The open-access journals Polar Research (www.polarresearch.net) and Earth System Science Data invite submissions for two coordinated special issues. Submit your paper describing data sets, or the planning, instrumentation and execution of experiments or collection of data, to ESSD, and submit the companion manuscript – a research paper based on the same data – to Polar Research. Both papers must be submitted by January 2013. The special publications will appear in 2014. Submissions will be subject to the journals\' normal peer-review practices. Please note that acceptance by one journal does not guarantee that the companion paper will be accepted by the other journal. Please send questions or expressions of interest to the editors: Helle Goldman (Polar Research) and David Carlson (ESSD).