Talk:Jet stream

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This article says jet streams flow from east to west. Other web pages dealing with jet streams say the opposite, that the winds flow from west to east.

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Tropical or subtropical?

The article says "Northern Hemisphere (stream is) between latitude 20°N and 50°N for the subtropical (sic)". Should that last word be subtropical or tropical without the prefix "sub"? Moriori 02:27, Apr 9, 2004 (UTC)

article states that jet streams were discovered during WW II by Wiley Post. He actually died in 1935, but did discover them.

Contents 1 Discoverd by Thaddeus Lowe? 2 Ooishi and Esperanto? 3 Fire balloons 4 Factual error about Wiley Post 5 Fastest speed 6 Tailwind caused a stall

[edit] Discoverd by Thaddeus Lowe?

The article about Thaddeus Lowe says:

Thaddeus Sobieski Constantine (alt. Coulincourt) Lowe (1832–1913) was an American engineer. He was exactly 29 when he proposed the idea of observation balloons during the American Civil War. During the Civil War, he became the commander of the United States' First Balloon Corps division. He flew the Intrepid, one of six hot air balloons used during the Civil War in addition to the Enterprise. While doing so, he was captured as a spy in North Carolina. He later used his knowledge of balloons to discover the jet stream.

Actually I doubt that... - Alureiter 18:14, 11 November 2005 (UTC)

[edit] Ooishi and Esperanto?

The article says that Ooishi's work on the Jet Stream "went largely unnoticed outside of Japan as he chose to write in the international language of Esperanto which was little read in scientific circles."

And Japanese *was* widely read in scientific circles in the 1920s??? The way the matter is phrased to me seems boardering on being non-neutral towards Esperanto...

I don't think so - it would be true if he wrote it in any other language than those commonly used in international science circles (French and German for that era, I think, although I am very much uncertain of that). It's not a comment on Esperanto, it's a comment on the language used not being a language commonly used in scientific papers of the era. 69.162.59.13 14:31, 27 February 2006 (UTC)

In my rewrite I've addressed this. Esperanto was preferred by scientists like Ooishi whose native languages were unlikely to be read by Europeans. Unfortunately, the Europeans didn't get the message. ;-) After WW2 English became the scientific language of choice. --Dhartung | Talk 22:24, 7 June 2006 (UTC)

[edit] Fire balloons

The article says:

"It was however utilised during World War II by the Japanese military in the fire balloon attacks on the American mainland (see below)."

But there is nothing below on the fire bombs :( 129.241.11.199 14:26, 17 March 2006 (UTC)

This is now hyperlinked to the article fire balloon Ma.rkus.nl 16:01, 21 August 2006 (UTC)

[edit] Factual error about Wiley Post

"During World War II the American aviator Wiley Post.."

Wiley Post died in 1935. WWII started in 1939 and the U.S. entered the war in 1941. Clearly either the timeframe is wrong or it was not done by Wiley Post. MichaelSH 04:27, 27 May 2006 (UTC)

It's incorrect to write this as a competition between Ooishi and Post. Not even Ooishi fully understood what he had discovered, and the paper that was already linked to as the source did not overstate this, but its description here did. I've used that source to write a fuller history of the process of discovery that gives due credit to others including the German who first coined the term. --Dhartung | Talk 22:22, 7 June 2006 (UTC)

Thanks for clearing this up. The article now makes sense. MichaelSH 23:48, 10 June 2006 (UTC)

[edit] Fastest speed

According to Guinness World Records 2006, a jet stream speed of 656 km/h (408 mph) was measured above South Uist December 13, 1967. More on the subject here.

[edit] Tailwind caused a stall

My comment refers to the Jet Stream article found at http://en.wikipedia.org/wiki/Jet_stream. The text in question is quoted here:

“A 1943 Royal Air Force raid on Gironde, France, encountered tailwinds that sped them to their target, but returning the same headwinds, estimated at 380 km/h, caused their aircraft to stall, and the crews were forced to parachute into occupied Vichy France, where they were captured.”

I’m having trouble with the suggestion that the same headwinds, on the return trip, caused the aircraft to stall. Airplanes fly within the air mass and as such have air speeds. It really doesn’t matter which direction the air mass is moving, the aircraft is transiting that air mass at an airspeed that will allow it to continue flying. If they somehow tried t slow the aircraft’s airspeed to provide a given ground speed, then it would be possible to slow the aircraft (airspeed) sufficiently to allow it to stall (a pretty dumb thing to do).

There is a phenomenon encountered by airplanes approaching airports for landing (low altitude, slow airspeed, & perhaps hanging numerous lift/drag devices such as flaps and landing gear) in which a headwind quickly changes to a tailwind effectively causing the airspeed to drop to critical levels (and possible the aircraft to crash). This “wind shear” effectively steals the lift from the wings and unless the pilot can return the airspeed to flying speed quickly, they will likely crash.

Even if the 1943 flight encountered such a wind shear at altitude, it should not have caused the aircraft to stall and the crew to abandon it. Altitude is your friend in these situations and the 1943 flight should have been able to trade altitude for airspeed sufficient to maintain controlled flight.

If I missed the point of the article, I apologize in advance. Please accept these thoughts in the spirit in which they were intended.

Thank you for an excellent article. —The preceding unsigned comment was added by 70.188.252.180 (talk)

Removed the text since no citation was added, and the statement does sound quite unlikely to me. Kumiankka 22:12, 30 March 2007 (UTC)

The statement comes from the article on Ooishi in the External links section:

Flohn (1992, p. 13) [Oral history memoir]

An English bomber squadron encountered NNE headwinds of 380 km h−1 (~106 m s−1) on return from a raid over Gironde (west coast of France) in 1943. Crews parachute from stalled aircraft and are captured by German Army.

The source cited is a German memoir Flohn, H., 1992: Meteorologie im Übergang Erfahrungen und Errinerungern (1931–1991). Ferd Dümmlers, 81 pp. It is only a report, but it was included in the overview used to rewrite this article, so I thought it significant. Flohn being a meteorologist and not an aerospace engineer I don't think we can determine whether it's realistic or not, but it is sourced. --Dhartung | Talk 01:42, 31 March 2007 (UTC)