I actually never considered not making our data open.
A collection of datasets, well-documented with metadata, available on the data repository Zenodo through the Creative Commons license.
Prof. Julia Schmale actually never considered not making data open. But if you wanted a reason, performing measurements in such remote regions like the Southern Ocean is a considerable effort and depends on limited opportunities. Sharing data openly is the only way to advance our understanding of this vast but largely understudied region. There are many research groups out there who can use the data differently from how her team use them, thereby creating a much wider range of knowledge than she ever could, if she kept them for herself.
There is a large international research community, including the IPCC climate and earth system modelers, who are highly interested in Southern Ocean data.
All in all, it’s simple: Prof. Schmale’s group processes the data according to the best practice in their field, and describe them in the meta data such that non-experts can use them. Of course, given the amount and heterogeneity of the data, there is considerable effort involved in streamlining processes.