I stumbled across this interesting site, easy to use and see whats floating about up above and how fast, e.g. the jet stream is now back in it's more usual position mucking up our skies and theres a bit of SO2 in our lungs...
earth :: a global map of wind, weather, and ocean conditions (https://earth.nullschool.net/#current/chem/surface/level/overlay=so2smass/orthographic=0.00,51.50,1714/loc=0.000,51.50)
Interesting, and it looks like where you are in France gets as much of the jetstream and we do.
Carole