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Coronal Mass Ejections
A Coronal Mass Ejection (CME) is a great bubble of
gas, threaded with magnetic field lines that release
large quantities of matter and electromagnetic
radiation into space.
A CME is an ejection of the corona of the Sun. Each
CME consists of a plasma primarily made up of
electron and protons.
Solar Flares
A sudden eruption of magnetic energy released on or
near the surface of the sun, usually associated with
sunspots and accompanied by bursts of
electromagnetic radiation.
Solar flares may last between several hours and several
days, and have temperatures ranging from 20 to 100
million degrees Kelvin
In this part of the presentation
• You will consolidate your understanding of what CMEs and Solar flares are.
• You will see the most accepted cause of CMEs and/or flares
• You will then see data collected both recently and over the previous years that show CMEs occurances’ and the strength of the x-ray flux for these moments in time ( a high x-ray flux means there has been a solar flare).
• I will present our interpretations of the data.
CMEs + flares: common trigger
• I believe that CMEs and flares are produced by a common trigger in the corona.
Corona disruption
Causes Either/both
Solar flare
Coronal mass ejection
CMEs + flares: common trigger
• We believe that CMEs and flares are produced by a common trigger in the corona.
Causes Either/both
Solar flare
Coronal mass ejection
Causes Either/both
Solar flare
Coronal mass ejection
Corona disruption
Causes Either/both
Solar flare
Coronal mass ejection
CMEs and Flares: Common trigger
• Recent scientific research suggests that the phenomenon of magnetic reconnection is responsible for CME and solar flares. Magnetic reconnection is the name given to the rearrangement of magnetic field lines when two oppositely directed magnetic fields are brought together on the corona.
• The sun is constantly rearranging its magnetic fields in its corona as part of its 22 year cycle. During which it goes through a period of Solar maximum and Solar minimum.
• To explain this; imagine the sun as a bar magnet.
6-day CME and flare data (1st set)
• It shows the x-ray flux over time which is used to identify flares; and it also shows when CMEs occurred.
• We can identify the x-ray flux at the moment of a CME emission.
28th June
20:48 X-ray flux
Observed CME
29th June
02:24 X-ray flux
Observed CME
1st June
19:59 X-ray flux
Observed CME
3rd July
2:48 X-ray flux
Observed CME
4th July
03:24 X-ray flux
Observed CME
5th July
04:22 X-ray flux
Analysis of Results
• Out of the 6 CME emissions observed from 28th – 5th July, none of them corresponded to a related flare emission. All of these CME’s observed were small compared to possible sizes of CMEs.
• We draw this conclusion: Based upon the results of the 6 day period I predict that weak CMEs don’t coincide with a flare.
Large CME ejections: 2ND Set
June 7 2011
09:19 X-ray flux
Observed super CME
4th November 2003
20:06 x-ray flux
Observed super CME
Super CMEs
• From these two super CMEs they both suggest a correlation between CMEs and flares; contrary to the 1st set of data
• The only difference between the 2nd set of CMEs and the 1st set is that they occurred on a larger magnitude.
• …So does the size of a CME determine whether it has a corresponding flare?
Model: • Lets imagine the sun was a balloon filled with
water and air to try and understand why large CMEs seem to have flares but small CMEs don’t.
Balloon = sun Hole = gap in sun’s magnetic field Air = CME Water = Flare
Coronal mass
ejection through gap
in magnetic field.
The magnetic field can
recover over the small gap and there has been
only a small amount of
emission
Small hole Easily fixed
CME only
Massive Coronal
Mass Ejection
through hole in magnetic field
Flare can escape too
through the gap
Massive CME
Solar flare too
Large hole
To conclude this part of the project To conclude this part of the project
1.) Solar flares and CMEs are caused by magnetic reconnection on the corona; and they can but don’t have to occur with one another.
2.)The larger the disturbance in the magnetic field; the larger the CME/flare that will be emitted.
3.) Also; for large CMEs and flares they are more likely to have a corresponding flare/CME.
Geomagnetic storms
http://www.russia-ic.com/education_science/science/breakthrough/1097/
http://www.physics.adelaide.edu.au/wiser/scientific.html
• A geomagnetic storm is a transient disturbance of the Earth's magnetosphere.
• The disturbances in the geomagnetic fields are caused by fluctuations in the solar wind impinging on the Earth.
http://en.wikipedia.org/wiki/Geomagnetic_storm
Geomagnetically Induced Current
http://en.wikipedia.org/wiki/Geomagnetically_induced_current
Flowchart of events
CME ejects charged particles
Charged particles flow into the ionosphere creating electrical currents
Electrical currents in the atmosphere create varying magnetic fields
Varying magnetic fields induce electrical currents in the ground, power lines, and pipelines
Causes of geomagnetic storms
Coronal mass ejection (CME) driven
Co-rotating interacting regions (CIR) driven
Solar flares
Effects of CMEs on Earth
Auroras are formed when matter ejected from the corona releases photons in the atmosphere. These are also known as the Aurora Borealis in the northern hemisphere and Aurora Australis in the southern hemisphere
Coronal Mass Ejections, along with solar flares affect the ionosphere. This means that it becomes less efficient at reflecting radio waves back to the earth’s surface. This can contribute to a disruption radio transmissions and signals, meaning a disruption in radio communication over the planet.
Astronauts, who are less protected by the earth’s magnetic field, are more likely to be subjected to exposure to radiation which could be dangerous/ fatal. As well as this equipment on space shuttles could be damaged, making missions into the further reaches of space difficult, and potentially extremely costly in order to give protection to equipment and crew.
People travelling at high altitudes in the earth’s atmosphere, e.g. people travelling to Australia via plane, risk exposure to intense radiation (2-3 mSv of X-rays) as they are less protected from the earth’s atmosphere, especially to more penetrative radiation.
The high energy particles released by CMEs can cause damage to satellites orbiting the planet, which are less protected by the earth’s magnetic field and atmosphere, destroying circuits and making them unusable. Replacing and repairing satellites is extremely time consuming, taking years to design and then build new satellites, and are also very costly, costing millions of dollars to build or repair.
The upper atmosphere can also become charged to due interaction
with CMEs. This can affect national power grids, as wires can pass a current from the charged particles in the atmosphere, potentially causing huge and long-lasting power shortages, such as in Quebec 1989.
In March 1989 there was a severe geomagnetic storm that caused the collapse of Québec's electricity transmission system.
• Result of a coronal mass ejection on March 9
• March 13, 1989, a severe geomagnetic storm struck Earth.
• Widespread Damage and confusion
Effect of a Solar Flare on the Earth
• Solar flares are dangerous to living organisms.
• However, surface of the Earth is protected by the Earth's magnetic field and atmosphere.
• The energetic particles seldom reach the Earth
• They do disturb the Earth's ionosphere, which in turn disturbs some radio communications.
• Causes the atmosphere to expand and increases drag on space junk and satellites
• Biggest change during Solar maximums
Conclusion
Our task was to discover whether or not there was a correlation between the
occurrence of Coronal Mass Ejections and Solar Flares, and the effects on
Earth.
Over the course of our project we have come to the final conclusion that there
is no directly causal relationship between them.
It appears to that for event of a Flare coinciding with an Ejection, the Coronal
Mass Ejection must be of a large enough magnitude
We believe that the true nature of the relationship would be better understood if
more a sample of a greater size was used.
CME’s have more effect on Earth than Solar flares do.
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