The authors performed 12 LES simulations to depict the effect of the circulations induced by surface anomaly heating (patches) on the boundary-layer turbulence. Then analyzed the effects of the underlying surfaces and background flows on boundary-layer turbulence, the effects of patch-induced circulation on the turbulent intensity and heat flux, and the turbulence in the surface layer etc. Although this study is interesting, some editing and further explanations would benefit this manuscript. I am recommending minor corrections. Detailed comments are listed as follows:
General comments:
-Add Liu et al. (2018, 2020) into Introduction.
Liu, R., Liu, S.M., Yang, X.F., Lu, H., Pan, X.D., Xu, Z.W., Ma, Y.F., Xu, T.R., 2018. Wind dynamics over a highly heterogeneous oasis area: an experimental and numerical study. J. Geophys. Res. 123, 8418–8440.
Liu, R., Sogachev, A., Yang, X., Liu, S., Xu, T., Zhang, J. 2020. Investigating microclimate effects in an oasis-desert interaction zone. Agricultural and Forest Meteorology, 290, 107992.
-Line 82: Should describe specifically what kind of model is.
-Lines 151-152: "horizontal grid-spacing of 200 m. A vertically stretched grid with a minimum spacing of 1.1 m was utilized in the surface layer and a maximum of 64.8 m above 2000 m", 200:1.1, very large ratio. Is it ok for simulation?
-Line 171: What’s the real size of Ngoring Lake and Gyaring Lake? Does 30 km width reflect the real lake?
-Line 249: Please specify the time period of the daytime.
-Line 290: Please explain what the “h” means is.
-Lines 306-308: Please cite refs that can support this hypothesis.
-Figure 5: The heights of A1L and A1L_C is the same, why? The vertical coordinate may be zi?
-Lines 368 – 372: Why the effects of the heterogeneity on the TKE for the runs with balanced surface heat fluxes are less significant? Have other studies have the same phenomenon?
-Lines 399 – 415: Discuss the result with Zhou et al.(2018) and Liu et al. (2020).
Zhou, Y., Li. D., Liu, H. and Li, X.: Diurnal variations of the flux imbalance over homogeneous and heterogeneous landscapes. Boundary-Layer Meteorology, 168:417–442. https://doi.org/10.1007/s10546-018-0358-2, 2018.
Liu, R., Sogachev, A., Yang, X., Liu, S., Xu, T., Zhang, J. 2020. Investigating microclimate effects in an oasis-desert interaction zone. Agricultural and Forest Meteorology, 290, 107992.
-Section 4: What’s the difference between ambient wind, background wind and background flow?
Specific comments:
-Line 48: The sentence “…, which has improved our understanding of the transfer and spatial and temporal variability of the turbulence” is a bit redundant and it is unclear exactly what point you are making. I would suggest rephrasing.
-Lines 128 - 133: I would suggest rephrasing the sentence.
-Line 135: There are two “and”, please rephrase the sentence. The same as Line 217, Line 225 etc. Please check throughout the manuscript.
-Line 141: When was the Landsat image acquired?
-Line 150: Please specific the “135 km×30 km×6 km” means: Length? Width? Height?
-Figure 3: The legend should be “T(K)” in figs 3a and 3b. What’s are the units of w and u in figs 3c and 3d?
-Line 456: “fig.03” should be “Fig.S3”. The same as line 459. Please check “fig” or “Fig” throughout the manuscript and make them unified.
Technical corrections:
-Line 32: Miss interpunction between "m" and "s-1".
-Line 35: Change “it” to “them”.
-Line 90: Delete “,” after “heat”.
-Line 119: Should be the entrainment layers of PBL.
-Line 122: “data” should be “Data”.
-Line 248: “distribution” should be “distributions”.
We would like to thank the reviewer for taking the time to make detailed and useful comments. Details of the changes made are now given in the supplement in reply to the comments made.
We would like to thank the reviewer for taking the time to make detailed and useful comments. Details of the changes made are now given in the supplement in reply to the comments made.
Comments on “Large eddy simulation of boundary-layer turbulence over the heterogeneous surface in the Source Region of the Yellow River” by Zhang et al.
General comments
This research investigates the effects of circulations induced by strip like heterogeneity on the boundary-layer turbulence by using a Large Eddy Model which is initialized by the radiosonde profiles based on a filed campaign Ngoring in the summer of 2012. The effects of surface anomaly heating and background wind on the TKE were studies carefully. The contributions to the turbulent intensity and heat flux from the patch-induced circulations and background turbulence were compared through the phase-averaged method. The effects of heterogeneity on boundary-layer turbulence in the surface and entrainment layer are investigated as well. As is noted in the paper, other simulation about the effects of heterogeneity on the boundary-layer turbulence have been reported already in other papers, but I think it is interesting to have this LES study on the Tibetan Plateau where the few observations on the turbulence intensity and turbulence flux have been performed. In any case the paper provides the insights and comment that I have not seen elsewhere, in particular a description of detailed turbulence characteristics in the source region of the Yellow River.
My overall recommendation is that this ms is acceptable for publication on the Atmospheric Chemistry and Physics after minor revision.
Specific comments
(1). The authors use the quasi-three-dimensional large eddy simulations (LES) in this study. The horizontal model domian of 135 km x 30 km with the mesh grid of 200 m. My question is why did not the author use the higher LES resolutions in this study? I wonder if the resolution of 200 m is appropriate for a LES study? In addition, what is the timestep in the simulations?
(2). The thermal internal boundary layer (TIBL) would form when cold air passes over the warm surface. It has been reported that a large scale convective TIBL could form due to the surface heterogeneity. If there exists a TIBL when the air flows from the cold lake-patch to the warm grass land in your study? How does the TIBL affect the tubulence interaction over the heterogenous surfaces in your simulations?
Detailed comments
1) p8, line 164-165, here ‘various ambient wind’ refers to the initial wind or the geostrophic wind?
2) p11, Fig 2d, Is the unit (km) of the height in Fig. 2d correct?
3) p13, line239-240, sentence does not read well. You use three times ‘induced’ï¼reword it.
4) p13, line 251, 254, please unified ‘fig’ and ‘Fig’, and check all through the paper
5) p15, line 290, ‘with at a 3 h interval’ should be ‘‘with a 3 h interval’’
6) p17, line 325-327, Sentence does not read well, reword it.
7) p28, line 502, ‘confirms’ should be ‘confirm’
8) p30, fig. 13, I suggest plotting the joint distribution for cases of HOM, A1L and A2L in a panel instead of two.
9) I suggest the authors polishing the English proficience of this ms again.
We would like to thank the reviewer for taking the time to make detailed and useful comments. Details of the changes made are now given in the supplement in reply to the comments made.
We would like to thank the reviewer for taking the time to make detailed and useful comments. Details of the changes made are now given in the supplement in reply to the comments made.
We would like to thank the reviewer for taking the time to make detailed and useful comments. Details of the changes made are now given in the supplement in reply to the comments made.