About Me - Milton Laene Araujo

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Lake Worth, Florida, United States
My name is Milton and I am a reader. I love to feed my mind with what if’s?, through stories.

6/15/11

Is this the beginning or is it the end?

When can I see you again? http://www.youtube.com/watch?v=4_TzIUlaQok

In reality we all talk about the end, but little we know about science to have a firm position. Let me share with you a few topics.

A solar flare is a sudden brightening observed over the Sun surface or the solar limb, which is interpreted as a large energy release of up to 6 × 1025 joules of energy[1] (about a sixth of the total energy output of the Sun each second). The term is also used to refer to similar phenomena in other stars, where the term stellar flare applies.
Solar flares affect all layers of the solar atmosphere (photosphere, chromosphere, and corona), when the medium plasma is heated to tens of millions of kelvins and electrons, protons, and heavier ions are accelerated to near the speed of light. They produce radiation across the electromagnetic spectrum at all wavelengths, from radio waves to gamma rays, although most of the energy goes to frequencies outside the visual range and for this reason the majority of the flares are not visible to the naked eye and must be observed with special instruments. Flares occur in active regions around sunspots, where intense magnetic fields penetrate the photosphere to link the corona to the solar interior. Flares are powered by the sudden (timescales of minutes to tens of minutes) release of magnetic energy stored in the corona. The same energy releases may produce coronal mass ejections (CME), although the relation between CMEs and flares is still not well established.
X-rays and UV radiation emitted by solar flares can affect Earth's ionosphere and disrupt long-range radio communications. Direct radio emission at decimetric wavelengths may disturb operation of radars and other devices operating at these frequencies.
Solar flares were first observed on the Sun by Richard Christopher Carrington and independently by Richard Hodgson in 1859 [2] as localized visible brightenings of small areas within a sunspot group. Stellar flares have also been observed on a variety of other stars.
The frequency of occurrence of solar flares varies, from several per day when the Sun is particularly "active" to less than one every week when the Sun is "quiet", following the 11-year cycle (the solar cycle). Large flares are less frequent than smaller ones.
Solar flares impact Earth only when they occur on the side of the Sun facing Earth.  Because flares are made of photons, these travel out directly from the flare site, so if we can see the flare, we can be impacted by it.

The solar cycle is an average 11 year cycle where the number of sunspots goes from very few per month, to many, and back to very few.  At solar minimum, we might see no sunspots where at solar maximum, we can have 200 sunspots in a month.  Solar flares, coronal mass ejections and solar energetic particles all increase in frequency as we get closer to solar maximum.  High speed wind streams are more frequent at solar minimum, thus ensuring that space weather is something to watch for no matter where we are in the solar cycle.
"""Research to improve solar forecasting is occurring in two major areas. The first area is the correlation of observable
phenomena with effects on Earth. For example, we have observed a strong correlation between sunspot cycles and
disturbances on Earth. However, this correlation is very coarse; we know that during a certain period of years there will
be high levels of solar activity and the accompanying disturbances on Earth. But we cannot accurately predict these
disturbances as happening over specific days or hours, as we would like to be able to. Many researchers are trying to
refine the correlations between observable symptoms, like increased radio emission, and subsequent eruptions of
mass. Some of the best correlations yet are those that have been found between the evolution of sunspot groups and
eruptions."""


The second area of work is that of constructing a model for the Solar-Terrestrial environment. In addition to the
complexities of MHD, the problem is difficult because there are three different domains involved, which all couple
together. The first domain is that of the Sun; to simply construct a mathematical model of the Sun is far beyond us at the
present time. There are still many mysteries about what is going on inside the Sun, what triggers flares and even why
sunspots form. The second domain is the interplanetary medium, once thought of as empty space. This space is filled
with the solar wind plasma, which is not fully understood. The third domain is the geomagnetosphere, with its many
regions and currents. The magnetotail, extending for millions of kilometers out from Earth, has been difficult to study
directly and remains poorly understood. We are not close to having a model for any one of these domains by itself, yet
the final complication comes from the fact that these three domains are not at all separate. A change in one of these
domains can have major consequences on the surface of Earth; we hope one day to have a comprehensive model for the
entire solar-terrestrial environment but this is certainly a problem for physicists of the future.