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Wilcox, J. M.

Publications and source records attributed to Wilcox, J. M..

At least 109 records · Page 6
All sourcesNASA NTRSDOE OSTI
NASA NTRS1971

Interplanetary magnetic sector polarity inferred from polar geomagnetic field observations

In order to infer the interplanetary sector polarity from polar geomagnetic field diurnal variations, measurements were carried out at Godhavn and Thule (Denmark) Geomagnetic Observatories. The inferred interplanetary sector polarity was compared with the polarity observed at the same time by Explorer 33 and 35 magnetometers. It is shown that the polarity (toward or away from the sun) of the interplanetary magnetic field can be reliably inferred from observations of the polar cap geomagnetic fields.

Friis-Christensen, E.↗
NASA NTRS1971

Divers solar rotation

The rotational properties in the photospheric and solar wind plasma and magnetic fields are considered. In both the photosphere and the interplanetary medium near the earth, there is a tendency for the field patterns to rotate a few percent faster than the plasma patterns. The fields and plasmas show variability in their rotational properties on time scales of days or months, but averages over a few years tend to be less variable, as shown by the results for long-lived sunspots, and by the rotating solar magnetic dipole.

Wilcox, J. M.↗
NASA NTRS1971

The extended coronal magnetic field.

The coronal magnetic field should contain many field lines connecting the photosphere to interplanetary space. A sharp boundary separates two adjacent sectors of opposite polarity. The large-scale structure of the corona is related to the photospheric sector pattern. The corona may frequently contain transient magnetic loops reaching out to five to ten solar radii.

Wilcox, J. M.↗
NASA NTRS1971

Five-minute oscillations in the solar magnetic field.

Evidence for the existence of 5 min oscillations in the photospheric and low chromospheric magnetic fields is presented, their properties discussed, and a possible production mechanism suggested. It is pointed out that, because the solar magnetic field is frozen into the oscillating plasma, there are several ways in which the oscillations in the plasma (which are observed as velocity oscillations) could be transferred to the magnetic field. It is shown schematically how vertical waves could cause oscillations in a horizontal magnetic field, and how horizontal waves could cause oscillations in a vertical magnetic field.

Tanenbaum, A. S.↗
NASA NTRS1971

Sector structure of the solar magnetic field.

Analysis of the solar sector structure, which consists of a boundary in the north-south direction such that on one side of the boundary the large-scale weak photospheric magnetic field is predominantly directed out of the sun, and on the other side of the field this boundary is directed into the sun. The region westward of a solar sector boundary tends to be unusually quiet and the region eastward of a solar sector boundary tends to be unusually active. The tendency is discussed with reference to flares, coronal enhancements, plage structure, and geomagnetic response.

Wilcox, J. M.↗