POLAR Provides First Experimental Documentation of Magnetic Reconnection. Reconnection, the fundamental process for transferring/exchanging energy in the universe, occurs near earth, at the sun, and at other star systems
Reconnection, the fundamental process for transferring/exchanging energy in the universe, occurs near earth, at the sun, and at other star systems
Magnetic reconnection is no longer just a theoretical construct with schematic illustrations
The Hydra, EFI and MFE instrument teams, using POLAR particle and field data are producing maps of the reconnection site
Discovery: The first experimental documentation that the process of collisionless magnetic connection works as theoretically foreseen and can be a quasi-stationary process
Reconnection region will wash over POLAR as compression occurs
Position of POLAR (red) with respect to reconnection region (yellow) is dynamic, both are moving.
Fingerprints of Collisionless Reconnection:Magnetic field geometry
Simulation based on theory
Theory predicts that the magnetic field strength, shown in color, should approach zero at the reconnection site.
The POLAR analysis resolves this expected magnetic field structure to a resolution approaching 1 km
At one point during the interaction, the magnetic field strength is comparable to uncertainty levels for the magnetometer
Superposed epoch image of reconnection site
Fingerprints of Collisionless Reconnection:The Electron Pressure “Ridge”
Simulation of electron pressure ridge
As material flows inward, particle density builds and the particles are heated. If the electrodynamics is to be steady, without resistivity, an electron pressure “ridge” will form at right angles to the inflowing material.
POLAR observes this high pressure of electrons along the direction separating the solar wind from the magnetosphere side
Superposed epoch image of electron pressure at reconnection site
Fingerprints of Collisionless Reconnection:Unmagnetized Electrons
Superposed epoch image of degree to which electrons are controlled by the magnetic field
POLAR Provides First ExperimentalDocumentation of Magnetic Reconnection