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37 votes

Why do trees break at the same wind speed?

Why do trees break at the same wind speed? Image source: Wikimedia Commons Note that in the above image, that almost all of the trees had their tops snapped off. This claim is about tree's being ...
David Hammen's user avatar
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23 votes
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Why are there waves in seas towards shore - even in night?

Ocean waves (and also in mediterranean type seas and larger lakes, but on a smaller scale) are generated by two processes: locally generated waves ("wind waves"), which follow the direction of the ...
Ingvar Lukas's user avatar
14 votes
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What is the explanation of using pressure units (hPa) to express height when dealing with wind speeds?

There are several reasons. From the theoretical point of view it is beneficial to use isobaric coordinates, due to the vanishing density in the equations of motion. While in cartesian coordinates the ...
Joscha Fregin's user avatar
12 votes
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Do hurricanes cool the earth?

Hurricanes can be viewed as having primary and secondary circulations. The primary circulation is what we see in satellite photos, comprising the winds and clouds that circle the low pressure zone at ...
David Hammen's user avatar
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11 votes
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Why does wind blow offshore in the morning?

The phenomenon you describe is denoted as a land breeze. It is caused by a difference between the sea surface temperature and the land surface temperature. Surface Temperature During day time the ...
daniel.heydebreck's user avatar
10 votes
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How to calculate w-wind?

Omega, ω is closely related to w in meteorology. It can be moved towards w using the chain (this reminder from Watkins at SJSU helped)... ...
JeopardyTempest's user avatar
10 votes

How do these cloud forms grow?

Looks like Cirrus Fibratus (Ci fib) to me. See e.g. Wolkenatlas or Clouds Online. Regarding the formation of Ci fib, Name of Clouds says: Cirrus fibratus clouds are formed when winds at high ...
FuzzyLeapfrog's user avatar
9 votes
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Long-term Wind Speed Forecasting: reality or wishful thinking?

Warning: "long-term wind-speed forecasting for generation" has (at least) two very different meanings. One refers to forecasting a distribution of wind speeds; the other refers to hour-by-hour (or ...
410 gone's user avatar
  • 4,080
9 votes

Why do trees break at the same wind speed?

As the other answer points out, this is very likely an evolutionary adaptation that balances sturdiness with unnecessary overengineering. From a physics perspective, the relatively constant breaking ...
Nuclear Hoagie's user avatar
9 votes

What is a wind chill formula that will work from -10 C to +50 C and uses wind speed in km/h?

Wind chill is only relevant for cold temperatures. During hot temperatures, the affect of wind is to increase the felt temperatures. What would be more appropriate would be apparent temperature, also ...
Fred's user avatar
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8 votes
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What wind forecast datasets are available for forcing a wave forecast model?

Yes, the GFS model is a global model. The data is released in the public domain, so you can use it for free for any lawful purpose. See complete terms of use here. You can get the data here.
BarocliniCplusplus's user avatar
8 votes

Why do trees break at the same wind speed?

The general claim seems to be incorrect: This phenomenon is independent of type and size of the tree. Based on other answers, the claims around this appear to be that the scale of the tree doesn't ...
JimmyJames's user avatar
7 votes
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What is (negative) wind stress curl?

Skimming the paper, I believe the relevance of the wind stress curl is its relation to "Ekman pumping". I haven't found a simple, concise reference for this, but this page might be a good start, and ...
Jareth Holt's user avatar
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7 votes
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Can we extrapolate wind speed data to higher altitudes?

Yes, but it may not be valid. The extrapolation will be valid for about 0.1 * PBL Height using the Log-Wind Profile You will need: PBL Height. A second Wind speed (within 0.1*PBL Height) Surface ...
BarocliniCplusplus's user avatar
7 votes

Do hurricanes cool the earth?

To summarize David's great answer for folks perhaps looking for an answer more approachable to a wider audience: the answer is a thorough yes to the main question. Hurricanes do have a cooling impact. ...
JeopardyTempest's user avatar
7 votes
Accepted

Why do wind speeds often jump from 20 knots to 40 knots

This is an (annoying) artefact of BBC weather forecasts, and not an actual feature of the weather. At low wind speeds, the speed shown is the expected average speed. At higher wind speeds, the speed ...
Semidiurnal Simon's user avatar
7 votes
Accepted

ERA5 Data - How is a wind gust defined?

The WMO definition of wind gust for observing stations is, Maximum value, over the observing cycle, of the 3-second running average wind speed. which is the definition you've found. The ECMWF doc ...
Deditos's user avatar
  • 3,950
6 votes

Is wind just mainly nitrogen particles moving in one direction?

In a nutshell, you're a little bit right. The Air pressure is essentially Nitrogen and Oxygen molecules hitting our bodies, but that's true with and without wind. wind is more easily explained from ...
userLTK's user avatar
  • 5,857
6 votes

Plotting the wind direction in 3D?

The context I often see the u,v,w components shown in one plot are forward and backward trajectory plots like those from the NOAA HYSPLIT Model, which provides separate panels for horizontal and ...
f.thorpe's user avatar
  • 13.6k
6 votes

How are wind speeds typically distributed?

Yes, the most commonly used distribution for wind speed is the Weibull - at least when it comes to predicting wind speeds at prospective wind farm locations. Yes, the parameters vary. See, for ...
410 gone's user avatar
  • 4,080
6 votes

What is the difference between w-wind, vertical p-velocity and Omega?

I haven't come across the vertical p-velocity, so I am unsure what that is trying to communicate. w is the vertical velocity with units of length per second. Travelling away from the surface means ...
BarocliniCplusplus's user avatar
6 votes

What makes sand dunes shaped asymmetrically?

Saltation cannot proceed up a steeper slope under the wind conditions that prevail in the particular dune's formation. Dunes are basically traffic pile ups for wind driven sand grains, the slip face ...
Ash's user avatar
  • 4,270
5 votes

Plotting the wind direction in 3D?

Try quiver3 function in Matlab. For example, this is the example in Matlab's website for this function:
Ozcan's user avatar
  • 161
5 votes

If a prevailing wind traveled due east in the Northern Hemisphere, would the Coriolis Effect act on the water?

The Coriolis Effect occurs in all directions equally, even straight zonal (east-west) winds. Many indeed struggle with this idea - this Physics SE question has a fair explanation as to why. As ...
JeopardyTempest's user avatar
5 votes
Accepted

Does the Coriolis Effect affect a wind from East to West?

There have been a number of answers here that answer slightly different questions. As I understand it the question is "Why does the Coriolis force apply to objects (or air parcels) moving east and ...
Semidiurnal Simon's user avatar
5 votes
Accepted

SWAN wave model: HSIG is strangely low

You need to use the following line in your model setup: COORDINATES SPHERICAL Otherwise SWAN will try to calculate wave properties on a curvilinear grid with ...
Ingvar Lukas's user avatar
5 votes

Why do trees break at the same wind speed?

Some excellent answers are already available, but they are all examining a single tree in isolation, as if putting a tree to a wind tunnel to see whether it snaps or not. That's not how every trees ...
Jirka Hanika's user avatar

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