Aaron Albanez
Professor James Whitesell
CHEM 151
26 February 2014
Rewrite #2: Auroras
Auroras and the Aurora Borealis/Australis
Ever looked up into the sky, specifically at the North Pole region, and seen the
Aurora Borealis? Well did you also know that this name was also given to this wonder of
the world because of spectacular auroras? These lights are also visible in the South Pole,
but these lights are given the name the Aurora Australis. There are reasons why these
spectacles of color, light, and awe. This prime reason is because of the collisions that occur
with charged particles in the Sun’s atmosphere and the Nitrogen and Oxygen that is present
in Earth’s atmosphere.
The protons and electrons that come from the Sun during Solar Winds cause these
particles to reach out into the vast realm of outer space, along with these particles magnetic
field. Maybe add a picture of what these solar winds look like. Also add a picture and
explanation of the Aurora Borealis. Electrical currents that are able to pass through the
Sun’s surface are cause by the use of the magnetic fields caused by the charged protons and
electrons. Because of this, these solar winds can travel at very high speeds; speeds reaching
up to 1000 km per second, meaning that they can reach the Earth’s magnetic field in 1 or 2
days. The boundary where these two meet is the Earth’s magnetosphere, which is another
name for the magnetic field for the Earth. Imagine a soap bubble’s geometry that is changed
when it is blown onto a surface. In a way, this is the same idea with solar winds and the
magnetosphere. When the solar wind hits the magnetosphere, the magnetic field that is
facing the sun is compressed and altered. This can become a huge issue to the magnetic
field of the Earth because of how much effect this can cause to the Earth. The purpose of the
magnetic field of the Earth’s atmosphere is to protect the Earth from solar particles, which
are guided away from the Earth. That information about the side of the Magnetic Field of
the sides of the Earth are not that important in relevance to the report. Unfortunately, the
invisible eye does not easily see this phenomenon on the Earth’s magnetosphere. However,
when some of these solar particles are trapped on the Earth’s magnetic poles, these
northern and southern lights can be seen.
Solar Winds and Pressure from these Winds
The pressure that comes from these solar winds creates an electrical voltage, and
causes the electrons to move up the magnetic poles of the Earth. As more electrons
approach the poles, they force through the upper layer of the atmosphere, the ionosphere.
This is the region where solar particles and air molecules collide. These solar particles
cannot move around in any direction in the magnetic field, however, they can move parallel
to the magnetic field. When the collision of the charged particles and the electrical and
magnetic field collide, then these trapped particles move only in conjunction with the
magnetic field lines. The combination of these two factors allows for the solar wind to drag
the magnetosphere field and plasma along, which then energizes the plasma in the
magnetosphere, allowing it to respond by transmitting all the electrons and protons to the
upper atmosphere. These energies are then released, which then causes the aurora to
appear as curtains and/or rays, which is a process called reconnection. This constant
collision of solar particles with the atmosphere can be seen though the quick fluidity of
these curtain-like lights.
Atomic Spectra and Light Emission Color
The collision of a gas molecule and a solar molecule causes an electron from the gas
molecule to be sent to a higher energy. AS the electron returns to the ground state, the
photon is released and light is emitted from this process. Because of different wavelengths,
light emissions in terms of color on the spectra are seen differently. These colors also
depend on the atoms that are collided with the solar molecules and the altitude of these
atoms. Information on wavelength on the Atomic Spectra can be added to add more detail
on the colors seen by the auroras. At high altitudes, oxygen is the most common gas
molecule, and at low altitudes, oxygen and nitrogen are bombarded by solar molecules.
Although some auroras may exhibit colors such as white, pink or purple, these colors are
the not actual light emission color from oxygen and nitrogen molecules.
There are a combination of colors emitted by oxygen, which are red and green, and
nitrogen, which are blue and red.
The color of the light emitted is also dependent on the altitude, which explains the
red color of the upper region of the auroras due to oxygen being sparsely distributed.
When a solar molecule collides with oxygen, the excited electrons returns to its ground
state in ¾ of a second to emit a green photon. To emit red photon, the same procedure
occurs, but it takes two minutes to emit this color. During this time of course, the collision
with another air particle might occur and covert energy to the other particle. Because
collisions between atmospheric and solar molecules are rare at high altitudes, the emission
of red light is visible at above 150 miles above the Earth’s surface. Above this altitude emits
a green light, while lower altitudes emit a purple light. Oxygen is prevented from emitting
photons at this altitude. Explain why in terms of the other molecules and the process itself.
When solar molecules collide with lighter molecules such as hydrogen and helium, they
emit blue and purple colors, and these can only be seen though high quality photographs.
Very interesting piece of information, but explain why these can only be seen though high
quality photographs.
As previously stated in this report, the auroras can be seen in both the North Pole
and the South Pole. The energetic particles that collide with the magnetic field that
surround the Earth have no preference towards which pole to congregate in. Why? In order
to see these auroras, the sky visibility and enough darkness must be present in order to be
seen only in the spring or fall. Only the hours around midnight is the time frame in which
these auroras can be seen. Aurora lights can be described as light emitting and flowing
throughout the sky as if it were in water. The rapid movement may look like a spiral of
curtains with curls or rays. During intense solar activity, the solar winds can bring out
more of the brightness of the aurora, and is some cases; they have been known to become
sub storms, which last about 30 to 90 minutes. What are sub storms and how are they
important? A slow expansion occurs with the aurora shape, and then, the aurora suddenly
brightens and fills the entire sky in a matter of seconds, with curtain-like rapid movements.
Sub storms disturb the magnetic field and are so strong that these solar winds can decrease
the magnetic field strength of the magnetosphere. Not only is the magnetic field affected,
but the atmosphere is also affected, but only at high altitudes. Solar wave particles also heat
and cause the ionization of the atmosphere, which increases electrical flow. Current in the
charged particles flow within the magnetosphere and ionosphere, and increase the heat of
the gas in the atmosphere at altitudes were auroras are found. Convection then occurs in
the atmosphere. What is convection? If not mentioned before, make a clearer indication of
this piece of information. Along with this phenomenon, wind speed increases to speeds as
fast as 1000 mph. Luckily, these effect do not occur near Earth’s surface to cause potential
harm, although research is being conducted to analyze long term effects of the climate
change cause by auroras.
Auroras and Magnetic Fields
Effects of electrons colliding with molecules in the atmosphere result in visible light
emitted. Though it may seem that electrons are the sole molecules partaking in the
phenomenon, photons also release a certain type of aurora that varies from the typical
curtains or rays caused by electrons. The shape is caused by restrictions of the magnetic
field that electrons flow in. In an atmosphere with many charged particles, these two
subatomic molecules are bound to collide, and when they do, a hydrogen atom is created.
The neutral hydrogen atom causes it to no longer be bound by the magnetic field line.
However, the proton can undergo collisions and thus become a proton once again and
spread throughout the atmosphere and create a “diffuse glow”, which cannot be physically
seen due to the spread out path.
There certain auroras are not just found on Earth, but can be spread out throughout
various planets in the solar system that have an atmosphere that can produce these
auroras. In the case where some planets do not have any magnetic fields, they have
magnetotails instead. In an article written about Venus, it was discovered that the solar
wind from the sun could react with ions in the ionosphere creating a “Magnetic plasma
bubble”. This phenomenon exhibited the process known as magnetic reconnection, though
it has a slightly different process in its inception. Auroras in Venus and look irregular and
seem dim compared to other planets that do have a magnetic field. Of all the magnetic fields
in the solar system, Saturn and Jupiter have the strongest magnetic fields, which means
that their magnetospheres can contain massive amounts of electrical current with rapid
speeds and plasma. Due to coupling of the ionosphere and magnetic sphere, there is a
slower rotational speed. As the magnetic lines attempt to increase plasma speed, they bend
and create a large flow of electricity though magnetosphere and ionosphere. Powerful
currents create auroras around each magnetic pole and are bight enough to be seen from
Earth. Mars, Mercury, and Uranus are among other planets that can experience this same
phenomenon as seen with Jupiter and Saturn. With majority of the information used in this
section of the report, it would work better if the information was condensed to make it
easier to understand. Too much unnecessary information provided.
Conclusion
Auroras truly are a spectacle to be seen and are unlike any other otherworldly
phenomenon that can be observed from Earth. Although this phenomenon is something to
behold, many processes must occur for these moving curtains of lights to appear in the sky,
including the release of massive energy from the sun, which alters the atmosphere by
modifying the magnetic fields of not only the Earth, but also other planets that contain one.
The colors and shapes seen are by electrons and protons from the Sun bombarding
molecules in the atmosphere and depend on solar wind collision; different wavelengths
emitted, and create a palate of various colors in the night sky. Although they are diffuse and
discrete, it displays the Sun’s powerful effect on the Earth and it’s atmosphere.