Make Okular notes visible in acrobat

There doesn't seem to be any way to do so within Okular, but you can save Okular annotations back into pdf format with Xournal by "printing to a file":

The more recent releases of Okular save the annotations directly into the PDF.

For example, on Ubuntu, if you go to the Ubuntu Software Center and install Okular, then it should work fine out of the box.

(for more details, see here)

The annotations done in Okular are stored in the ~/.kde/share/apps/okular/docdata folder.

There should be a .xml file for each annotated pdf.

In the future, you may want to use PDF X-Change viewer of Foxit Reader for Windows through Wine. These sava annotations in the pdf itself and are visible in Adobe Reader or any other pdf reader for that matter.