Abstract
The influence of anomalous solar activity as indicated by the index of solar flares or that of geomagnetic disturbances on the mean variation of atmospheric ozone was investigated statistically by the superposed epoch method on the basis of data covering the period of IGY, IGC and 1960.
No appreciable characteristics that exceeded the level of 5% confidence limit were detected in the low latitudinal zone as regards the influence of solar flares.
But regarding the effect of anomalous geomagnetic disturbances, the ozone was found to decrease as much as about 1% and 0.5% of the total amount, respectively, on one or two days before the key day in the low latitudinal zone, and on just the key day in the auroral zone.
The photochemical processes coming from X-ray enhancement due to solar flare in the former case and of auroral origin in the latter case, were proposed to explain the mechanism of this ozone decrease. Also thermal effect was inferred to follow this which may possibly play an important role in the following dynamical process.
Regarding the ozone variation after the geomagnetic key day in the auroral zone, ozone was found to decrease in a remarkable degree on the fifth day and then on the eighth day the longitudinal distribution of the northern hemisphere showed a characteristic wavelike pattern presenting a maximum region in the North Atlantic Area which might be compared with the trough developement in the 300 mb level on the same day in a similar area previously discussed by MACDONALaDn d ROBERTS(1960) or with the tropopause depression pointed out by RASOOL(1961).
