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 ...
- 23.2k
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 ...
- 1,145
13
votes
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Plotting wind barbs in python
Your uwnd variable holds 32 bit floats and has shape (1,73,144) corresponding to time, lat, lon and is located in the Dataset ...
- 14.1k
12
votes
Is this ice cover real - and what circumstances are required to make it?
Yes, it is real. Whoever took the photo, congratulations on a very fine image.
I have never seen this texture on such a scale, but something similar can be achieved in the laboratory by creating a ...
- 14.2k
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 ...
- 23.2k
11
votes
Accepted
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 ...
- 2,661
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)...
...
- 8,713
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
Accepted
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 ...
- 4,090
9
votes
Is this ice cover real - and what circumstances are required to make it?
This picture was taken in what seem to be a small pond, of very calm water. It seem that in ideal conditions, implying but not limited to :
absence of winds
clean water eg: no nuclei to provide an ...
- 2,633
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 ...
- 24.6k
8
votes
Accepted
Would there still be wind if Earth had no water?
I wouldn't say water is naturally cooler than air. What I would say is that water has a higher heat capacity than air. This means it takes more energy to affect the same increase in temperature and ...
- 14.1k
8
votes
Accepted
About an alternative type of wind energy facility
This has been tried to some extent; Strata in London was a skyscraper that was built with three wind turbines at the top, with a deliberate design to funnel wind into them. There are other examples.
...
- 5,800
8
votes
Accepted
How do weather services measure wind
Weather stations and airports around the world almost always include an anemometer. Because of ground friction, the wind speed varies with height, so instrumental deployment is set at a standard ...
- 14.2k
8
votes
Help interpreting a wind rose diagram
No, you've misunderstood it. There's lots of information you're missing. Every data point is information, and you've listed a tiny proportion of them.
Furthermore, 4-7 km/h and 11-16 km/h aren't ...
- 4,090
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.
- 8,684
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
Where can I get archived hourly wind speed data for Germany?
The MERRA dataset has data for the world from 1979 to date. It updates frequently.
You can get the data as HDF or NETCDF. If your GIS package doesn't read those, there will be translation packages ...
- 4,090
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
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 ...
- 8,684
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.
...
- 8,713
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 ...
- 5,800
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 ...
- 3,940
6
votes
Accepted
How do I represent wind direction on a UTM (Universal Transverse Mercator) map projection?
Meteorological winds are referenced from North being 0$^{\circ}$ increasing in a clockwise direction. Additionally, they are named for the direction the wind is coming from. Your vector on the map, ...
- 14.1k
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 ...
- 4,090
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 ...
- 13.5k
Only top scored, non community-wiki answers of a minimum length are eligible