|Comments to authors|
In general, the manuscript has been largely improved with including the new data and expanding the data analysis part; total volume is nearly the twice as the previous one at this stage. On the other hand, I have got a feeling that it became too wordy. I hope the authors eliminate the repetitions and the redundant part, and make the manuscript more compact.
Further, I am still concerned about the surface topography. In fact, 5 mm rise over 130 mm is not enormous and is inevitable in nature, I understand. However, as you may see, particle motions are very sensitive on the surface feature. Thus, I am afraid that the particle speed in Fig. 6 and the horizontal flux in Fig.7 are strongly affected, even though the terrain-following coordinates are adapted. Such as, the particle located at x=60 mm and z=10 mm has a history which passed over the snow surface at x=0 mm where the snow surface is 5 mm lower. It should be carefully taken into account in the analysis. Although it is not shown in revised version, in Fig. 3 (g) of the previous manuscript, particle flux showed the maximum at 2 to 7 mm high. This is presumably caused by the effect of topography change.
Bagnold (1941) used the term ‘creep’ to describe grains rolling and jostling along the surface. Thus I do have slightly an aversion to call the particle motion less than 4mm as creep. Probably “reputation” that means “move slowly” introduced by Ungar and Haff (1987) is more suitable. At any rate, 4 mm is several tens times larger than the mean particle diameter and, needless to say, large number of saltation particles are involved there.
Further, although it is not related to the evaluation of the contents directly, the authors need to reply to the reviewer’s comment line by line. ‘Refer to the response to other reviewer’ is not an appropriate attitude.
As a whole, I do believe this manuscript is approaching to the publishing stage. However, I am glad if the authors can clarify and improve some of the points listed below before the publication.
Specific comments are listed below.
Page 4, line 23: I do not see where the potential for adapting the continuum model to the blowing snow phenomena is discussed in the manuscript.
Figure 5: (a) to (c) are not shown in the figure. The scale of the vertical of upper two figures needs to be set equal.
Page 9, line 4: We cannot expect the steady-wind condition in nature, except for the specific situation like in Antarctica.
Page 10, line 6: Why don’t you say “the focal point was not recognized in this study”?
Figure 6: Please check the figure caption. d) - f) are for the particle velocity gradient and g) – i) are for the particle slip velocity.
Page 15, line 18: I don’t see how you can expect the dense surface flow with profiles in Figs. 6 and 7. The particle number flux increases with approaching the bed surface, but no specific layers with maximum flux are recognized. In actual, as pointed previously, in Fig. 3 (g) of the previous manuscript, particle flux showed the maximum at 2 to 7 mm high. However, this is presumably induced by the topography change.
Figure 8: In the figure caption, no explanation that this is for just “descending particles” is shown.
Page 17, line 11: Shear stress due to the wind can be estimated from the ultra sonic anemometer data. Thus, it will be informative to compare with the particle momentum near the surface quantitatively.
Page 17, line 23: The definition of three height bands should be defined earlier, when the data of near-surface and high bands were introduced.
Page 24, line 27: Descriptions of the article number concentrations will be useful to discuss whether it will be comparable with the ordinary fluidized-bed and be applicable the physical properties of the bed.