Engineering topics

Winge, C. R.

Publications and source records attributed to Winge, C. R..

2 records

NASA NTRS1977

Solar polar coronal hole - A mathematical simulation

The northern polar region of the sun was studied during July 1973 by Munro and Jackson through use of the white-light coronagraph and the X-ray photographs produced by the Skylab mission. They described the northern polar hole as nearly axisymmetric and gave the geometry and density distribution under this approximation. The present work gives quasi-radial approximation to the full magnetohydrodynamic equations for axisymmetric, polytropic solar wind flow to simulate this polar hole, with the benefit that model temperature and magnetic field intensities and distributions in this particular polar hole can be deduced. It is concluded that from 2 out to 5 solar radii the temperature varies only slightly with radius, but is larger near the center of the polar hole than at the edge. It is also found that the magnetic field intensity at 2 solar radii could be about 1 gauss at the center of the hole, decreasing toward the edge of the hole. If this is extrapolated to the surface, a field as high as 20 gauss is suggested.

Suess, S. T.↗

NASA NTRS1976

Field-aligned currents in the Jovian magnetosphere - Pioneer 10 and 11

Field-aligned currents, which are known to play an important role in the dynamics of the earth's magnetosphere, would also be expected to flow in the Jovian magnetosphere during magnetically active periods. Such currents are difficult to observe largely because of their limited spatial extent and intermittent nature, but on the Pioneer 11 inbound pass to Jupiter on day 336, 1800 GRT, near the L shell of Ganymede, the helium vector magnetometer recorded a structured perturbation with the characteristic signature of a field-aligned current. No analogous structure was found on a similar Pioneer 10 inbound pass (day 337, 1200 GRT). The perturbation could have been caused by turbulence with the wake of Ganymede through which the spacecraft was moving or the perturbation could represent the first observation of a Jovian substorm. The observations are discussed in terms of both models, and difficulties are examined.

Kivelson, M. G.↗