The Interplanetary Magnetic Field (Parker Spiral)
The Interplanetary Magnetic Field (Parker Spiral)
This Demonstration shows the configuration of the interplanetary magnetic field (IMF) that originates in the Sun and is carried into space by the solar wind. The plots are based on the Parker model of the solar wind (see The Solar Wind Demonstration). The Sun's rotation causes the magnetic field streamlines to assume a spiral shape, also known as the Parker spiral. Four arms with different orientation (phase angles) in the ecliptic plane are plotted. You can vary the velocity of the solar wind flow, which is assumed to be constant. Distance is expressed in astronomical units (1 a.u. is the mean distance between the Earth and the Sun). The innermost circle represents the orbit of Mercury. The second, thicker circle represents the Earth's orbit, while the two subsequent circles are the orbits of Mars and Jupiter, respectively. The second image is a 3D plot of the IMF for a radial velocity of 300 km/s.