wind provenance - where does it come from
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A simple question but, currently affected by a cold spell from the east (UK news, 2021-02-03, the Beast from the East II) potentially non-trivial, is it possible to show where our current air mass came from?
You could just use Windy to follow the current wind flows backwards but that would not be correct because to back trace the path of a current air packet you need to integrate against increasing distant past and not current flows. I'm trying to work out in my head what a solution to this problem would look like but I suspect it may be a well studied problem. Also air move between different altitudes? Unfortunately, I don't know anything about fluid dynamics. The question is real however: as some one asked "does this snow come from the North or from Russian?"
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@willeda1
You can use HYSPLIT from NOAA
https://www.ready.noaa.gov/HYSPLIT.php
More precisely https://www.ready.noaa.gov/hypub-bin/trajtype.pl
to get these trajectories
On Windy there is the Trajectory plugin available, however it does not show ‘from where the air comes from’ but ‘where it goes’.
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@willeda1
With Windy, you can use the wind and temperature map and go to 500hPa or around 5500m (using geopotential height) to get an idea about air massa movements and temperatures of the massa.
Another idea is to use the temperature map and go to 850hPa to follow the temperatures of the different air massa, you can animate to follow the directions of the different massa. -
@idefix37 Many thanks. That is really cool. I'm really impressed by this - it's an insight into another world.
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@yves70 Many thanks for this. It puts a new light on everything.
