U.S. WEATHER RESEARCH

Press, Volume LXXXIX, Issue 27072, 22 June 1953, Page 8

U.S. WEATHER RESEARCH

STUDY OF JET AIR* STREAMS

HIGH-VELOCITY WIND CURRENTS (From a Reuter Correspondent.) WASHINGTON Record-breaking flights of today may be the scheduled airline runs of tomorrow, when science announces that it has timetables for the so-called “jet air streams,” and accurate weather, forecasts months in advance could become commonplace.

Meteorologists are coming to the conclusion that the jet streams are responsible for major weather patterns. Old as the earth itself, they were unsuspected until World War’ll. Then Japan-bound bombers, flying above 10,000 feet, reported west-east winds reaching 250 miles an hour—more than three times hurricane velocity. Since then, science has learned that the Northern and Southern Hemispheres each have jet streams, almost invariably blowing from west to east. Neither is found below 10,000 feet nor above 40,000 feet. Speeds of the winds may reach 300 miles an hour. The paths of these jets are narrow. Military pilots who now regularly search them out report that flights of a few hundred miles will usually take them right across a speeding stream. No one knows for sure what forms them. But some believe that it is the encounter of masses of cold and warm air. In the winter, the Northern Hemisphere stream speeds generally above the Gulf of Mexico, and in the summer it moves north, to the latitude of Oregon. Unfortunately for those who would learn their secrets, jet streams curve, meander, zigzag, speed up and slow down, sometimes even stop altogether, a recent bulletin of the National Geographic Society explained. "Obviously, when the pattern behind all these gyrations is found, modern aircraft, particularly jets, which perform best at high altitudes, vjill always be able to find a roaring tailwind or avoid a headwind,” said the bulletin. “Just as obviously, the nation which first knows about jet stream schedules is going to have a big military advantage. Bombers and guided missiles high in the jets can move faster and farther Because of the military angle, much research on jet streams has been cloaked in secrecy.” But meteorologists have disclosed some of their weather findings. When a jet stream curves southward, for example, it may suck in cold polar air, bringing cool weather in its wake. Conversely, a turn to the north can create a void into which hot air from the tropics immediately rushes.

Much of the jet tracking is done with weather balloons, but recently Navy pilots have begun flying regularly from a Maryland base in search of the streams, with orders to "buck across them” and report on their ways.