The authors have made a number of modifications based on the comments of the reviewers. This has tightened the paper. There do however remain some areas highlighted by the reviewers that the authors have not yet adequately dealt with in my view (A-D). I judge these to be technical in nature and not too taxing - thus I am satisfied that this does not need to be further-reviewed beyond me as AE. I ask for a further set of changes in response to A-D below and a point-by-point list of changed made to incorporate these changes into the next submission version.

A) CLEAR WATER CONDITIONS INDICATE THE SCALE OF FTURB. (Point 7, Reviewer 2 also)
> Can you add a few sentences and beef up the "justification" to satisfy this point more fully please - several of the reviewers raise this point and it is not really dealt with in the revisions. It is a basic assumption that is likely not valid - so you need to address this please.

B) TURBULENCE EXTINCTION OCCURRS AT LOW AND HIGH ABSOLUTE CONCENTRATIONS
> Can you add a sentence on this in the introduction also - there are a few papers you could cite there in a background review that would make this section easier to manage and introduce.

C) Referee 2 Pt 2 - QUADRATIC
his is an important point that is not adequately dealt with yet. Please revisit this.

D) Referee 2 PT 5 - GRAIN SIZE
I do not agree that this is beyond the scope. Please revise the paper to include points pertaining to this advance - sight of the discussion around this is sufficient rather than additional results - but this is novel and will make the paper stronger.

Daniel R. Parsons

There are a set of considered and thoughtful revisions - and responses - that address the additional points raised by the reviewers and highlighted in AE. I am happy that this now progresses to full publication.
Daniel R. Parsons

Dear Authors,
Thank you for your submission to ESurf. I am delighted to inform you that your paper has now been accepted for final publication.
Best wishes,
Tom Coulthard