Artificial satellites represent the latest application of modern technology to the study of the weather. The first of these was the American Tiros I, launched from Florida in 1960. Orbiting the earth about 14 times a day, it transmitted several hundred televised pictures daily, showing in surprising detail the distribution of clouds as seen from a height of about 400 miles. Storm centres could be easily identified from their cloud pattern, and it was possible to detect incipient tropical cyclones over the open ocean some days before their existence could be inferred from the scanty reports received from areas such as the tropical Atlantic and Pacific. Tiros I and its successors have provided a vast amount of research material which can be expected to yield results of considerable importance for weather forecasting. They are very costly devices, however, and it remains to be seen whether the results will justify their continuance on a routine basis, unless possibly by an international sharing of the costs.

by Neil George Robertson, M.SC., Assistant Director (Climatology), Meteorological Service, Department of Civil Aviation, Wellington.