AID TO AVIATION

Poverty Bay Herald, Volume LXII, Issue 18858, 8 November 1935, Page 5

AID TO AVIATION

UPPER AIR CURRENTS DOMINION CONDITIONS VALUABLE DATA SECURED (Special to the Herald.) WELLINGTON, this day. The linking up of New Zealand with the world's principal air routes has brought into prominence the work of the Meteorological Office in connection with the study of upper air currents. It has been going on since 1929, and will shortly be extended, so that when there are commercial services across the Tasman and the Pacific to Auckland, much valuable data will be available to the pilots in making the most economical course.

Unlike the ship's captain, who has to cope with surface currents which he cannot avoid, the aviator is frequently able to get out of adverse air currents by changing his altitude, until he gets a fair wind. One of tlie best examples is the discovery of Imperial Airways' pilots, who in crossing the Timor Sea to Darwin, are sure of a fair wind at a certain altitude. When they are on the reverse journey, a change of altitude . brings, them .into . a . steady . .wind blowing away from Australia. Investigations in New Zealand have not so far produced so favorable a set of conditions. Balloon observations in Auckland and Wellington suggest that over most of New Zealand the wind tends to become more westerly at high altitudes, increasing in velocity with the height. The airman approaching from Australia would therefore fly high, and get a strong favorable wind. On the journey from New Zealand to Australia it is likely that most trips will he against a head wind, for no reversal of the upper current has been discovered to match the conditions over the Timor Sea. However, if the trans-Tasman commercial service of the future makes well north at the earliest moment, it will generally be able to get the advantage of the easterly winds of the equatorial regions. EFFECT OF LAND MASSES Land masses have an important influence on the direction of the wind at low levels. Around Wellington, for instance, the winds are nearly always north-west or S.g.E. because of the funnel effect of Cook Strait and its borders of high mountains. As the higher altitudes are reached in this area, the wind currents are less disturbed and become more westerly, in line with the general conditions around the DominionWhen heavy southerlies are blowing, the balloon observations show that this wind reaches a high altitude. From Christchurch and Wellington, every morning at 9 o'clock, officers of the Meteorological Office send up rubber balloons iilled with hydrogen. In fine weather, they use a light color, the balloon being inflated until it has a diameter of 90in. In the bright light it is very prominent and can be easily followed by the observer using a theodolite, recording speed and direction of the currents every 500 ft. Balloons are frequently kept in sight for 30,000 ft- and sometimes to 50,000 ft. Their usual fate is to be lost at sea. When there is heavy cloud, blue is the selected color for the balloon, while the presence of broken clouds leads to the use of a red balloon, which shows up well either against the cloud or blue sky. .Commercial aviation projects are now so close to the practical stage that. this work is likely to be extended, and, the Meteorological Office already has a large quantity of data to be "worked' up" for use in aviation.