The correlation between the 5577 A night airglow intensity and geomagnetic activity

Abstract

The relationship between geomagnetic activity and the intensity of the 5577 A [O I] line in the night airglow is presented. The correlation that is used accounts for missing data in the airglow time-series and, what is more important, allows for the effects of the high correlation between successive data points. The results for the period studied (1953)(1954)(1955)(1956)(1957)(1958)(1959)(1960) indicate an inverse relationship between airglow intensity and the geomagnetic index K, for values of the index between 0 and 7 and a direct relationship for index values of 8 and 9. Statistical tests show the inverse relationship to be marginally significant at the 5 per cent confidence level. The direct relationship for values of K• equal to 8 or 9 depends on a total of 10 data points; although much emphasis on this result is premature, it is not inconsistent with previous results. Introduction. This paper is concerned with the correlation of the 5577 A [O I] airglow intensity atSacramento Peak, New Mexico (geographic latitude 32ø47'N, longitude 07 h 03 m W, geomagnetic latitude 41.6 ø, altitude 9260 feet) with magnetic activity for the 8-year period 1953-1960.Since 1922 a number of papers reporting on the relationship of 5577 A [O I] intensity and magnetic activity have appeared in the literature. The conclusions reached by the various authors appear very often to have been inconsistent and, at times, contradictory. Consequently, we feel that it is worth while to present a fuller account of previous work than is customary, in the hope that the reasons for the inconsistencies will be clarified. In 1922 LordRayleigh published a paper presenting the results of a study of the intensities of the auroral green line in the night sky for the period from February through June 1921. Rayleigh [1921-1922] made photographic exposures for an entire night using a prism spectrograph. He then visually estimated the intensities from the plate a•d classified them into three groups of increasing intensity: 0, 1, and 2. lie compared the green-line intensities with the degree of magnetic disturbance at Kew, which was also measured on an increasing scale of 0, 1, 2. A comparison for the individual nights indicated no correlation between the airglow intensity and magnetic disturbance with the exception of one occasion (May 13-14) when a great magnetic storm was accompanied by an aurora of high green-line intensity. A comparison of the average intensities for the entire period with the magnetic character figures also indicated that no correlation existed. 2255 NIGHT AIRGLOW INTENSITYAND GEOMAGNETIC ACTIVITY NIGItT AIRGLOW INTENSITY AND GEOMAGNETIC ACTIVITY

Power-spectrum analysis of local geomagnetic disturbances and their relationship to cosmic-ray and aurora intensity

“…Nevertheless, an approx three months recurrency was found for the 5577 A (2p4 'D -2p4 'S) in the [01] airglow intensity as measured in the Maruyama Observatory for the period 1957-1961 but was attributed to limited data sample in order to justify the single/double spring maximum observed in Sacramento Peak Observatory for the period 1955-1960, that breaks this recurrency. Whilst Sacramento Peak data showed a correlation between Kp and [01], the Maruyama data did not show such a relationship (see also Silverman et al, 1962). Silverman (1970) explains this as due to the fact that [01] varies with KP as a function of the magnetic latitude.…”

Observation of the O I 5577 A nightglow at Christchurch, New Zealand

“…where the integrated solar flux has a different seasonal variation. We find that at lower latitudes the nightglow maximums become more equinoctial, that is to say, instead of a peak in midsummer, stations at latitudes less than 35 ø observe a maximum shortly after the spring equinox [Barbier, 1963;Ward and Silverman, 1962;Silverman et al, 1962]. The other maximum, in the fall, seems to occur more or less simultaneously at all latitudes less than 50 ø in the same hemisphere, except that it does appear to take place earlier near the equator.…”

Upper atmosphere nightglow disturbances during the geomagnetic storm of December 15, 2006 over Eastern Siberia

“…At the same time, results of different studies of the 557.7 nm emission response to GS are of a contradictory char acter [4][5][6][7][8].…”