The Heliospheric Magnetic Field, the Solar Wind & the Interstellar Medium
Jun. 19 & 20
NASA Project Scientist for the Ulysses Mission The solar corona accelerates into space to form the supersonic solar wind and push the interstellar medium out of the solar system to distances beyond 100 AU creating the Heliosphere. It also carries the Sun's dipole magnetic field into the Heliosphere filling it with magnetized plasma. The Heliospheric Magnetic Field (HMF) prevents the interstellar plasma and magnetic field from penetrating into the Heliosphere leading to a sharp boundary separating solar and interstellar plasmas. The magnetic dipole is tilted to the Sun's rotation axis and, as the Sun rotates, fast and slow winds interact introducing internal structure and dynamics. Helisopheric dynamics are further enhanced by the penetration of some interstellar constituents into the Heliosphere, namely, neutral gas, electrically- charged interstellar dust and Galactic Cosmic Rays. The structure and dynamics of the heliosphere are profoundly affected by the changes in the solar magnetic field that cause the solar cycle. These physical phenomena will be reviewed based on 17 years of 3D observations by Ulysses, the first spacecraft in a polar orbit that passes above the Sun's polar caps.
Dr. Edward J. Smith
NASA Project Scientist, Ulysses Mission