All Topics  
Interplanetary Magnetic Field

 

 
   Email Print
   Bookmark   Link
 

 

Interplanetary Magnetic Field
 
 
  Topics Interplanetary Magnetic Field Topic Home

The Interplanetary Magnetic Field (IMF) is the term for the Sun
Sun

The Sun , a G V star, is the star at the center of the Solar System. The Earth and other matter orbit the Sun, which by itself accounts for about 98.6% of the Solar System's mass....
’s magnetic field
Magnetic field

A magnetism field is a vector field which can exert a magnetic force on moving electric charges and on magnetic dipoles . When placed in a magnetic field, magnetic dipoles tend to align their axes parallel to the magnetic field....
 carried by the solar wind
Solar wind

The solar wind is a Electric current—a Plasma —ejected from the stellar atmosphere of the sun. It consists mostly of electrons and protons with energies of about 1 electron volt....
 among the planet
Planet

A planet , as 2006 definition of planet by the International Astronomical Union , is a celestial body orbiting a star or Stellar evolution#Stellar remnants that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared the neighbourhood of planetesimals....
s of the Solar System
Solar System

The Solar System consists of the Sun and those Astronomical object bound to it by gravity: the eight planets and five dwarf planets, their 173 known Natural satellite, and billions of Small Solar System body....
.

Since the solar wind is a plasma
Plasma (physics)

In physics and chemistry, plasma is a partially ionized gas, in which a certain proportion of electrons are free rather than being bound to an atom or molecule....
, it has the characteristics of a plasma
Magnetohydrodynamics

Magnetohydrodynamics is the academic discipline which studies the dynamics of electrical conduction fluids. Examples of such fluids include Plasma , liquid metals, and Brine....
, rather than a simple gas
Gas

In physics, a gas is a state of matter, consisting of a collection of particles without a definite shape or volume that are in more or less random motion....
. For example, it is highly electrically conductive so that magnetic field line
Magnetic field

A magnetism field is a vector field which can exert a magnetic force on moving electric charges and on magnetic dipoles . When placed in a magnetic field, magnetic dipoles tend to align their axes parallel to the magnetic field....
s from the Sun are carried along with the wind. The dynamic pressure
Pressure

Pressure is the force per unit area applied to an object in a direction surface normal to the surface. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure....
 of the wind dominates over the magnetic pressure
Magnetic pressure

Magnetic pressure is an energy density associated with the magnetic field. It is identical to any other physical pressure except that it is carried by the magnetic field rather than kinetic energy of the gas molecules....
 through most of the solar system (or heliosphere
Heliosphere

The heliosphere is a bubble in outer space "blown" into the interstellar medium by the solar wind. Although electrically neutral atoms from interstellar space can penetrate this bubble, virtually all of the material in the heliosphere emanates from the Sun itself....
), so that the magnetic field is pulled into an Archimedean spiral
Archimedean spiral

The Archimedean spiral is a spiral named after the 3rd century BC Ancient Greece mathematician Archimedes. It is the locus of points corresponding to the locations over time of a point moving away from a fixed point with a constant speed along a line which rotates with constant angular velocity....
 pattern (the Parker spiral
Parker spiral

The Parker spiral is the shape of the Sun's magnetic field as it extends through the solar system. Unlike the familiar shape of the field from a bar magnet, the Sun's extended field is twisted into an arithmetic spiral by the magnetohydrodynamic influence of the solar wind....
) by the combination of the outward motion and the Sun's rotation.






Discussion
Ask a question about 'Interplanetary Magnetic Field'
Start a new discussion about 'Interplanetary Magnetic Field'
Answer questions from other users
Full Discussion Forum



Encyclopedia


The Interplanetary Magnetic Field (IMF) is the term for the Sun
Sun

The Sun , a G V star, is the star at the center of the Solar System. The Earth and other matter orbit the Sun, which by itself accounts for about 98.6% of the Solar System's mass....
’s magnetic field
Magnetic field

A magnetism field is a vector field which can exert a magnetic force on moving electric charges and on magnetic dipoles . When placed in a magnetic field, magnetic dipoles tend to align their axes parallel to the magnetic field....
 carried by the solar wind
Solar wind

The solar wind is a Electric current—a Plasma —ejected from the stellar atmosphere of the sun. It consists mostly of electrons and protons with energies of about 1 electron volt....
 among the planet
Planet

A planet , as 2006 definition of planet by the International Astronomical Union , is a celestial body orbiting a star or Stellar evolution#Stellar remnants that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared the neighbourhood of planetesimals....
s of the Solar System
Solar System

The Solar System consists of the Sun and those Astronomical object bound to it by gravity: the eight planets and five dwarf planets, their 173 known Natural satellite, and billions of Small Solar System body....
.

Since the solar wind is a plasma
Plasma (physics)

In physics and chemistry, plasma is a partially ionized gas, in which a certain proportion of electrons are free rather than being bound to an atom or molecule....
, it has the characteristics of a plasma
Magnetohydrodynamics

Magnetohydrodynamics is the academic discipline which studies the dynamics of electrical conduction fluids. Examples of such fluids include Plasma , liquid metals, and Brine....
, rather than a simple gas
Gas

In physics, a gas is a state of matter, consisting of a collection of particles without a definite shape or volume that are in more or less random motion....
. For example, it is highly electrically conductive so that magnetic field line
Magnetic field

A magnetism field is a vector field which can exert a magnetic force on moving electric charges and on magnetic dipoles . When placed in a magnetic field, magnetic dipoles tend to align their axes parallel to the magnetic field....
s from the Sun are carried along with the wind. The dynamic pressure
Pressure

Pressure is the force per unit area applied to an object in a direction surface normal to the surface. Gauge pressure is the pressure relative to the local atmospheric or ambient pressure....
 of the wind dominates over the magnetic pressure
Magnetic pressure

Magnetic pressure is an energy density associated with the magnetic field. It is identical to any other physical pressure except that it is carried by the magnetic field rather than kinetic energy of the gas molecules....
 through most of the solar system (or heliosphere
Heliosphere

The heliosphere is a bubble in outer space "blown" into the interstellar medium by the solar wind. Although electrically neutral atoms from interstellar space can penetrate this bubble, virtually all of the material in the heliosphere emanates from the Sun itself....
), so that the magnetic field is pulled into an Archimedean spiral
Archimedean spiral

The Archimedean spiral is a spiral named after the 3rd century BC Ancient Greece mathematician Archimedes. It is the locus of points corresponding to the locations over time of a point moving away from a fixed point with a constant speed along a line which rotates with constant angular velocity....
 pattern (the Parker spiral
Parker spiral

The Parker spiral is the shape of the Sun's magnetic field as it extends through the solar system. Unlike the familiar shape of the field from a bar magnet, the Sun's extended field is twisted into an arithmetic spiral by the magnetohydrodynamic influence of the solar wind....
) by the combination of the outward motion and the Sun's rotation. Depending on the hemisphere
Earth

Earth is the third planet from the Sun. Earth is the largest of the terrestrial planets in the Solar System in diameter, mass and density. It is also referred to as the World and Wiktionary:Terra.Note that by International Astronomical Union convention, the term "Terra" is used for naming extensive land masses, rather...
 and phase of the solar cycle
Solar cycle

The solar cycle, or the solar magnetic activity cycle, is the main source of periodic solar variation driving variations in space weather....
, the magnetic field spirals inward or outward; the magnetic field follows the same shape of spiral in the northern and southern parts of the heliosphere, but with opposite field direction. These two magnetic domains are separated by a two current sheet
Current sheet

A current sheet is an electric current that is confined to a surface, rather than being spread through a volume of space. Current sheets feature in magnetohydrodynamics , the study of the behavior of electrically conductive fluids: if there is an electric current through part of the volume of such a fluid, magnetic forces tend to expel it f...
 (an electric current
Electric current

Electric current is the flow of electric charge. The electric charge may be either electrons or ions.The International System of Units unit of electric current intensity is the ampere....
 that is confined to a curved plane). This heliospheric current sheet
Heliospheric current sheet

The heliospheric current sheet is the surface within the Solar System where the magnet of the Sun's magnetic field changes from north to south....
 has a similar shape to a twirled ballerina
Ballerina

File:Corsaire -Le Jardin Anime -Mathilde Kschessinska & Olga Preobrajenska -1899.JPGA ballerina is a female ballet dancer; the male equivalent to this title is danseur or in some countries ballerino ....
 skirt, and changes in shape through the solar cycle as the Sun's magnetic field reverses about every 11 years.

The plasma
Plasma (physics)

In physics and chemistry, plasma is a partially ionized gas, in which a certain proportion of electrons are free rather than being bound to an atom or molecule....
 in the interplanetary medium
Interplanetary medium

The interplanetary medium is the material which fills the solar systems and through which all the larger solar system bodies such as planets, asteroids and comets move....
 is also responsible for the strength of the Sun's magnetic field at the orbit of the Earth being over 100 times greater than originally anticipated. If space were a vacuum, then the Sun's 10-4 tesla magnetic dipole field would reduce with the cube of the distance to about 10-11 tesla. But satellite observations show that it is about 100 times greater at around 10-9 tesla. Magnetohydrodynamic (MHD) theory predicts that the motion of a conducting fluid (e.g. the interplanetary medium) in a magnetic field, induces electric currents which in turn generates magnetic fields, and in this respect it behaves like a MHD dynamo.

See also

  • Solar wind
    Solar wind

    The solar wind is a Electric current—a Plasma —ejected from the stellar atmosphere of the sun. It consists mostly of electrons and protons with energies of about 1 electron volt....
  • magnetosphere
    Magnetosphere

    A magnetosphere is a highly magnetized region around and possessed by an astronomical object. Earth is surrounded by a magnetosphere, as are the magnetized planets Mercury , Jupiter, Saturn, Uranus, and Neptune....