JET STREAMS OF AIR WILL AID AIRLINERS OF FUTURE

Press, Volume XCII, Issue 27752, 1 September 1955, Page 9

JET STREAMS OF AIR WILL AID AIRLINERS OF FUTURE

“The Press” Special Service

WELLINGTON, August 31. Jet streams of air, the high speed winds of the upper atmosphere, reaching speeds of up to 250 miles an hour, have been known for little more than 10 years, yet they promise to offer pilots of the future a great many advantages and problems. The existence of the winds become known to the public of New Zealand, and the world, when pilots flying Canberras in the London-Christchurch air race told of following jet streams of more than 100 miles an hour. Flying with such a stream, a jet aircraft with a speed of 500 miles an hour would be accelerated to nearly 700 miles an hour. Against the stream, the jet airliner would be reduced to 1940 speeds. The streams, up to 300 miles wide, and a few thousand feet through, are now well known to weathermen and jet pilots, said the officer in charge of research for the New Zealand Meteorological Service (Dr. J. F. Gabites) in a recent address.

Discovery During War The existence of these jet streams was first discovered by 829 bombers raiding z Tokyo.” said Dr. Gabites. “They had the uncomfortable experience of standing still over their targets—caught in winds which occasionally reached more than 250 miles an hour.

“The reports, of these fantastically high wind speeds were at first met with near-disbelief. Meteorologists and pilots were amazed by their readings and experiences. “The growing use of radar in tracking high-level balloons for wind measurement. however, revealed many features of the world’s air flow which were not even suspected only 10 years ago,” said Dr. Gabites. Used occasionally by aircraft — London-Christchurch air race Canberras and North Pacific (Japan-San Francisco) airliners—the jet streams were now known to occur most per-

sistently between latitudes 25-35 in both hemispheres. In these subtropical latitudes they blew during the winters.

“Perhaps the best-developed jet stream flows across south-east China and southern Japan,” said Dr. Gabites. “Here, the average wind speed at 40,000 ft is about 140 miles an hour. Other well-developed jet streams were found across the south-east States of the United States, and across North Africa.

“In the southern hemisphere, the jet lies across the centre of Australia and eastward between New Zealand and Fiji. The average wind speed in winter at 45,000 ft in the latitude of Raoul and Norfolk Islands probably exceeds 100 miles an hour and occasionally exceeds 200 miles an hour.”

After two years in the United States, he had been attached to the United States Far East Air Force at the outbreak of the Korean war, said Dr. Gabites. He had been concerned with hurricane and jet stream research and information. The jet streams were particularly important in jet fighter operations, as they could considerably reduce aircraft range. To meteorologists, they were important as a little-known manifestation of the transfer of solar energy between the tropics and the temperate zones of the world. “The major objective of the meteorology programme for the International Geophysical Year is to make the observations necessary to throw more light on the way the sun’s energy is transformed into the energy of the jet streams encircling the globe, and how the energy is dissipated in cyclones,” said Dr. Gabites. “Not only should the insight we hope to gain help in predicting the behaviour of jet streams to the benefit of aviation, but it should bring us a long way toward the prediction of periods of stormy or settled weather a long way ahead.”