Behauptete Einfl�sse des Mondes auf die erdmagnetische Unruhe und ihr statistischer Hintergrund

Bartels, J.

doi:10.1007/bf00632687

Cited by 9 publications

(4 citation statements)

References 5 publications

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“…Hence it will be assumed that variations of the contours at a given L value in Figure 13 The formation of ducts with L > 1.2. The lifetime of ducts depends on the flux of ionization into or out of the ionosphere [Cole, 1971;Bernhardt and Park, 1977]. At night the flux is small so that a slow decay rate would be expected.…”

Section: I/r---1/n Dn/ds (1)mentioning

confidence: 99%

“…1-12, it is observed that for the L range 1.4-1.6 the percentages for a given local time are remarkably similar for all dip latitudes below about 30 ø. This is likely because any density irregularity occurring in the upper ionosphere or magnetosphere will quickly spread along a field line and exist down to some lower height limit [Bernhardt and Park, 1977]. Bernhardt and Park calculate a lower height for the foot of the duct of about'300 km at night and above t 800 km for the day during winter and near the equinoxes; their termination height in summer is above t eeo km at all local times.…”

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confidence: 99%

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The formation of ducts and spread F and the initiation of bubbles by field‐aligned currents

Muldrew¹

1980

J. Geophys. Res.

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Magnetospheric ducts for medium frequency (MF) radio waves are formed, for L •> 1.2, between about 20 and 22 hours local time. Their occurrence frequency remains constant for the remainder of the night and begins to decrease after sunrise. This decrease continues until near sunset. The seasonal and longitudinal variation of the ducts and of low-latitude spread F implies that both are related to hemispheric asymmetry of the winds in the dynamo region and hence are probably generated by field-aligned currents as suggested by K. D. Cole. These currents generate significant irregularities in the E region of the ionosphere at night when E region densities are low; these irregularities in turn produce perpendicular electric fields due to winds. The small-scale electric fields (•< few kilometers) responsible for ducts can only be transferred to the F region and magnetosphere along magnetic field lines when the parallel conductivity is fairly large between the E and F layers. These electric fields interchange tubes of flux and hence can change tube densities. The transfer of electric fields occurs before the formation of the deep E- F density valley. The valley forms about 22 hours, which explains why ducts with L •> 1.2 can only form after the E region has low density (after 19 hours) and before the E-F valley forms. For L <• 1.2 the percentage occurrence of MF ducts increases from about 20 to roughly 02 hours local time and decreasesfrom roughly 02 to about 10 hours. It is thought that these ducts are associated with ionospheric 'bubbles.' The frequency of occurrence of MF ducts with L •< 1.2 continues to increase for roughly 3 hours after the frequency of occurrence of ducts with L •> 1.2 stops increasing. Since the estimated rise time for bubbles from the bottom of the F layer to the topside is about 3 hours, these ducts may also have been initiated before about 22 hours. INTRODUCTION Medium frequency (MF) radio waves transmitted by topside sounder satellites can become trapped in magnetic-fieldaligned ionization ducts. Observations of the traces on topside ionograms, resulting from the trapped waves, enable characteristics of the ducts to be determined [Muldrew, 1963, 1967a; Loftus et al., 1966; Dyson, 1967; Ramasastry, 1971; Nishizaki and Matuura, 1972; $harma and Muldrew, 1973, 1975]. The ionization ducts observed with the topside sounders have a diameter of about one to a few kilometers and an electron density deviation from ambient of the order of 1%. The occurrence of ducts is either independent of Kp or has a slight negative correlation. Whistler ducts are much larger and have been studied by Ondoh [1976]. MF ducts are closely related to ionization irregularities, i.e., to spread F[Calvert and $chmid, 1964; Dyson, 1968, 1977] and ionospheric bubbles [Dyson and Benson, 1978]. Bubbles have recently received much study [Woodman and La Hoz, 1976; Kelley et al., 1976; McClure et al., 1977; Ossakow and Chaturvedi, 1978; Ott, 1978].It has been suggested that ionospheric and magnetospheric field-aligned irregularities...

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Section: I/r---1/n Dn/ds (1)mentioning

confidence: 99%

mentioning

confidence: 99%

The formation of ducts and spread F and the initiation of bubbles by field‐aligned currents

Muldrew¹

1980

J. Geophys. Res.

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“…The sudden-commencement storms show an increased frequency at new moon [Bigg, 1963c]. Barrels [1963] shows that the conclusions stated in paragraph 3 are questionable, since randomizing the data yields variations of size comparable to those in the lunar data.…”

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confidence: 86%

Variations of geomagnetic activity with lunar phase

Stolov¹,

Cameron²

1964

J. Geophys. Res.

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“…The lunar effects controversy referred to above was initiated by the work of Bigg [1963a], but there was widespread interest at the time in published studies that purported to show associations between lunar phase and geophysical phenomena. If earlier work by Sucksdorff [1956] is included, a total of twelve articles ultimately appeared containing data and arguments that supported the hypothesis that the moon could influence geomagnetic activity [Sucksdorff, 1956; Bigg, 1963aBigg, , b, 1964Defouw, 1964, 1966a, b, c;Stolov and Cameron, 1964;$tolov, 1965;Benoit and Guez, 1966;Guez, 1966], and five articles appeared in which it was argued that the reported variations were due to chance or a combination of chance and solar influence [Bartels, 1963;Davidson and Martyn, 1964…”

Section: Introductionmentioning

confidence: 99%

Is there an increase of geomagnetic activity preceding total lunar eclipses?

Fraser–Smith¹

1982

J. Geophys. Res.

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The possibility that there is a lunar modulation of geomagnetic activity around the time of total lunar eclipses is investigated. The modulation of activity, as seen in the Ap indices for the years 1932–1980, consists of a 4‐day increase starting 3 days before the eclipse day. This characteristic of the modulation suggests that it may be caused by entry of the moon into the magnetospheric tail and by the subsequent motion of the moon within the tail; it is not observed in conjunction with partial lunar eclipses. By using the aa indices, which are available back to 1868, it is possible to study the long‐term temporal characteristics of the modulation. It is found that the increase in activity after 1932 is not replicated in the data prior to 1932 (during the years 1870–1931), and it is concluded that the increase is most probably a statistical anomaly and that it would be inappropriate to conclude from it that the moon's entry into the geomagnetic tail enhances geomagnetic activity.

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Behauptete Einfl�sse des Mondes auf die erdmagnetische Unruhe und ihr statistischer Hintergrund

Cited by 9 publications

References 5 publications

The formation of ducts and spread F and the initiation of bubbles by field‐aligned currents

The formation of ducts and spread F and the initiation of bubbles by field‐aligned currents

Variations of geomagnetic activity with lunar phase

Is there an increase of geomagnetic activity preceding total lunar eclipses?

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