Cloud ueights and Yelocities

Hokitika Guardian, 26 January 1923, Page 4

Cloud ueights and Yelocities

\X IXTER ESTIXG I’A PER WELLINGTON. Jan. 19"Cloud Heights from Melbourne Cbservaiofy Photograph's," was the title ot a paper read at. the Eeiopeo ( el’.g,< o lev Captain Kidson. M.Se.. v ietoria. Tile paper presented the lestil's ot •' series of photographs tak.-n ‘or tit" determination of the heights el ViVn-li-s tvr.es of cloud. These gave the Iv of cirrus clou.l, the marc's tail typo, as ranging between gtiOOPi and 12.1 it i f if l. Between 32,1100 ft and :it.( ><)'lit i» an inn portant layer in which t.m speed i I movement L greater than at any other level in the air, averaging in Inc! over 7(1 miles per hour. < irro-si rains cloud is slightly lower than cirrus. Cnrrostre.tus is the thin. high, pure while dnnd, often seen before the advent e' rainy weather. Solar and lunar bales arc produced in it. It shows a great concentration at 29,0000. Altoeumulns ciottd, which occurs in sheets ol dense and dark eluotllets, is more ot less closely connected together. Its height ranges from about 1f I .nt It) 11 to SJ.OOOft, but has a pronounced maxiniuni frequency at ld.OOOlt. At this height it usually lias a high velocity. It is suggested that in the region covered by this cloud, air is being sucked up info the higher levels. 1 iiis upliL of tbe air brings it into regions ol lower pressure. It. tbcroloic, expands and cools. Its moisture is thus condensed and falls in the form of rain. Other cloud types were also dealt with in the paper. The greatest veloeitv recorded by any ot the observations was 172 miles per hour. Observations made at Melbourne during the last 2. years by Air E. T. Quayle. ol the Central Weather Bureau, indicate that this velocity is very seldom exceeded. It is certainly unlikely that 800 miles per hour is ever reached, even at the zre a tost height. r I bis is interesting in view of statements recording velocities up to 350 miles per hour in North America. It hits been suggested that Lose enormous velocities, which occur n westerly winds, should he made use if hv specially constructed aeroplanes, rherc is nothing to indicate that any such scheme is possible in Australia, l'he paper forms a valuable addition to meteorological .knowledge in the Soufh>rn Hemisphere.