The paper is essential for understanding the aurora generation mechanisms. It is well written and can be published as is.

General comments:

This paper presents really interesting comparisons between a time-dependent kinetic code, named AURORA and rocket measurements in the upper ionosphere (VISIONS-2). The paper deserves publication since many interesting and new points are described. However, it needs modifications especially because some features need clarifications, the description of the code and the comparison between the simulations and the data particularly. Some calculation choices need better justifications.

I recommend publication after major modifications

Main points:

In the simulations, the number is grid elements in energies and altitudes is never mentioned. It is the same for the limits of these grids. For example, line 129, an energy of 5 keV is mentioned. Is it the higher energy considered? The kind of grids must also be clarified. Are they linear or exponential or built in another way?

For the altitude, it also exists an ambiguity: Fig. 2 shows simulations up to 600 km, but it is mentioned line 206 that the top of the modeled ionosphere is above 400 km. Please clarify.

In the simulations also and considering that the time step is much shorter than the measurement time resolution, the initial conditions are not clear. Is it the one shown in the top panel of figure 2 or the precipitation during the previous measurement time bin?

It could also be interesting to described how the precipitation input is managed regarding the data. Is it smoothed in time or do the authors change them abruptly?

The choice of the time stamp in the simulations presented in figure 2 (0.041,….) are not justified. Is it arbitrary or does it have a specific justification? Please clarify.

It is similar for the time step. On line 129, a step of less than “500 µs” is mentioned. Did the authors use the same time step in the shown simulation or a smaller one?

In figure 3, the simulated precipitations are stopped at 0.45 s in the Alfevenic case in order to visualize the decrease of the ionization rates. The authors must justify why they do this in the Alfvenic case and not in the other case (quasi mono energetic).

Last major point: It is not clear why, in Figure 6, the simulations after 0.45 s are different from the observations for all pitch angles. This discrepancy is not mentioned in the text. Please clarify.

Minor other points:

The term "mono-energetic" is confusing since the precipitations are not fully mono-energetic. Perhaps quasi mono-energetic should be closer to the reality.

In lines 166 and 170, it is mentioned twice, “which is believed to be the sign of DAWs followed by references. It could be useful, behind the references, to explain in a few sentences what the phenomenology behind these possibilities.

Line 140: It should be mentioned here that “prompt” emissions make the difference between allowed and forbidden transitions in the dipolar electric approximation and that it excludes the green and red lines, which are long-lived transitions and thus forbidden.

Line 189: Why the 10-20° and 20-30° pitch angles are merged. This must be justified.

Lines 222 to 229 and relation with figure 3: It should be mentioned in the text that the red line is the altitude of the emission peak.

In the legend of figure 4, please give the full spectroscopic notation of the state and not only B3. Mention also that it is the v’-v 5-1 transition of this band and not the full band. The same goes for the 427 band, which is the 0-1.

The paragraph between lines 242 and 248 is confusing; it is mentioned above that the forbidden transitions are not taken into account. The authors could remove it or better justify why they mention these two emissions lines here.

Figure 6: A small arrow appears in the left top panel (case a, angle 0-10°). Does it have a signification?

Line 288-290: I think it is necessary to be more prudent when saying that simulations reproduce the observation. I suggest “reproduce in many cases the observations but not all of them.”

Line 330 : Please be more precise when writing “high resolution.” Does it concern space or time. resolution or both?