unique characteristics of the sun corona

Giant super-tornados may also play a role in heating the sun's outer layer. Millions of them are going off every second across the sun, and collectively they heat the corona.' 'Despite being tiny by solar standards, each packs the wallop of a 10-megaton hydrogen bomb. 'The explosions are called nanoflares because they have one-billionth the energy of a regular flare,' Jim Klimchuk, a solar scientist at NASA's Goddard Space Flight Center in Maryland, said in a statement. Research suggests that tiny explosions known as nanoflares may help push the temperature up by providing sporadic bursts reaching up to 18 million F (10 million C). When you're roasting a marshmallow you move it closer to the fire to cook it, not farther away.' 'Things usually get cooler farther away from a hot source. 'That's a bit of a puzzle,' Jeff Brosius, a space scientist at Catholic University in Washington, D.C., and NASA's Goddard Space Flight Center in Greenbelt, Maryland, said in a statement. Why the corona is up to 300 times hotter than the photosphere, despite being farther from the solar core, has remained a long-term mystery. As the gases cool, they become the solar wind. Temperatures in the sun's corona can get as high as 3.5 million degrees F (2 million degrees C). It appears as white streamers or plumes of ionized gas that flow outward into space. Like the chromosphere, the sun's corona can only be seen during a total solar eclipse (or with NASA's Solar Dynamics Observatory). The third layer of the sun's atmosphere is the corona. 248, 256–262 (1991).The third layer of the sun's atmosphere is the corona. Interplanetary Dynamical Process (Interscience, New York, 1963). in Wave Propagation in Random Media (Scintillation) (eds Tatarskii. I estimate the size of the smallest filamentary structure within coronal holes to be about 1km at the Sun, approximately three orders of magnitude smaller than the smallest filamentary structures observed in images of different wavelengths 2,10–12. Here I argue that these features are the manifestation of a transition from small ray-like or filamentary structures in the corona that rotate with the Sun to turbulent density irregularities convecting with the solar wind. Two specific features that have proved difficult to explain are an abrupt increase in anisotropy of the irregularities close to the Sun 5–7, and a break in the power-law spectrum describing the density fluctuations 8,9. Radio measurements have established many of the characteristics of the density fluctuations in the corona and solar wind, but the fundamental nature of these structures is not yet fully understood 3,4. The structure can be investigated directly by imaging at optical and shorter wavelengths, or indirectly through the effects of changing electron density on the propagation of radio waves (scattering and scintillation). KNOWLEDGE of the structure of the Sun's corona is important for our understanding of how this high-temperature plasma is heated, and of the processes involved in the acceleration of the solar wind 1,2.

Unique characteristics of the sun corona