Comments on the paper entitled: Turbulence,billows and gravity waves in a high shear region of the upper atmosphere by K.H. Lloyd,C.H. Low and R.A. Vincent

Some of the observational evidence which leads to the conclusion by Layzer and Bedinger (1969) that the small scale structure of high altitude vapor trails is not produced by preexisting atmospheric turbulence is recalled briefly in response to the recent report by Lloyd, Low and Vincent (1973). Specifically noted are: the difference in the structure of the ‘up’ and ‘down’ trails, the delay in appearance of the globular structure, and the equal frequency of occurrence of globules in regions of low and high wind shear. It is concluded that the observation presented by Lloyd, Low and Vincent does not alter our conclusion which is based on a large number of trails.