METEOROLOGY.

Star (Christchurch), Issue 16942, 17 January 1923, Page 4

METEOROLOGY.

INTERESTING OBSERVATIONS. ( p er Press Association.) WELLINGTON, January 16. The subject of wind frequencies, which has an important bearing upon meteorological observations and j weather forecasts was discussed by the | meteorological section at the Science Congress, when gome interesting paper* were presented. Captain Kidson. of j Melbourne, in his presidential address ( dealt with advances made by the Scandinavians, especially the Norwegians m meteorology as a. result oi being com polled to maintain their forecasting service without reports from belligerent countries during the great war. What had hitherto been regarded a typical cyclone Was now recognised as ono stage only in the life history of a cyclone. It was possible to recognise from the characteristics of an individual cyclone its age and its further i developments. Thus it might be po~ ■ sible to say that a “ low ’’ pressure which had been reported as moving eastward from Australia. acconiDan;.- i by gales of wind, would diminish :u intensity as it approached New Zealand. with corresponding moderation of winds and seas. On the other hand, if the depression were recognised as young one it would be possible t< warn shipping to expect increasing winds and rough seas. The theory also gave a complete account of various ways in which rainfall is produced. This was worked out in great detail. The results of observations of winds of the upper atmosphere at Wellington and at Apia (Samoa) were presente I by Professor Emersden. who describe*l experiments conducted at Victoria College during the last six months with balloons. By means of tlieodolytes 1: was able to ascertain wind velocities n. various heights. The most interesting result was that, although most of the prevalent wind at tho surface was northerly, yet above (5000 feet it was southerly. Tie found that a very abrupt change occurred in the direction of the wind between 5000 and 7000 feet altitude. This, lie remarked, was quite peculiar to Wellington, and it looked as though Wellington wind; were really confined to surface leve : -> alone. Higher upwind conditions were no worse than in other centres. It appeared as if cyclones in the lower were sucked into the harbour through the straits, and the city being near the centre of activity experienced greater winds than would be the oas* otherwise. This data will be used ir. the testing of Captain Kidson’s theory. If the theory is proved correct it will be possible to make weather forecasts two or three weeks ahead. Similaobservations at Apia, Samoa, showed that tho south-east trade wind at tho surface changed into a steady west, south-west wind at. forty miles per hour above the height of 10.000 feet. The result is that it would be advantageous in travelling by aeroplane ’•» Fiji or Samoa to follow lower levels, arid to take the higher levels above 15.000 feet on the return journey, which would afford a steady forty or j forty-five miles per hour wind. The i authorities at the Samoan Observatory, ; he stated, had considered these results, | and had decided to continue investigations every day during the present year, with the object of working out | complete data.