Storms from the Sun The Emerging Science of Space Weather (2002) / Chapter Skim
Currently Skimming:
5. Living in the Atmosphere of a Star
5. Living in the Atmosphere of a Star
Pages 75-92
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From page 75... ...
The key to space weather is the transformation of energy a transformation from magnetic energy ant! intense heat on the Sun to plasma energy in interplanetary space to magnetic and electrical energy around the Earth.
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From page 76... ...
The electrons basically "boil" off the atoms, leaving a gas of free electrons ant! atomic nuclei that are positively charged.
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From page 77... ...
In the core of the Sun, the pressure is 250 billion times more intense than what we experience at the surface of the Earth, the density is 10 times the density of goicI, ant! temperatures approach 16 million degrees Celsius (29 million degrees Fahrenheit)
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From page 78... ...
. Between the radiation zone and the visible surface of the Sun is the convection zone, where superheated gases rise from the interior like water boiling in a pot.
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From page 79... ...
Heliospheric Observatory, a joint satellite mission of the European Space Agency (ESA) and NASA, fount!
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From page 80... ...
In nature, electric currents produce magnetic fields, ant! changing magnetic fielcis produce electric currents.
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From page 81... ...
The area in these images is about 186,000 miles across, large enough to span 23 Earths. The Slinky-like formation of coronal loops was roiling at nearly 2.7 million degrees C
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From page 82... ...
"However, at speeds starting at 20,000 miles per hour at the surface and accelerating to over 2 million miles per hour, the solar wind grows much faster than grass." The expanding, speeding plasma of the solar wind races away from the Sun in all directions to fill the space between the planets. Each bubble of plasma rises from inside the Sun and carries an imprint of the magnetic field of the Sun embedded in a mix of ions and electrons and helium nuclei.
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From page 83... ...
our planet. Even though a mere fraction of the solar wind energy penetrates the magnetosphere uncler the worst of conditions, it's enough to cause global magnetic storms ant!
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From page 84... ...
FIGURE 9. Caused by intense magnetic fields emerging from the interior of the Sun, a sunspot appears to be dark when contrasted against the rest of the solar surface because it is slightly cooler than the rest of the visible surface.
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From page 85... ...
other space weather effects arounc! Earth, Space Age observations have shown that, as solar researcher Tom Bogcian of the High Altitucle Observatory, Bouicler, Coloraclo, puts it, "sunspots are more like symptoms than the disease itself." The active regions above sunspots (in the corona)
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From page 86... ...
Most of the particles are deflected by Earth's magnetic field and the atmosphere absorbs nearly all the harmful radiation, but flares still can have a crippling effect on space-based activities. The intense X rays from a solar flare travel to Earth at the speed of light, giving space weather watchers little time to react.
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From page 87... ...
Once you remove the net, the balloon shoots skyward. After observing how magnetic fields abut ant!
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From page 88... ...
, the magnetosphere gets a major jolt. The magnetic field!
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From page 89... ...
Though magnetospheric physicists have long puzzlecl over the mechanism that accelerates the particles insicle Earth's cavity, recent observations suggest that the Van Allen radiation belts act as a sort of cosmic particle accelerator. The two concentric rings of racliation have long been known to vary greatly but have often been represented for engineering purposes by average moclels (see Figure 10~.
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From page 90... ...
The outer belt is largely made up of electrons and protons caught up in Earth's field by the interaction of solar wind and the magnetosphere. The inner belt is a product of cosmic radiation, which bombards the upper atmosphere and splashes energized particles into the space around the planet.
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From page 91... ...
least unclerstooc! effect of space weather, the long-term variation of solar activity couicl influence the climate patterns of Earth on scales from clecacles to millions of years (Chapter 10~.
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