Extreme wind shear events in US offshore wind energy areas and the role of induced stratification

Debnath, Mithu; Doubrawa, Paula; Optis, Mike; Hawbecker, Patrick; Bodini, Nicola

doi:https://doi.org/10.5194/wes-6-1043-2021

Articles | Volume 6, issue 4

https://doi.org/10.5194/wes-6-1043-2021

© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

https://doi.org/10.5194/wes-6-1043-2021

© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 6, issue 4

Research article

|

10 Aug 2021

Research article |

| 10 Aug 2021

Extreme wind shear events in US offshore wind energy areas and the role of induced stratification

Mithu Debnath, Paula Doubrawa, Mike Optis, Patrick Hawbecker, and Nicola Bodini

Download

Final revised paper (published on 10 Aug 2021)
Preprint (discussion started on 17 Sep 2020)

Interactive discussion

Status: closed

AC: Author comment | RC: Referee comment | SC: Short comment | EC: Editor comment

- Printer-friendly version

- Supplement

RC1: 'na', Anonymous Referee #1, 11 Oct 2020
- AC2: 'Reply on RC1', Mithu Debnath, 03 Mar 2021
RC2: 'Review of manuscript "Extreme Wind Shear Events in US Offshore Wind Energy Areas and the Role of Induced Stratification"', Anonymous Referee #2, 11 Oct 2020
- AC1: 'Reply on RC2', Mithu Debnath, 03 Mar 2021

Peer-review completion

AR: Author's response | RR: Referee report | ED: Editor decision

AR by Mithu Debnath on behalf of the Authors (03 Mar 2021) Author's response Manuscript

ED: Referee Nomination & Report Request started (03 Apr 2021) by Andrea Hahmann

RR by Anonymous Referee #1 (12 Apr 2021)

RR by Peter C. Kalverla (17 Apr 2021)

Suggestions for revision or reasons for rejection

I’m very happy with the revised manuscript. It was already relevant, but the improved embedding in the literature and the updated discussion throughout the manuscript make it much more credible. I’d like to compliment the authors on their thoroughness in addressing the feedback on an earlier version. That said, on reading the manuscript again I stumbled upon a few minor issues, and I’d like to give the authors a chance to address these before the manuscript enters the editorial process. They are listed below.

Fig 6, 10, 11, 12. I find these overlaid bar plots rather difficult to read. Red is much more pronounced than blue. The (irrelevant) vertical lines on the bars clutter the figure and distract from the important parts. Perhaps consider changing the plot type to line/scatter?

P9 L170: “but it may” instead of “but may”?

Fig 9f: why did you choose to show the shear exponent on the x-axis, rather than the wind speed gradient itself?

P14 L222: “… reasons for having events being observed” please consider rewriting this sentence.

P14 Section 3.4: The content is fine, but the readability of this paragraph is a bit less pleasant than the rest of the manuscript.

Fig 11a: maybe add a note that this figure may not be entirely representative for the climatology, since inter-annual variability can be substantial?

Fig 11b: I find it a bit confusing that a polar plot is used here. So far that’s only been used for directions. If the reason is that time is circular, then 11a should also be a polar plot. But I think a normal Cartesian plot is easier to interpret. If you decide keep the polar plot, consider rotating it such that it aligns with an analogue clock.

Fig 12a: The legend doesn’t correspond with the line types shown in the figure

Fig 12: VLLJ -> LLJ in legend of a, y-axis of b, and x-axis of c. Also fig 13 legend.

Fig 12b: why is there no KDE fit here?

P16 L266: “monotonic shear profiles not included”. Why not? So do I interpret this correctly that the “no-shear” and “LLJ” do not add up to 100%, because the monotonic high shear profiles are excluded? Or is it “LLJ” vs “everything else”? The latter seems to be implied in L264.

P17 L278: “comprise of” is this grammatically correct?

P18 L301: “Expanding to consider … it may not be a good characterization of all events”. What does “it” refer to? The entire synoptic setup with a low and high pressure system, or the additional strengthening and eastward propagation? If it is the latter, please clarify the sentence. If it is the former, it seems to contradict previous statements about 75% of the events.

P18 L306: “not shown is the wind shift”. But this has now been added to the figure, right? Maybe consider labeling the panels from a – h instead of 2 x (a – d). That would make it easier to refer to them.

P18 L315: I’m not sure what “shortwave troughs” are. Can you add a reference or briefly explain?

P19 L324: I wasn’t too familiar with the “Mid-Atlantic” region. So this leads to Northerly shore-parallel winds at the offshore lease area? How does that work in terms of stability and warm air advection? It feels like a whole different mechanism. It would be helpful to also see a schematic of this setup. Could it be added in figure 14 (as this figure now only uses half the width of a page)? In my opinion, the distinction between two different 'types' of events (or at least their synoptic configuration) is a very important and new feature of this paper, and adding this setup to figure 14 would highlight that point.

P21 L368: This study is based on 1 year of measurements. It would be valuable to repeat it with more data. Will this dataset be extended?

Hide

ED: Publish subject to minor revisions (review by editor) (02 May 2021) by Andrea Hahmann

AR by Mithu Debnath on behalf of the Authors (13 May 2021) Author's response Manuscript

ED: Publish subject to technical corrections (04 Jun 2021) by Andrea Hahmann

ED: Publish subject to technical corrections (04 Jun 2021) by Jakob Mann (Chief editor)

AR by Mithu Debnath on behalf of the Authors (11 Jun 2021) Author's response Manuscript

Short summary

As the offshore wind industry emerges on the US East Coast, a comprehensive understanding of the wind resource – particularly extreme events – is vital to the industry's success. We leverage a year of data of two floating lidars to quantify and characterize the frequent occurrence of high-wind-shear and low-level-jet events, both of which will have a considerable impact on turbine operation. We find that almost 100 independent long events occur throughout the year.