WORLD'S THUNDERSTORMS

Evening Star, Issue 19001, 24 July 1925, Page 3

WORLD'S THUNDERSTORMS

SIXTEEN MILLION A YEAR In investigations relating to atmospheric electricity tho frequency of thunder in the various parts of the world is an important element, and a knowledge of the subject is especially valuable in connection with the establishment of air routes. Some interesting data bearing on the distribution of thunderstorms over the globe, compiled by Mr C. E. P. Brooks M.Sc., arc contained in a memoir just issued by the Air Ministry Meteorological Office, states the ‘ Daily Telegraph.’ In this publication the monthly and annual frequency of storms is discussed on tho basis of records taken over a number of years at 3,265 stations, of which 2,680 are in Europe, together with a largo number of observations on board ship. Maps arc given showing the average frequency during the year, and also during October to March and April to September. The monthly frequency in each of the continents and oceans and over the world as a whole is also shown in tabular form.

It is considered that a. station will probably record those thunderstorms which occur in a surrounding area of 200 square miles. If the earth’s surface is divided up into 1,000,000 sections, each with an area of nearly 200 square miles, there will bo on the aver- : ago sixteen thunderstorms in each area during a year - , making a total of 16,- | 000.000 thunderstorms nor annum, or 4-1,000 a day. Taking the average, duration of a thunderstorm as one hour, there will, therefore, be in progress at any ono moment about 1,800 thunder- I storms in different parts of the world, j What does this mean in terms of i lightning Hashes? During a thunder- | storm at West Norwood ninety-eight i lightning Hashes were counted in j twenty-eight minutes, which is at the ! rate of approximately 201) per hour. | This figure, it is stated, may be taken I as approximately correct lor a severe temperate or an average tropical storm. Thus 1,800 storms will give 860.000 lightning Hashes over the whole globo iiT mi hour, or an average of 100 per , second.