Undulations in the upper (higher elevation)air of the Westerlies are called jet stream disturbances, or _________, and are responsible for bringing variable warm & cold temperatures to mid-latitude (45 degrees and thereabouts) landmasses.
Rossby waves are upper-air waves troposhpere they usually have a wavelengths of range from 4000-6000. Rossby waves are large body of air with fairly uniform charactersitics of temperature and moisture.
