It is an interesting and careful analysis of the complex flow in the Advent valley – a flow that has been the focus of several publications throughout the years.

The manuscript is focused on wind energy and the conclusion is interesting – that the optimum for wind energy production is wind turbines located in the valley with a hub height of approximately 100 m, thus taking advantage of the frequent LLJ in the valley.

I have a few points:

1. (1): As written in the text it could be understood as if A is the sweeping area of the wind turbine and thus covering heights with varying wind speed. The WPD is the available power for a unit area at a given height. Please clarify this in the text.
2. (3): The equation for the log wind profile is: u(z) = (ustar/kappa) * ln(z(zo) thus kappa in Eq.(3) is misplaced (inverse). It is not clear if this is just a typo or it will have implications on the use of the log law for the rest of the paper.
3. Line 114: It is not clear what is meant by “at least 9 min of measurements with a 10% availability”. This suggests, although it is stated that the analysis is based on 10 min averages, that the analysis is based on the original raw 1 Hertz data from the wind lidar? What is the threshold CNR? 10% availability is very low – I suggest repeating the analysis with an availability of say 50% and see if this changes the result and conclusions. A lower CNR threshold combined with higher data availability might be preferable.
4. I note that motions caused by waves in the stable atmosphere of the valley also might contribute to the flow pattern. Please discuss.

Review:

Title: The influence of local winds on wind power characteristics in a high Arctic valley

by M. Henkies, K. Høyland, A. Shestov, A. Sjøblom

general comments

This study investigates the influence of local winds on wind power characteristics in a Svalbard valley, using long-term observations from a wind profiler, lidar, and weather stations. The observations show the development of various wind systems, driven by thermal gradients, the terrain and synoptic conditions. Different wind regimes are discussed in detail. They conclude that a wind speed maximum was observed at around 80–100 m, and the wind power density maximum at 120–140 m. This is useful information for setting up wind power stations in an Arctic valley and the authors provide valuable recommendations for different locations. The observations analyzed in this study are of high value, as the boundary layer structure and its wind field in such complex, non-homogeneous terrain are still not well understood and adequately parameterized in models.  The study supports the scientific community in deepening the understanding of the polar boundary layer structure and wind fields in complex terrain. This is particularly important given the lack of knowledge due to the lack of boundary layer data from Arctic mountainous regions and the limitations of numerical models, which often perform inadequately in such environments and conditions, which is also shown in the paper

The introduction is clear and provides a good overview of previous boundary layer studies in this area. The theoretical background is well described, and the methodology is sound. The Adventdalen valley is a suitable experimental site, with long-term wind data at different sites that allow for seasonal analysis and the various observing locations give a good spatial coverage. Key data have already been published by the authors, and other datasets are openly available. To summarize: the research question is both important and original. The conclusions regarding the placement of wind power stations and the types of turbines suitable for a high Arctic valley are well supported by the data. The paper effectively demonstrates the importance of using local wind observations in complex terrain, rather than relying solely on models or wind atlas data, which often have a too coarse resolution.

The paper is well suited for publication in Wind Energy Science Discussions. The topic is timely and relevant, and the methodology is robust. The text is generally well written.

I do not have any major corrections/suggestions, just minor

technical corrections:

• Line 89, page 5: The word "still" sounds a bid odd at the beginning of the sentence. I suggest replacing it with something like: “It has to be kept in mind that...”.
• Line 84: the von Karman constant is written inverted incorrectly; it should be U(z)/U*=1/k log(z/zo).
• Lines 199, 204: Please include definitions of katabatic and anabatic winds for clarity.
• Figure 4, 5,6: Did you have in your calculation code for the logarithmic power law, which is shown in the graphs, the von Karman constant correct or inverted (see previous point line 84)?
• Figure 7 caption: I suggest including in the caption of Figure 7 after “individual weather stations,”  “see locations in Figure 1”.