When Superstorm Plasmas and Earth's Magnetosphere Collide
05.29.08
A hotbed of activity, the sun is capable of making giant superstorms. When it does, the storms release plasma into the solar wind.
Large solar flares often blast material from the sun’s outer atmosphere, called the corona. These coronal mass ejections (CMEs) can spew billions of tons of plasma away from the sun and toward Earth at speeds faster than 1.5 million mph.
When plasma from a superstorm collides with Earth’s magnetosphere, the region surrounding Earth dominated by its magnetic field, the effects are felt here on Earth.
As plasma from a superstorm interacts with Earth’s magnetosphere, it can trigger spectacular displays of the Northern Lights, called auroras, interfere with communications between satellites and airplanes traveling near the North Pole, and interrupt global positioning systems and our power grid.
NASA scientists have uncovered new details about how plasma from superstorms interacts with Earth’s magnetosphere. Mei-Ching Fok, an astrophysicist at NASA’s Goddard Space Flight Center in Greenbelt, Md., and her team have created a computer model that evaluates contributions to magnetospheric pressure from the solar wind, polar wind, auroral wind, and plasmaspheric wind.
Their simulation of sources of superstorm plasmas found that energetic protons from the plasmasphere, a donut-shaped region of the inner magnetosphere, dominate the magnetosphere’s pressure during a superstorm’s main phase. Until now, scientists thought energetic protons from the solar wind most affected the magnetosphere.
“The surprising result of this model is that the magnetosphere’s main phase pressure [the magnetosphere’s pressure during a superstorm’s main phase] is dominated by energetic protons from the plasmasphere, rather than from the solar wind,” says Fok. She and her team will present their findings on May 29 at the American Geophysical Union conference in Ft. Lauderdale, Fl.
During space storms, the plasmasphere is squashed and pressurized by the solar wind, forming a long tail called the plasmaspheric plume. The plume particles are picked up and further energized by the solar wind. When they re-enter the magnetosphere, they supply the majority of energetic protons that affect the magnetosphere’s main phase pressure during a superstorm event.
Simulating the sources of superstorm plasmas will help scientists better understand superstorms and paves the way to predicting their impact on Earth. The details uncovered in the team’s model provide a new piece of the Sun-Earth puzzle.
Laura Layton
NASA's Goddard Space Flight Center
첫댓글 Thanks. but too much difficult . I have a bad headache right nowe. ㅎㅎ
오!~~~~