Cirriform clouds over India- Heights and Temperatures

Aviators and meteorologists alike have now-a.days become increasingly concerned with cirriform clouds. Information regarding the characteristics of cirriform clouds over tropical countries is very meagre. All available data of these clouds obtained by high-altitude aircraft flights ovor India during the last seven years have been analysed. These include reports of the meteorological reconnaissance flights by the I.A.F. aircraft an.d Met. reports by civil jet aircraft. The mean heights of cirriform clouds, their extremes thickness and amounts have been computed. The diurnal, regional and seasonal variations are also discussed. Other parameters investigated include turbulence, winds, icing and visibility in and near these clouds. A typical synoptlc situation giving rise to extensive cirriform clouds is also presented.