

3D map of Earth shows the weather in real-time - dletozeun
http://earth.nullschool.net/

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teh_klev
Discussion from last week when this appeared:
[https://news.ycombinator.com/item?id=8733239](https://news.ycombinator.com/item?id=8733239)

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mtmail
Thanks. The previous discussion was titled "Bay Area storm" so I assumed it
was a local service/event only.

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nilkn
Here's another visualization based on this one:

[https://www.windyty.com](https://www.windyty.com)

This is also a cool demonstration of the Poincare-Hopf theorem (the "hairy
ball theorem", more colloquially), which states that the sum of the indices of
a vector field equals the Euler characteristic of the surface the field is
defined on. In this case, with a sphere, that Euler characteristic is 2 (it's
the same as for a cube, where you can use Euler's formula V - E + F), which
means the sum of indices is nonvacuous, i.e., there is at least one zero point
of the vector field.

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Xophmeister
The wind appears to be significantly stronger over open water. Is this just an
artefact of the visualisation, or is it a genuine meteorological phenomenon?

I understand the temperature differences between sea and land will make it
windier around coastal areas, but I had always thought that was a localised
effect.

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Swizec
You can play around with the altitude the visualisation is showing winds for.
I'm assuming a lot of wind is slowed down by topographical features at lower
altitudes. At 9000m and above there seems to be little difference between land
and sea in the visualisation.

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Gys
And discussed also about a year ago...

[https://news.ycombinator.com/item?id=6970350](https://news.ycombinator.com/item?id=6970350)

