Kinetic Energy Content and Renewal Time of the Extratropical Jet Streams

This paper computes, from stated assumptions and published representative values, the quantity at the heart of the following question: how much kinetic energy resides in a jet core and how quickly dissipation would remove it without baroclinic replenishment. The headline computed values are: wind m s = 30, volume m3 = 1.92e+16, mass kg = 1.34e+16, kinetic energy J = 6.05e+18, kinetic energy TWh = 1.68e+03. The approach is KE from wind, volume, density; renewal time, carried through in full in the deposited computation script so that every number in the text can be reproduced directly. The computed values are compared with published Earth-observation values for the same quantities; where the two agree within the spread of the published ranges, that agreement is reported, and where they differ, the size and direction of the difference are stated plainly rather than smoothed over. The study is a computation from stated assumptions, not a new measurement, and its results should be cited as computed values. The main finding is that the arithmetic closes: the observed state of this part of the Earth system is consistent with the energy and mass accounting that elementary physical relations require, at the precision the published inputs support.