The vertical distribution of atmospheric ozone in high latitudes

Abstract

In conjunction with Dr. Götz we have recently given an account of a new method of finding the vertical distribution of ozone in the atmosphere, and have used this method to determine the distribution above Arosa, Switzerland. It was found that the average height of the ozone in the atmosphere was much lower than had previously been thought, and these results have since been confirmed by Professor Regener who has obtained ultra-violet spectra from small balloons up to a height of 30 km. So far the vertical distribution of ozone has not been found anywhere except in Switzerland and in view of the connection between the variations in amount of ozone and atmospheric pressure distribution, and with polar and equatorial air currents, it was of interest to know the distribution in high and low latitudes also. By the kindness of Professor Vegard and the Norwegian Committee for Geophysics arrangements were made to take one of the special photoelectric spectro-photometers for measuring ozone to Tromsø (latitude 69° 40' N., 18° 57' E.) where observations were carried out at the Nordlysobservatorium during May and June, 1934. It had been hoped that by taking observations in the early summer some days with very high that by taking observations in the early summer some days with very high ozone content would have been found; unfortunately this did not occur and the ozone content only ranged from 0·230 cm to 0·294 cm, 13 good days' observations being obtained in all. The method of deducing the distribution of ozone which was used was similar to that employed in the Swiss observations (Method B) to which reference should be made for all details. Suffice it to say that for purposes of calculation both air and ozone are assumed to be concentrated into a number of thin layers. Owing to our better knowledge of the distribution gained through the Arosa work it was decided to recalculate the results for the assumed fundamental distribution, the effect of the lower height of Tromsø also being allowed for. Since the sun never set during part of the time, it was impossible to get observations when the sun was on, or below, the horizon; hence the "sunset theory" used at Arosa, which gives the amount of ozone in the highest layer, could not be employed and we have assumed that the ozone content of the atmosphere above 40 km is the same as that found at Arosa. Further, it was decided that there would be a gain in general accuracy if it were assumed that the amount of ozone in the lowest layer was equal to that in the next higher layer, since this reduced the number of variables.