IB Group 4 Project Notes
Research Question: How do solar flares affect human existence?
By Rabbas Roya and Sumaira, Taras and Brian
What Are Solar Flares?
A solar flare can be defined as a sudden, swift, and intense variation in brightness emitted by the Sun. Essentially, it is the sudden release of large amounts of magnetic energy built-up in the Sun’s corona (outermost atmosphere layer). Solar flares emit particles and rays due to the Sun’s brightness. The radiation emitted by solar flares is essentially the complete electromagnetic spectrum. The energy released is equivalent to that of 100-megaton hydrogen bombs and 1*1027 ergs or 1*1020 J per second. This magnetic energy includes particles such as electrons, protons, as well as portions of nuclei. This stream of charged particles is known as solar wind can reach up to temperature of 1 million degree Celsius and speeds of 900 km/s. Solar wind is composed of super-heated ionized gas known as plasma. A solar flare can be compared to ten million times superior to that of a volcanic eruption; but it constitutes only 10% of the total energy emitted by the Sun per second. All of the layers of the solar atmosphere are affected by solar flares, including the corona, chromospheres, and the photosphere.
From each active region, solar flares develop through three phases: precursor, impulsive, and decay. Each of these is discussed in greater detail below.
1. The Precursor Phase
In the precursor phase, the magnetic energy is released, which results in the release of soft x-ray emissions. These emissions are used by satellite telescopes to see the intensity of the corona while the solar flare is preparing to launch.
2. The Impulsive Phase
In the impulsive phase, atomic particles, such as protons, electrons, and nuclei are accelerated to energies that give them a charge of 1 MeV (Million electron Volts); this phase sees the release of stronger radioactive waves such as hard x-rays, gamma rays, and even radio waves.
3. The Decay Phase
The final phase, the decay phase, sees the gradual decomposition of the soft x-ray emissions, as they have small frequencies.
Solar flares occur in active regions or regions of strong magnetic fields. They expand to the outermost part of the Sun’s atmosphere (the corona) and contain extremely rarefied gas. The temperature inside a flare generally varies from ten to twenty million Kelvin and even 100 million in extreme cases. They appear loopy in shape and are found near the solar equator, the area of high magnetic field. Scientific instruments are used to detect the radiation signals that solar flares emit. Telescopes on earth can be used to view radio and optical emissions but x-rays and gamma rays require the use of telescopes in space. This is because such x-rays and gamma rays do not breach the atmosphere of the Earth. The frequency of solar flares parallel with the Sun’s eleven year cycle; when the solar cycle is at its least apparent, the active regions are rare and miniature. As the Sun moves towards its maximum part of the eleven year cycle, the solar flares are detected more often and more sunspots occur on the Sun.
According to the peak change, solar flares are typically categorized as A, B, C, M or X. These classes differ by a factor of ten with the X class of solar flares with a peak flux order of 1*10-4W/m2. The wide range of total energies results in the various magnitude orders, with the frequency of the flares generally inversely proportional to the total energy.
Solar cycles are 11-year intervals of periodic solar variations in which the Sun’s magnetic activity affects the radiation on Earth. These cycles are detected by the regularity and location of the sunspots appearing on the Sun. Typically, a solar function structures the Sun’s atmosphere, corona and wind, adapts the solar irradiance, modulates the flux of the radiations (short-wavelength), modulates the regularity of flare frequency, coronal mass ejections, and indirectly modulates the flux of galactic cosmic rays (high-energy) within the solar system.
The Causes of Solar Flares
A solar flare is essentially magnetic energy being released from the corona of the Sun. The reason the Sun has magnetic energy in it is because it is an electromagnet, like the Earth; it has a north pole and a south pole. These poles form magnetic fields around the Sun, which necessitate the need to release energy as the Sun is comprised of plasma, which is a superheated gas. In plasma the electrons move very fast; combined with the effects of magnetic charges on the electrons, it is inevitable that some magnetic energy needs to be released. This is because when the energy stored in the magnetic fields becomes too great, a slight brush of one magnetic field line to another causes the huge burst of magnetic energy known as a solar flare. This process is called magnetic reconnection.
There are two different types of flares: impulsive and gradual. The main difference between them is that impulsive flares accelerate mainly electrons, while gradual flares accelerate protons and ionized atoms as well. However, there are some releases of magnetic energy that can become coronal mass ejections. A coronal mass ejection is the Sun’s attempt at dieting, that is, it ejects the excess mass of plasma found in the corona. Coronal mass ejections usually take away some ten billion tons of superheated plasma away from the Sun. Unlike flares, which explode from the corona, a coronal mass ejection takes the form of a release of solar wind high above the Sun’s atmosphere.
Flares occur in every star, specifically at the corona. The corona is the outermost layer of a star’s atmosphere. Over the course of 11 years, the duration of a solar cycle, sunspots form on the corona. These are dark spots that are created by a high concentration of magnetic energy. These sunspots help form active regions on the corona, areas where solar flares are most likely to occur. The number of active regions is directly proportional to the number of sunspots on the corona.
The Importance of Solar Flares
The effects of a solar flare can range from negligible to catastrophic, depending on its size. Class A, B, and C flares are small in size and do not have much of an effect on humans. Class M and X are considered large flares and have the potential to catastrophically affect human existence.
Small Solar Flares
Small solar flares (classes A, B, and C) result in a level of radiation negligibly greater than the normal level associated with the Sun. In fact, class A flares are so small that it is impossible to tell them apart from the Sun’s usual emission of radiation without using very high-tech equipment. Small solar flares do not have a noticeable effect on Earth and are only significant in terms of their effect on the Sun, as they allow the Sun to get rid of excess magnetic energy which cannot be stored in a specific region of the Sun any longer.
Large Solar Flares
In contrast, large solar flares (classes M and X) can produce a large amount of radiation and particles, affecting the planets in orbit around the Sun. This can have a catastrophic affect on global telecommunications system, the health of astronauts, life on Earth, and the ozone layer. Each of these is discussed in greater detail below.
1. Effect on Global Telecommunications System
Although most solar flares typically last only a few minutes, the immense amount of particles and radiation they emit travels to Earth in about 8 minutes. This interferes with the Earth’s ionosphere, which is the uppermost part of the Earth’s atmosphere dependent on solar radiation. The increase in solar radiation brought forth by a solar flare can potentially cause sudden ionospheric disturbances (SID), which disturb the balance of negative free electrons and positive ions in the ionosphere by increasing ion density. When radio signals travel, especially long-distance radio signals, they reach this layer of the Earth’s atmosphere and are reflected, diffracted, and refracted, depending on the objects they encounter and the medium in which they travel. The global telecommunications system is designed so that when radio signals reach the ionosphere, they are reflected, refracted, and diffracted in such a way as to travel to particular receptors. If a solar flare occurs, however, the ionosphere has an increased number of protons (which count as objects), so there are more obstacles in a radio wave’s path. This can cause the wave to change directions, potentially resulting in a radio blackout. This affects a variety of forms of wireless communications, including two-way radio communications, general mobile radio communications, point-to-point radio communications, radio broadcasting, and GPS signals. Typically, the blackouts only last while the solar flare’s radiation is still reaching the Earth, after which time the radio signals return to normal. However, these blackouts could affect the quality of radio communications for a longer period of time.
In addition, the high intensity radiation and particle emissions can affect satellites in orbit around the Earth. Because of the enormous amounts of particles that reach the Earth, the Earth’s atmosphere expands to accommodate the increase of particles, particularly of ions in the ionosphere. This expansion enhances the drag on a satellite as it orbits the Earth, potentially changing the path of orbit (orbital). Usually, this does not significantly impact global telecommunications; however, it has the potential to be catastrophic by destroying satellites or veering them off course. Essentially, it could result in a destruction of the global communication system as we know it, which, in our technologically advanced age, would be an almost apocalyptic occurrence.
2. The Health of Astronauts
Solar flares are a source of deadly radiation, and radiation is extremely damaging to living cells. Astronauts are particularly susceptible to the effects of solar flares because they are not protected by the Earth’s atmosphere. Class M and X solar flares particularly cause harm to astronauts, with exposure causing vomiting, fatigue, and low blood counts. Without medical attention, this could lead to death. In extreme circumstances, the excess radiation can cause a break in the DNA of astronauts, which can develop into cancer, cataracts, and other maladies resulting from genetic mutations. Cells that reproduce rapidly, such as in the skin, the eyes, and in blood-forming organs, are the most susceptible to long-term damage because they cannot easily repair themselves while replicating, as most of their energy goes towards rapid reproduction. According to a study done by Cold Spring Harbour Laboratory (CSHL), increased levels of cosmic radiation also have the potential to damage stem cells in an astronaut’s brain.
This, however, is not as serious as it sounds, because it only impacts unprotected astronauts, or those protected only by a few inches of aluminum (which is what most portions of most space-crafts are made of). Solar activity is carefully monitored, so astronauts usually have enough of a warning to withdraw to better-protected areas of the spacecraft. However, as discussed earlier, solar flares have the potential to disrupt communications system, so astronauts might not receive the warning in time. There is therefore great need to develop countermeasures such as improved shielding and development of astronaut-particular medications. Radiation has been associated with cognitive disturbances, which have the potential to be particularly catastrophic for astronauts in space because of the nature of their work.
3. Life on Earth
The Earth’s magnetic field (magnetosphere) acts as an enormous protector against the shower of particles that comes along with a large solar flare. It sweeps aside the particles as they come cascading down on the planet, deflecting them to the north and south poles of the Earth, which then pushes them off into space. The particles that make it past the magnetic fields are absorbed by the Earth’s ionosphere (see section 1). However, if a solar flare is powerful enough, some of the radioactive particles cannot be fully deflected and absorbed by these two forces and make it to the Earth’s surface. There is no scientific indication that this could actually cause catastrophic harm to life on this planet (unlike the inaccurate depiction of solar flares in the recent Hollywood movie Knowing, which suggests that a large enough solar flare could heat up the Earth and cause it to be engulfed by all-destructive radiation and heat). The effects of immense ejections of radiation brought about by large solar flares are in fact negligible to biological systems on Earth.
However, there is a growing body of research that suggests that a geomagnetic storm, caused by disturbances in the Earth’s magnetosphere brought about by phenomena such as solar flares, can have adverse effects on biological systems. These include human, plant, and animal systems; however, not enough research has been done to suggest that the correlation between geomagnetic storms and changes in biological systems can be considered causation.
4. Climate Change and the Ozone Layer
If particles such as protons exist in large enough quantities, they do not stop only at the ionosphere when they bombard the Earth’s upper atmosphere. Some push through to Earth’s stratosphere, which is where the precious ozone layer resides. When this happens, the high-energy particles break apart the lower energy gas molecules such as nitrogen and water vapour. Once freed, these molecules react with the ozone (O3) molecules, effectively depleting the ozone layer. Studies done to explore the specific effect this has on phenomena such as global warming have shown that less than 1% of ozone, most of which is found in the northern hemisphere, is effectively depleted through this process. However, if a super solar flare ever directly hits Earth, the effects on the ozone layer are likely to be much greater.
The other significance of this is that human-caused depletion of ozone occurs over a long time-period; however, ozone depletion due to solar flares produces an immediate change in the atmosphere. So, it is highly probably that if a massive solar flare does occur, it will progress much more towards global-warming than humans have ever managed. According to the National Research Council, increase in radiation to the Earth’s surface due to solar activity, including solar flares, is much greater than increase due to ozone depletion caused by man-made fluorocarbons (the most destructive of greenhouse gases).
The depletion of the ozone layer, as has become increasingly advertised, can prove very destructive for all biological systems on Earth. These effects include but are not limited to the spread of infectious diseases such as malaria, more frequent and stronger hurricanes, increased probability of drought and heat waves which would prove disastrous because all life depends on water, and, perhaps most catastrophic of all, the melting of the ice-caps which would prove disastrous for life sustained throughout the world by throwing the ecosystem off-balance.
Because of the four areas discussed above, all of which are adversely affected by solar flares, it is very important that scientists here on Earth keep close tab on solar flares and keep doing experimental research to determine their effects. The knowledge we currently have about solar flares is usually enough to predict the coming of a flare a few hours before it happens, but not enough to predict exactly the effects it will have on human existence, both on Earth and in space. The knowledge base about solar flares must therefore continually evolve so that humankind can better protect itself against the potential harm they cause.
Also, energy release processes similar to solar flares occur in other cosmic events; but these events are generally too far away to be studied in as much detail as solar flares can be studied from Earth. Therefore, it is essential to study solar flares for the sake of acquiring knowledge about important phenomena that are too far away for direct study.
Historical Examples
Solar flares have been an integral factor in the course of human development. This is most evident during several astronomically significant solar storms which had implications on Earth, even though the Earth is approximately 150 million km from the Sun.
Carrington Event, 1859
The most powerful solar event in recent human history would be the Carrington Event of September 1859. Richard Carrington, an astronomer, observed one of the few white-light solar flares in human history. This same solar flare caused “skies all over planet Earth erupted in red, green, and purple auroras so brilliant that newspapers could be read as easily as in daylight. Indeed, stunning auroras pulsated even at near tropical latitudes over Cuba, the Bahamas, Jamaica, El Salvador, and Hawaii.” This is a testament to the sheer might of the solar flare. Even though this solar flare happened in 1859, when use of technology was way less than it is now, it still had dramatic repercussions for the inhabitants of Earth. For instance, the charged particles from the flare “electrified telegraph lines, shocking technicians and setting their telegraph papers on fire; Northern Lights spread as far south as Cuba and Hawaii; auroras over the Rocky Mountains were so bright, the glow woke campers who began preparing breakfast because they thought it was morning.” A report recently published by NASA indicated that a recurrence of the Carrington Event would cause roughly $2 trillion (20 times greater than the costs of Hurricane Katrina’s damage, or several federal stimulus packages) in damages in the first year. Global telecommunications would be detrimentally affected, and any electrical grids not shut down in time and disconnected would be fried for weeks or even months. Evidently, this would have the potential of being the greatest natural disaster in recorded human history, if combined with civil unrest.
Now, that sounds a bit sensationalist. However, a less powerful solar event did manage to have a severe impact on human technology.
The 1989 Quebec Event
On March 9-10, 1989, solar flares erupted from the surface of the Sun and made their way towards Earth, sending powerful waves of charged particles and radiation. By March 13, the radiation and particles had reached Earth, causing catastrophic failure in the Quebec power grid. The electromagnetic forces generated by the flare overloaded transformers across Quebec, causing the entire grid to destabilize and quickly shut down. This left the entire province without power in a matter of minutes. This solar event clearly illustrates the weaknesses of human technology.
Even though the Earth possesses a magnetic field, it is inadequate to fully protect the Earth from the effects of a solar flare. There are simply too many charged particles and too much radiation for it to be a perfect shield. However, it still manages to block most of the effects of a solar flare. This is why astronauts in space and future colonists must take major precautions against solar activity: there is less protection in low Earth orbit, and much less protection around planets like Mars.
In order to combat this threat, it is important that space weather is monitored and preparations be undertaken when severe solar events are detected by satellites that monitor the Sun. The Earth is at the Sun’s mercy, after all. Although solar flares are not civilization-enders, as depicted in the movie Knowing, they still possess severe implications for people who reside on this great planet.
Conclusion
Human existence is dependent on the Sun, because without sunlight, there would be no photosynthetic primary producers from whom to derive food and no heat with which to keep warm. However, the Sun can also present a danger to humanity precisely because it holds so much energy. Paradoxically, the Sun, which gives us life, can also cause us severe damage.
Solar flares are naturally-occurring phenomena that release huge amounts of energy from the most energetic celestial body of the solar system, the Sun. Usually, solar flares are relatively small and the resulting radiation is not enough to harm humans. However, large class X solar flares release a great amount of the Sun’s energy. The resulting outpour of radiation in the form of solar wind can have many adverse effects on the human system of habitation and communication. It can hamper global telecommunications, can prove destructive for astronauts and space equipment, may have an adverse effect on biological systems on Earth, and actively contributes to the depletion of the ozone layer and the resulting increase in global warming. All of these factors were present in both the Carrington Event of 1859 and the 1989 Quebec Event.
How serious are the implications of a large solar flare? Solar flares are unlikely to be apocalyptic given the current state of the Earth’s atmosphere. The Earth’s powerful magnetic field and ionosphere are aptly able to deflect and absorb most of the radiation that comes along with solar flares. Essentially, the worst that could happen is that a super solar flare (class X20 or higher) hits the Earth, completely destroying all global telecommunications system, permanently damages satellites, and kills astronauts in space through radiation poisoning. While such an event would be difficult for humanity to recover from, it would be a stretch to attribute the apocalypse to a solar flare.
Works Cited
“5 Deadliest Effects of Global Warming.” Environmental Graffiti. 11 Sept 2007. 13 Feb 2010 <http://www.environmentalgraffiti.com/sciencetech/5-deadliest-effects-of-global-warming/276>.
Dmitrieva, I.V. “Experimental confirmations of the bioeffective effect of magnetic storms.” 13 Feb 2010 <http://helios.izmiran.troitsk.ru/helioecology/titles/foll/ bioeffective_confirmations.html>.
Eddy, John A. “Solar History and Human Affairs.” 1994. 13 Feb 2010 <http://www.jstor.org/ stable/4603113>.
“Effects of space radiation on astronauts.” The Medical News. 7 Dec 2007. 13 Feb 2010 <http://www.news-medical.net/news/2007/12/12/33415.aspx>.
Holman, Gordon. 13 Sept 1996. 13 Feb 2010 <http://hesperia.gsfc.nasa.gov/sftheory/index.htm>.
Odenwald, Dr. Sten. “A Conflagration of Storms.” Solar Storms. 1 May 2009. 13 Feb 2010 <http://www.solarstorms.org/SWChapter1.html>.
Phillips, Dr. Tony. “Severe Space Weather.” 21 Jan 2009. NASA. 13 Feb 2010 <http://science.nasa.gov/headlines/y2009/21jan_severespaceweather.htm>.
Ramanujan, Krishna. “A Violent Sun Affects the Earth’s Ozone.” 2 Aug 2001. NASA. 13 Feb 2010 <http://Earthobservatory.nasa.gov/Features/ProtonOzone/>.
YouTube. National Geographic. 13 Feb 2010 <http://www.youtube.com/watch?v=DU4hpsistDk>.
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