The Heliospheric Magnetic Field

  title={The Heliospheric Magnetic Field},
  author={Mathew J. Owens and Robert J. Forsyth},
  journal={Living Reviews in Solar Physics},
The heliospheric magnetic field (HMF) is the extension of the coronal magnetic field carried out into the solar system by the solar wind. It is the means by which the Sun interacts with planetary magnetospheres and channels charged particles propagating through the heliosphere. As the HMF remains rooted at the solar photosphere as the Sun rotates, the large-scale HMF traces out an Archimedean spiral. This pattern is distorted by the interaction of fast and slow solar wind streams, as well as… 
This paper provides insight into heliospheric processes and galactic cosmic ray (GCR) modulation occurring due to the presence of two branches of solar activity in this solar layer. According to the
A Study of Heliospheric Modulation and Periodicities of Galactic Cosmic Rays During Cycle 24
Galactic cosmic rays (GCRs) are energetic, charged particles coming from outside the solar system. These particles encounter an outward-moving turbulent solar wind with cyclic magnetic-field
Impact of solar magnetic field amplitude and geometry on cosmic rays diffusion coefficients in the inner heliosphere
Cosmic rays are remarkable tracers of solar events when they are associated with solar flares, but also galactic events such as supernova remnants when they come from outside our solar system. Solar
Generation of Inverted Heliospheric Magnetic Flux by Coronal Loop Opening and Slow Solar Wind Release
In situ spacecraft observations provide much-needed constraints on theories of solar wind formation and release, particularly the highly variable slow solar wind, which dominates near-Earth space.
An analysis of heliospheric magnetic field flux based on sunspot number from 1749 to today and prediction for the coming solar minimum
It is now well established that many bulk properties of the solar wind rise and fall with the solar cycle, and the heliospheric magnetic field (HMF) intensity is no exception. The HMF intensity is
The heliospheric magnetic flux, solar wind proton flux, and cosmic ray intensity during the coming solar minimum
Recent papers have linked the heliospheric magnetic flux to the sunspot cycle with good correlation observed between prediction and observation. Other papers have shown a strong correlation between
(Non)radial Solar Wind Propagation through the Heliosphere
The solar wind nonradial velocity components observed beyond the Alfvén point are usually attributed to waves, the interaction of different streams, or other transient phenomena. However,
Estimating the Open Solar Flux from In-Situ Measurements
A fraction of the magnetic flux threading the solar photosphere extends to sufficient heliocentric distances that it is dragged out by the solar wind. Understanding this open solar flux (OSF) is
Modulation of UK lightning by heliospheric magnetic field polarity
Observational studies have reported solar magnetic modulation of terrestrial lightning on a range of time scales, from days to decades. The proposed mechanism is two-step: lightning rates vary with
Comets as natural laboratories: Interpretations of the structure of the inner heliosphere
Comets can be considered to be natural laboratories of the inner heliosphere, as their ion tails trace the solar wind flow. Much has been learnt about the heliosphere’s structure from in situ solar


The Heliospheric Magnetic Field
The Heliospheric Magnetic Field (HMF) is the physical framework in which energetic particles and cosmic rays propagate. Changes in the large scale structure of the magnetic field lead to short- and
The global heliospheric magnetic field
The heliospheric magnetic field originates on the Sun. Portions of the solar field extend up into the corona, the Sun’s outermost atmosphere, where the solar wind originates. The perfectly
Photospheric and heliospheric magnetic fields
The magnetic field in the heliosphere evolves in response to the photospheric field at its base. This evolution, together with the rotation of the Sun, drives space weather through the continually
The Heliospheric Magnetic Field and Its Extension to the Inner Heliosheath
The general structure of the heliospheric magnetic field is well known and has been extensively studied, mostly in the inner heliosphere, out to the orbit of Saturn. Beyond 10 AU, the Pioneer and now
Solar origin of heliospheric magnetic field inversions: Evidence for coronal loop opening within pseudostreamers
The orientation of the heliospheric magnetic field (HMF) in near‐Earth space is generally a good indicator of the polarity of HMF foot points at the photosphere. There are times, however, when the
Direct observational evidence for a heliospheric magnetic field with large excursions in latitude
Fisk has pointed out that the heliospheric magnetic field in fast solar wind, that is, at the higher heliographic latitudes, may undergo large excursions in heliographic latitudes, and thus that the
Heliospheric Modulation of Galactic Cosmic Rays During Solar Cycle 23
Galactic cosmic rays (GCRs) encounter an outward-moving solar wind with cyclic magnetic-field fluctuation and turbulence. This causes convection and diffusion in the heliosphere. The GCR counts from
An atlas of photospheric magnetic field observations and computed coronal magnetic fields: 1976–1985
Daily magnetogram observations of the large-scale photospheric magnetic field have been made at the John M. Wilcox Solar Observatory at Stanford since May of 1976. These measurements provide a
Motion of the footpoints of heliospheric magnetic field lines at the Sun : Implications for recurrent energetic particle events at high heliographic latitudes
The interplay between the differential rotation of the footpoints of heliospheric magnetic field lines in the photosphere and the subsequent nonradial expansion of these same field lines with the
The structure and origin of magnetic clouds in the solar wind
Plasma and magnetic field data from the Helios 1/2 spacecraft have been used to investigate the structure of magnetic clouds (MCs) in the inner heliosphere. 46 MCs were identified in the Helios data