On Tue, 04 May 2004 05:41:18 -0400, Cub Driver wrote:

My understanding is basically the same except that it would be
the discovery of the jet stream over Japan, not the jet stream
per se.

Was it generally known? It seemed to surprise everyone when it
appeared over Japan, though I suppose it was journalists/historians
who were surprised, rather than meteorologists?

Before World War II, meteorologists suspected that something like the
jet stream must exist based on the observed movement of storm systems
and of high-altitude clouds. Most sources seem to agree, though, that
the existence of jet streams was not confirmed until they were
actually encountered in high-altitude flight during the war.

Is the jet stream over Japan the same altitude as elsewhere, or does
it move up and down so much as to make this moot?

Jet streams vary in altitude between about 6 and 9 miles, over Japan
and elsewhere. According to the web page at

http://www.historyhouse.com/in_history/balloon_1/

Japanese meteorologists independently confirmed the existence of the
jet stream using instrumented balloons during the winter of 1943-44,
and the Japanese incendiary balloon campaign from November 1944 to
March 1945 was based on the theory that the jet stream would carry
balloons across the Pacific from Japan to the west coast of the US.

(True, as it turned out, though only a small percentage of the ten
thousand or so balloons launched actually landed in the US, and the
only fatalities caused by the campaign were six picnickers who were
killed near Bly, Oregon, when they found a balloon and it detonated
when they tried to pull it down from a tree.)

How wide is the jet stream? On the evening wx forecast, it is always
depicted as a blue tunnel or worm (usually heading for New England).
Is it hundreds or thousands of miles wide?

Jet streams vary between about one and four hundred miles wide, and
one to three miles deep. Wind speeds of three hundred mph or greater
are possible in winter.


ljd