Replies to first round of reviewers comments

Dear co-authors (@thober, @lese, @rkumar),

please feel free to review our responses to the first round of feedback from the reviewers (major revisions requested). I added markdown files RC1-AC1.md, RC2-AC2.md, RC3-AC3.md with my draft of responses to their feedback. The original reviews are also added here, but can be also found in the Copernicus page. The referred manuscript version can be loaded in the "MPR_GMD" project shared with you on Overleaf.

I feel we need to address their criticism of too many technical and few scientific parts as well as the overall paper organization. Please provide some feedback, if their proposed paper structure changes can be met by a) mere Renaming/Reframing of the section title to fit the Intro/Methods/Results/Discussion structure or b) if you feel that blending section 2 in other sections and deflating section 3 and inflating section 4 is necessary.

What would benefit the paper most and meet their call for more "scientific" content, is another application where we might show how TFs and UOs can be developed. From the top of my head, I could imagine a relatively simple (few distributed parameters) groundwater model at three resolutions where we let FSO estimate parameters from soil or geological information. We could optimize the TFs/UOs matching the measurements from pumping tests. However, this is still lots of work to be done.

Best and thanks very much Robert