|The efforts of the authors to address the review comments is noted and many of the confusions and ambiguities were clarified. Admittedly, this is not a manuscript focused on the turbulence modeled with the LES used to transport particles. However, the conclusions of this manuscript are explicitly dependent on this model, and have been shown by the manuscript to only exist BECAUSE of the LES. As such, care should be taken to not include tangential results without the necessary supporting evidence. At hand there are still a couple points of contention that should be addressed prior to publication.|
Response A.14: It is unclear whether this is the complete answer to the comment or not. Please clarify if this is a typo.
Response A.21: The authors responded to a question of the impact of surface sublimation on suppression of vertical motions. However, the question posed was actually on the potential presence of a temperature gradient in the atmosphere as could be found in a typical stable boundary layer in calm wind over snow. However, as is mentioned below, it is suggested that these comments on vertical suppression just be removed altogether. It is unclear whether it was intended to imply that there is no such temperature gradient in nature with turbulent mixing, or that such a temperature gradient only exists if there is actively sublimating surface snow?
Author Response Page 4, First paragraph: “with the air is so close” Please correct
Author Response Page 4, Last Paragraph “lighther”
Track Changes version of Manuscript:
Page 5 Line 3: Please add citation that these values are typical for saltation.
P6 L15-16: Do you mean “or”
Section 3.1 The use of LES is very attractive to many people in hydrology and snow science, but the complexity of such an endeavor is often the limiting factor. Please explicitly cite the software used, be it in-house code or a modified commercial product? It is appreciated that the governing equations of motion are included, but for a model of this nature, a note on where the code was actually developed (or ideally, available) would be beneficial to the community. As well, please note in the main body of text that is LES of a channel flow.
P8L22: “to decelerate”
P10L7: Fix units
P10L8: “Mean wind speeds.” It may be stationary, but it is still a turbulent flow.
P10L13-17: This doesn’t seem to be supported by the supplement. It is not clear that there was vertical suppression because of sublimation, only vertical suppression during saltation. This
claim seems like it would need further investigation, for example a comparison with saltation without sublimation to show the actual impact of the cooling. Obviously TKE drops, but that is insufficient to show SUPPRESSION of vertical motions by thermal effects. The buoyancy is a function of vertical motions, so that is a bit of a circular argument. I suggest removing comment of any causal relationship between sublimation and vertical motion suppression until the referenced future research is conducted.
The information now included in the document supplement is helpful in grounding the manuscript solidly in the cryospheric field of study, and will likely help connecting the manuscript from a purely numerical study to a broader snow science audience.
-Figure 1: The 40% reduction in windspeed with the presence of saltation is substantial and should be commented on. There are numerous wind tunnel (and some field) studies addressing momentum extraction from the wind by particles in saltation. This 40% should be put in context of previous work to add credibility to an inherently complex model of a “simple” scenario to be found in nature.
-It is claimed in the manuscript that turbulent mixing of different temperatures is responsible for the regeneration of warm dry air that then results in different rates of sublimation for LES. It would be illuminating to have a movie showing an animation of evidence of that process, as it is the heart of the conclusions presented here.