Estimated Electrical Power - Northern & Southern Auroral Ovals
The power levels shown here are estimated from observations made by NOAA/TIROS of high-velocity electrons and positive ions raining down over the auroral oval. These electrons are responsible for the auroral lights. All of the energy of these particles is eventually deposited into the Earth's upper atmosphere. However, the energy of these particles is only about 10-30% of the total energy flowing into the atmosphere along the auroral oval. The remainder is deposited by up to million-ampere electric currents as they heat the upper atmosphere. During times of high activity, the power deposited can easily exceed the sum of all the electrical power generated in the United States over the same time interval.
Southern Hemisphere
Ultraviolet image of Earth's upper atmosphere, showing auroral activity
This image was taken at ultraviolet wavelengths that are not directly visible to the human eye. The glow you see is from atomic oxygen atoms at altitudes between about 100 and 500 kilometers (60 to 300 miles). The intensity of the light is color-coded with dark red as lowest intensities and whitish yellow as the brightest intensities.
Images were acquired with the Earth Camera that is one of three cameras in the Visible Imaging System (VIS) which was designed and constructed at The University of Iowa. The VIS is one of twelve instruments on the Polar satellite of the NASA Goddard Space Flight Center. The Principal Investigator is Dr. L. A. Frank and the Instrument Scientist and Manager is Dr. John. B. Sigwarth.
Ultraviolet image of Earth's upper atmosphere, showing auroral activity
This is the current ultraviolet image of the Earth's auroral oval taken by the Ultraviolet Imager (called UVI) on the POLAR spacecraft. It is updated every 7 minutes while the POLAR spacecraft is in contact with ground stations on Earth. Bright features in the images are glowing regions of molecular nitrogen and atomic oxygen atoms at about 100-150 kilometers (60-90 miles) altitude. High energy collisions between these atoms and precipitating electrons in the aurora cause this glow. The oval is the imprint of a magnetic storm raging in the magnetosphere. The brighter and more active the emissions, the more severe the space weather disturbance.
Images were acquired with the Ultraviolet Imager on the POLAR spacecraft. The Principal Investigator is Dr. George Parks at the University of Washington. Picture of the Day is produced and maintained by Dr. Jim Spann at Marshall Space Flight Center.
Magnetospheric Response: Voltage Across the Polar Cap
This derived quantity provided by scientists from Rice University measures the solar wind energy input to the magnetosphere that drives magnetospheric convection. It appears as an electric potential imposed across the polar ionosphere. This estimate does not account for time delays such as those imposed by friction between the ionosphere and the neutral atmosphere.
