III—The Meteorological Limitations on Pressure Pattern Flying

The preceding papers indicate that the theory of pressure pattern flying assumes that the wind satisfies the conditions imposed by the geostrophic wind equation and that the atmospheric pressure distribution is not changing. These conditions are not satisfied in the atmosphere, and the errors caused by their non-fulfilment are discussed in the following paragraphs.Effect of departures of wind from geostrophic. The geostrophic wind equation is derived on the assumption that the wind blows uniformly without acceleration and without friction. These conditions are never satisfied in the atmosphere, nevertheless the practising meteorologist has found that the geostrophic wind represents a useful approximation to the true wind. There are certain exceptions of which the most important are in low latitudes and at levels below 2000 feet.

Observations of the amount of ozone in the earth's atmosphere, and its relation to other geophysical conditions.—Part IV

In the previously published papers on this subject it has been shown that there is a marked relation between the amount of ozone in the upper atmosphere and the type of atmospheric pressure distribution. By means of simultaneous observations at six stations in N. W. Europe, a fair idea of the distribution of ozone with different pressure distributions was obtained. To get further insight into this relation it was necessary to know the distribution of ozone layer the world at different times of the year. The instruments were, therefore, redistributed to get observations in widely different latitudes, and a year’s observations have been taken at these stations. While the results for one year cannot establish the annual variations with great accuracy, they are enough to show the main features, and several years’ observations would be necessary to give a greatly improved accuracy. The places where the observations have been made are as follows :─ Place. Latitude. Longitude. Arosa (Switzerland) ......................... 46° 45’ N. 9° 40’ E. Table Mountain (California) ....... 34° 22’ N. 117° 41’ W. Helwan (Egypt) ........................... 29° 50’ N. 31° 10’ E. Kodaikanal (India) ...................... 10° 10’ N. 77° 30’ E. Christchurch (New Zealand) ...... 43° 30’ S. 172° 40’ E.

Measurements of the amount of ozone in the Earth’s atmosphere arid its relation to other geophysical conditions.— part II

In a previous paper we have described in detail the method of measuring the total quantity of ozone in the earth’s atmosphere above any locality. Results of measurements made on about 200 days at Oxford in 1925 were also discussed, and it was shown that there was a marked connection between the amount of ozone and the general type of atmospheric pressure distribution, the amount being larger in cyclonic, and smaller in anticyclonic, conditions. As there is evidence that the ozone is entirely in the upper atmosphere, it was obviously desirable to investigate this connection further, and to see if it would throw any light on these meteorological phenomena.