How can the jet stream return to normal zonal flow after rossby waves build?

Jet streams are quick streaming, thin, wandering air ebbs and flows found in the climate of a few planets, including Earth. It can come back to ordinary zonal ±ow after Rossby waves work through partition of a mass of chilly air from the fly stream.

Iam pretty sure it is c. 2000 bce

Answer erosion,oil spills,pollution,tourism,urban development;