Diagnostic study of cloud distribution and development in hurricane ``Debbie'', Aug. 13-19, 1969 from satellite data

• Published in: Tellus 1977-01, Vol.29 (5), p.402-414
• Main Author: Balogun, EE
• Format: Article
• Language: English
• ISSN: 0040-2826

A diagnostic study of cloud distribution and development in hurricane ``Debbie'', Aug. 13-19, 1969 by using satellite data and based upon a photometric method, described earlier by Balogun (1976), is presented. A systematic assessment of the cloudiness of a tropical cyclone over the oceans by a method that is less sensitive to personal bias demonstrates the following features of the cyclone: 1) the gradual changes in the cloud patterns of a tropical cyclone; the changes take place in a definite manner; 2) the nonaxis symmetric nature of the tropical cyclone cloud pattern; the lack of symmetry at the early stages of the cyclone is quantified. The parameter obtained is used to demonstrate the process of symmetricalization at the latter stages of the cyclone; 3) The rate of rotation of the cloud bands about a central axis of the cyclone is less than the rate of rotation of air parcels around the axis of rotation. The rate of rotation of the bands is estimated to be 50-75% of the rotation of air parcels. This estimate was for a period of seven hours during the lifetime of the cyclone. The lower rate of motion of the bands suggests that the field of the low-level convergence moves at a different rate from the air parcels around the axis of the cyclone.