The "Polar Vortex" effect was noted back in the early 70’s, but was referred to as "Circumpolar Vortex". Originally the (Circum)Polar Vortex was the middle latitude wind that blew around the Poles from west to east. The faster moving segments with speeds above 30 m/sec (108 kph), were designated as Jet Streams. Over time, the entire circulation became known as the Jet Stream. The wind current pattern had early on, been identified by pressurized US B-29 (Superfortress) high altitude bombers during WWII.