Comment on se-2021-21

The manuscript on Seismic radiation from wind turbines: observations and analytical modeling of frequency-dependent amplitude decays is an important contribution to better understand and predict seismic emissions from wind turbines. Measurement results from a well-chosen experiment are presented together with a new approach to model emissions from several wind turbines such as typical wind farm installations.

The manuscript on Seismic radiation from wind turbines: observations and analytical modeling of frequency-dependent amplitude decays is an important contribution to better understand and predict seismic emissions from wind turbines. Measurement results from a well-chosen experiment are presented together with a new approach to model emissions from several wind turbines such as typical wind farm installations.
The two main results are clearly outlined: attenuation factors for a long-term measurement (6 month) and the influence of phase shifts from multiple sources on the emission amplitudes. However, I recommend a revision before publication: A description of the geology / underground is completely missing (e.g. after line 68). This information is important to understand seismic velocities and quality factors which depend on the physical rock properties.
The influence of wind parks A and B ( Fig. 1) must be explained in more details. Are there large wind turbines which may affect the measurements ? What happens if they radiate emissions in phase ?
What is exactly meant by using the 25% quantile (line 81). Does this mean you exclude 75% of the data ? How sensitive is this selection ? Would it make a difference to use the 20% or 40% quantile ? Do you exclude time windows with earthquakes waves ? This should be clarified in the manuscript.
The peaks at relatively high frequencies of 6.0 Hz and 7.6 Hz are the highest ones. How can this be explained ? Which operational modes of the wind turbines are these ? Please explain.
Section 2.2 on amplitude decay: this is on PSD amplitude decay as described in lines 104-106. To makes this clear, PSD amplitude decay should be written in lines 106, 109 and 121.
It would be helpful to include the amplitude decay for waves in the time domain. Therefore, a conversion should be applied (factor 0.5). Then the resulting b-values can be better compared with typical wave properties, e.g. 0.5 for geometrical spreading of surface waves. In addition: in Fig. 5,  Line 165: Quality factor Q: You do not mention seismic scattering. Especially for high frequencies this may contribute to the wave damping.
Equation (3): A constant amplitude A is used. I understand that this is a reasonable start for modelling. However, it should be mentioned that wind turbines emit timely and azimuthally varying signal amplitudes (e.g. Lerbs et al., 2020: Fig. 6-8). This will modify the results below as well as should be considered in real cases.
Section 3.2: It would be helpful to add some sentences on the wave pattern off the profile and add comments for a non-uniform signal amplitude A (eq. 3).
4 Results: The Q value for low frequencies (40) is quite low. Does this fit with the physical properties of the rocks in the subsurface at >100 m depth ? I guess this could be a solid and compact limestone.
Generally, I am missing a comparison of the vs and Q values with the actual rocks along the profile. Fig. 13: What requires a third layer (half space below the second layer) ? Why don't you use a one-layer model with a half-space below ? Lines 265: not "until" but "down to"

Results and
Line 266: Fig. 13 appears in the text before Fig. 10-12 -please re-sort.