Charged Particle Motion in Earth's Magnetosphere

High-latitude Ionosphere

The magnetosphere not only supplies energetic particles that cause the aurora, but it also drives strong winds and electric currents in the high-latitude ionosphere and thermosphere.

Animation courtesy the COMET and HAO programs at UCAR/NCAR.

The magnetospheric convection that carries plasma and magnetic field from the dayside magnetopause into the magnetotail and back again also stirs winds in the high latitude ionosphere and thermosphere. These winds circulate from the dayside auroral ovals across the polar caps to the night side, then around the dawn and dusk sides back to the dayside.

Animation courtesy the COMET and HAO programs at UCAR/NCAR.

In the lower part of the ionosphere, from about 80 to 150 kilometers, the electric field associated with the magnetosphere-ionosphere circulation drives strong horizontal electric currents.

Electrical currents in the E-region of the ionosphere

Because of the peculiar nature of ionospheric conductivity, there are actually two high-latitude current systems. One system comprises Hall currents, which flow perpendicular to both the electric and magnetic fields and are strongest near 105 kilometers altitude. The other system is made up of Pedersen currents, which flow perpendicular to the magnetic field and parallel to the electric field and are strongest near 125 kilometers altitude. These two ionospheric current systems connect via field-aligned currents to the magnetospheric current system.

Hall, Pedersen, and Field-aligned currents in the polar ionosphere

Last modified May 17, 2005 by Randy Russell.

You might also be interested in:

Cool It! Game

Check out our online store - minerals, fossils, books, activities, jewelry, and household items!...more

Space Weather Causes Currents in Electric Power Grids

Space weather causes electricity to flow in our atmosphere. Sometimes that electricity lights up the sky! It causes the aurora (the Southern and Northern Lights). The electric currents in the atmosphere...more

Charged Particle Motion in Earth's Magnetosphere

Motions within Earth's metallic core generate the planet's global magnetic field. This magnetic field extends beyond Earth's surface and atmosphere into the space surrounding our home planet. The interaction...more


Altocumulus clouds are part of the Middle Cloud group. They are grayish-white with one part of the cloud darker than the other. Altocumulus clouds usually form in groups. Altocumulus clouds are about...more


Altostratus clouds belong to the Middle Cloud group. An altostratus cloud usually covers the whole sky. The cloud looks gray or blue-gray. The sun or moon may shine through an altostratus cloud, but will...more


Cirrocumulus clouds belong to the High Cloud group. They are small rounded puffs that usually appear in long rows. Cirrocumulus are usually white, but sometimes appear gray. Cirrocumulus clouds are the...more


Cirrostratus clouds belong to the High Cloud group. They are sheetlike thin clouds that usually cover the entire sky. The sun or moon can shine through cirrostratus clouds. When looking at the sun through...more


Cirrus clouds are the most common of the High Cloud group. They are made of ice crystals and have long, thin, wispy streamers. Cirrus clouds are usually white and predict fair weather. ...more

Windows to the Universe, a project of the National Earth Science Teachers Association, is sponsored in part is sponsored in part through grants from federal agencies (NASA and NOAA), and partnerships with affiliated organizations, including the American Geophysical Union, the Howard Hughes Medical Institute, the Earth System Information Partnership, the American Meteorological Society, the National Center for Science Education, and TERC. The American Geophysical Union and the American Geosciences Institute are Windows to the Universe Founding Partners. NESTA welcomes new Institutional Affiliates in support of our ongoing programs, as well as collaborations on new projects. Contact NESTA for more information. NASA ESIP NCSE HHMI AGU AGI AMS NOAA