Professor Umran S. Inan

Winter 1999-00

Date: Wednesday, January 19, 2000
Time: 4:15-5:30 PM; Refreshments at 4:00 PM
Location: 380-380X

Observations in the Polar Cusp: Implications for Magnetic Reconnection

Dr. Steve Fuselier
Lockheed Martin Advanced Technology Center


Magnetic reconnection is a process whereby magnetic field lines from two different plasma regimes diffuse into a region (called the diffusion region) and interconnect. Once interconnected, the plasmas from the two regimes are able to co-mingle. One of the by-products of this diffusion and interconnection is the transfer of energy from the magnetic field to the plasma that is on interconnected magnetic field lines. By observing this plasma energization at the Earthıs magnetopause, reconnection has become the only process of mass, energy, and momentum transfer that has been unequivocally identified at this magnetospheric boundary.

Another magnetospheric region where the effects of magnetic reconnection are readily observable is in the Earthıs polar cusps. In these regions, global effects of reconnection are more evident than at a single observation point at the magnetopause.

This seminar begins with the introduction of the concept of magnetic reconnection in general and reconnection at the Earthıs magnetopause in particular. Observations in the polar cusps will be used to illustrate a current controversy concerning important details of magnetic reconnection. Resolution of this controversy will address a fundamental question of magnetic reconnection: Under what conditions do magnetic field lines from two different plasma regimes interconnect?