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 ...
- 23.9k
23
votes
Accepted
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 ...
- 561
14
votes
Accepted
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 ...
- 1,165
12
votes
Accepted
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 ...
- 23.9k
10
votes
Accepted
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)...
...
- 8,822
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 ...
- 221
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 ...
- 380
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 ...
- 24.8k
8
votes
Accepted
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.
- 8,809
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 ...
- 196
7
votes
Accepted
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 ...
- 8,809
7
votes
Accepted
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 ...
- 1,381
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.
...
- 8,822
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 ...
- 5,820
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 ...
- 3,960
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 ...
- 13.8k
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 ...
- 5,140
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:
- 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 ...
- 8,822
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 ...
- 5,820
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 ...
- 561
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 ...
- 191
5
votes
Does global warming inhibit transport of moisture?
Increased air temperature tends to increase the rate of moisture transfer, firstly because at a given relative humidity and pressure warmer air has a higher absolute humidity and is carrying more ...
- 5,140
5
votes
Are there any types of winds or waves that are produced just by Earth's rotation?
Yes. Such a thing is called an inertial oscillation.
Kelvin waves are not examples of inertial oscillations. Kelvin waves balance the earth's rotation against the normal force of a topographic ...
- 8,809
4
votes
Accepted
Why would Earth have stable weather patterns if it stopped spinning and vigorous weather if it had a much faster rotation?
Weather modeling is crazy complicated so I don't want to make this sound absolute, but Venus virtually doesn't rotate and it has much faster trade winds than Earth. Venus has low surface wind speed ...
- 5,897
4
votes
Accepted
How to identify low or high pressure area
Because you specifically asked about winds and pressure, there is a fairly applicable rule of thumb. It's called Buys Ballot's Law. Basically, if the wind is to your back (coming behind you), and ...
- 8,822
4
votes
What is the definition of wind gust?
Doesn't appear to be great sources out there for some of this info! (But then, that's what StackExchange has great promise in being!)
In the US, this manual for the official instrument setup, as ...
- 8,822
Only top scored, non community-wiki answers of a minimum length are eligible