NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Back to Results
Magnetic clouds, helicity conservation, and intrinsic scale flux ropesAn intrinsic-scale flux-rope model for interplanetary magnetic clouds, incorporating conservation of magnetic helicity, flux and mass is found to adequately explain clouds' average thermodynamic and magnetic properties. In spite their continuous expansion as they balloon into interplanetary space, magnetic clouds maintain high temperatures. This is shown to be due to magnetic energy dissipation. The temperature of an expanding cloud is shown to pass through a maximum above its starting temperature if the initial plasma beta in the cloud is less than 2/3. Excess magnetic pressure inside the cloud is not an important driver of the expansion as it is almost balanced by the tension in the helical field lines. It is conservation of magnetic helicity and flux that requires that clouds expand radially as they move away from the Sun. Comparison with published data shows good agreement between measured cloud properties and theory. Parameters determined from theoretical fits to the data, when extended back to the Sun, are consistent with the origin of interplanetary magnetic clouds in solar filament eruptions. A possible extension of the heating mechanism discussed here to heating of the solar corona is discussed.
Document ID
19960021314
Acquisition Source
Jet Propulsion Laboratory
Document Type
Conference Paper
Authors
Kumar, A.
(Johns Hopkins Univ. Baltimore, MD United States)
Rust, D. M.
(Johns Hopkins Univ. Laurel, MD United States)
Date Acquired
August 17, 2013
Publication Date
June 30, 1995
Publication Information
Publication: International Solar Wind 8 Conference
Subject Category
Solar Physics
Accession Number
96N24710
Distribution Limits
Public
Copyright
Work of the US Gov. Public Use Permitted.

Available Downloads

There are no available downloads for this record.
No Preview Available