Sea Ice Drift Forecast Experiment (2017-2020)

The Sea Ice Drift Forecast Experiment (SIDFEx, 2017–2020) is a community effort to collect and analyse Arctic sea ice drift forecasts at lead times from days to a year, based on arbitrary methods, for a number of sea-ice buoys and, ultimately, research icebreaker Polarstern, on a regular basis.


SIDFEx is motivated in part by the need to determine an optimal deployment position of the research icebreaker Polarstern when she will start her year-long drift across the Arctic in autumn 2019 (Multidisciplinary drifting Observatory for the Study of Arctic Climate – MOSAiC; Specifically, it is unclear whether forecast systems that account for initial conditions and provide forecasts of the evolving atmosphere, ice, and ocean system, can provide additional skill over drift forecasts made using historical sea-ice velocity fields. The MOSAiC drift provides a template for assessing the capabilities to forecast sea-ice drift for a range of applications, ranging from logistics support for future field experiments to potential search and rescue operations. The examination of sea-ice drift forecasts provides an integrated assessment of many aspects of the coupled atmosphere-ice-ocean system and will motivate in depth investigations into how key variables are measured, modelled, and forecast. In particular, we expect coordinated drift forecasts to draw attention to the interaction between sea-ice physics and boundary layer physics in both atmosphere and ocean. We expect that a systematic assessment of real drift forecasting capabilities will improve our physical understanding of sea-ice and enable us to identify and resolve model shortcomings and identify limits of predictability.

SIDFEx is largely the result of discussions held at various meetings, in particular in the context of the Year of Polar Prediction (YOPP), MOSAiC (, the Sea Ice Prediction Network (SIPN;, the Forum of Arctic Modelling and Observations Systhesis (FAMOS;, and the International Arctic Buoy Programme (IABP;

Recent information

The Python-based scripts for diagnostic tracking of ice particles have received a minor update on 24 October 2018; see below.

As of 17th January 2018, the list of SIDFEx targets has been updated. One buoy has apparently died and was thus removed from the list of active targets, and another buoy has passed Fram Strait and is already close to Iceland. We’ve decided to keep the latter for the time being, so including this one there are six active targets now. See here for the current list of targets.

A short report on SIDFEx has been included in the Sea Ice Prediction Network Sea Ice Outlook (SIPN-SIO) post-season report, available here. The SIDFEx section can be found at the very end of the report.

A presentation on SIDFEx from the MOSAiC workshop (May 2018) can be downloaded here, and another one from the Polar Prediction Workshop (May 2018) can be downloaded here.

A poster on SIDFEx, presented at a recent MOSAiC workshop (May 2018), can be downloaded here.

Background and guidelines for SIDFEx contributions

A document providing details on the design of SIDFEx and how to contribute drift forecasts can be obtained in the guidelines document here.

Contributors who would like to check in advance whether their files meet the formatting conventions (detailed in the guidelines document) may use this R function. How to use it is explained in the file header.


As detailed in the guidelines document, SIDFEx targets a number of buoys of the International Arctic Buoy Programme (IABP). The selected buoys are listed here, along with a near-real-time map showing their positions and drift history.

Forecast Results

After submission, each forecast is automatically processed and made publicly available in real-time (<1h delay) at the Cloud Service of the German Climate Computing Centre from this link. The results are ordered by contributor GroupIDs.

Automatic plots of recent results are under development, as are simple tools to browse, search, download, plot, and analyse the results.

Example scripts for tracing and submission

Our colleagues at NERSC (a big Thank You to Maxime Beauchamp and Laurent Bertino) were so kind to provide their Python-based scripts which they use to conduct the 2D-tracing based on ARC-MFC (TOPAZ) sea-ice drift forecast fields. These scripts are invoked every day by a cron job to generate the near-real-time metno001 contributions. The scripts also include the automated submission using curl . Obviously, the scripts need some adaptions if they are to be used by other groups and to other drift fields, but they might serve as an excellent template.

Note that the scripts received a minor update on 24 October 2018 to allow a temporal tolerance around the time of the last position observation. This helps avoiding gaps with respect to forecast initial times.

Download scripts (version 31 August 2018, uploaded 24 October 2018)

Download older scripts (version 14 May 2018)


You may contact us via email.

SIDFEx lead team: Helge Goessling, Axel Schweiger, Rüdiger Gerdes, Ed Blanchard-Wrigglesworth, Thomas Krumpen, Marcel Nicolaus, Robert Grumbine, and Ignatius Rigor.