Dear L Kramer

Thank you for addressing the comments and questions and for preparing the revised version of the manuscript. The changes to the manuscript improved it significantly and I agree with the referee that the manuscript should be accepted for publication after minor revision. Thus, I kindly ask you to consider the comments of the referee.

The manuscript focuses on transport phenomena, but at the same time it gives a much more conclusive picture of Arctic atmospheric chemistry by discussing the various aspects such as photochemistry, boundary layer physics, metrology, and transport. I still had difficulties to clearly identify the new aspects, for example in 3.1.1 Reactive nitrogen oxides. Maybe a short summary at the end of this (and other) section would help and/or adding more references to earlier work. For example on page 15; that NOx and NOy peak at different times has been mentioned in Grannas (2007) and others have modelled this (such as Jones 2010, or references in Grannas 2007).
These key reviews in the ACP special edition also fit nicely to your introduction, in particular Grannas 2007 and Anderson 2008). I might add that the release of HNO4 from the snow with increasing temperatures is supported by our laboratory studies (Ulrich 2012).


I hope that these comments are useful for the final minor revision.

Kind regards,
Thorsten Bartels-Rausch.


REF:
http://www.atmos-chem-phys.net/special_issue80.html

T Ulrich, Markus Ammann, S Leutwyler, and T Bartels-Rausch., Atmos Chem Phys, 2012 vol. 12 (4) pp. 1833-1845. http://www.atmos-chem-phys.net/12/1833/2012/