Jet Stream

Trying to get clear on the Jet Stream, that all-important high altitude
air current which largely determines we go between polar cold or southerly
warmth here in Southern Canada.

It would be a mistake to view it as a ribbon: it moves faster on the East
Coast of the US than the West. This tells me it is fed more...duh!

Interesting as well that - contrary to fluid dynamics - the notion
of vertical in meteorology refers to the altitude component or vector,
and that of horizontal, the latitude position or vector. In fluid dynamics,
we are given a resulting position between two points.

De ce fait, l'air ainsi transporté depuis l'équateur ne peut dépasser une certaine latitude, à partir de laquelle sa vitesse deviendrait trop grande dans le sens ouest-est ; au niveau de cette latitude, il s'écoule en partie vers le sol, fermant alors la boucle de la cellule de Hadley, et en partie vers l'est, où il reste au niveau de la tropopause : c'est ce second flux d'air qui, dans chaque hémisphère, génère un courant-jet "planétaire".

Thus, the air transported from the equator cannot get past a certain latitude, from which
its speed would become too great in the West-to-East direction; at that latitude, part of it
will fall toward the ground, thus forming the envelope to the Hadley cell; and the other part
towards the East, as it stays at the level of the upper troposphere: it is this second air flux
which, in each hemisphere, creates a 'planetary' Jet Stream.

trnaslation: doxa-louise

http://www.meteofrance.fr/publications/glossaire/150103-courant-jet

Thus a lower Jet Stream necessarily moves more slowly.
And a Ferrel cell between a Hadley cell and a Polar one acts as
a heat pump, moving hot air to a heat sink ie making cold air
colder, between a Hadley cell and a Polar one.

source: Wikipedia