL (London, UK): Scientific Advisors