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Aurora: Curtains of light glowing in the upper atmosphere. Auroras are the result of charged particles from CME interacting with earths Magnetic Field. These are basically two types; Aurora Australis commonly known as Southern Lights and Aurora Borealis known as Northern Lights and
Corona:Â Outer layer of the Sun's atmosphere. Extremely high temperature and is composed of superheated, highly diffused and ionized gases. It extends into interplanetary space. Some of these hot gasses escape the Sun forming solar wind.
Coronal Mass Ejection (CME): High speed CMEs produce major disturbances in the solar wind. They often appear like loops and emerge as a massive cloud of material from solar atmosphere. These disturbances produce dangerously high energy charged particles. These particles when directed towards Earth result in large magnetic storms in the Earth's magnetosphere.
Electromagnetic Spectrum:Â spectrum or range of various kinds of wavelengths of electro-magnetic radiation or light. This includes (from short wavelengths to long): Gamma Rays, X-Rays, Ultraviolet, Visible, Infrared and Radio.
Geosynchronous:Â Refers to an orbit around the Earth's Surface which is almost equal to the diameter of earth from the center of Earth (Radius of Earth being about 22,300 miles). Its Period of rotation is equal to one day. An object in this Orbit will always stay at the same point from Earth's Perspective. Hence Communication Satellites are mostly launched to circle the Earth in this Orbit. This is So that receivers on Earth are always pointed to transmitters on these satellites
Heliosphere:Â It is a humongous magnetic bubble that contains the entire solar magnetic field and the solar wind. The interstellar medium consists of plasma that fills our Milky Way. It meets the Solar Wind at the outermost boundary of Heliosphere. The boundary is estimated to be further than the orbits of all planets i.e. between 9 and 15 billion kms away from the Sun.
Ionosphere: The Earth's atmosphere extending from around 50 to 300 miles above Earth's surface. This layer is dominated by ionized i.e. electrically charged, atoms.Â
Magnetic Storms and Substorms:Â it is a series of disturbances resulting from high speed Solar wind and rapid fluctuations in Earth's magnetic field. Magnetic storms cause failures in Power Grid and Blackouts in Radio Communication. These are less frequent in occurrence as compared to Magnetic substorms. Magnetic substorms are also called auroral substorms.
Magnetosphere:Â It is a region formed when the solar wind stretches Earth's magnetic field. The magnetosphere works with Earth's atmosphere to protect us from the direct effects of solar wind and other radiation.
Plasma:Â It is one of the four states in which matter exists. (The other three being solid, liquid and gas.) It is a very hot gas that is conducive to flow of electricity. It also responds to magnetic and electric forces. Although Plasma is rarely found on earth it is what the Sun constitutes of and what outer space is made of. Plasma consists of almost equal concentrations of negatively and positively charged particles, which makes the entire gas in outer space as neutral.
Solar Wind:Â It is a continuous stream of charged particles pouring out from the Sun. This Solar wind is main reason for Auroras when it interacts with Earth's magnetic field. The solar wind comes out of the Sun at a million miles per hour and 200 tons per second.
Space Weather:Â The various phenomenon in Space that effect the Earth's environment are termed as Space Weather. These phenomenon include changes in the magnetic field of Interplanetary Space, CMEs from the Sun, and disturbances in magnetic field of Earth. The effects of space weather can range between less drastic effects like Auroras on Poles to more long lasting effects like interference of power grids on Earth to damage to satellites.
Sunspot:Â An area which is filled with abundance Sun's Magnetic Field. This area usually appears as dark spot on the Sun's surface since its cooler than surrounding plasma. Sunspots look are cooler and hence darker than the surrounding plasma. Life of sunspots varying between several hours to months. They appear in groups and the number of sunspots within group increase and decrease over eleven-year cycle. This Cycle is commonly known as solar cycle. Area of some sunspots is as big as 20 times the Earth's diameter.
DYNAMAC: Dynamics Algorithm based Compression
SOHO: Solar and Heliospheric Observatory
NASA: National Aeronautics & Space Administration
IEEE: Institute of Electrical and Electronic Engineers
SPE: Solar Proton Event
CME: Coronal Mass Ejection
2-D: Two dimensional
3-D: Three dimensional
NGN: Next Generation Networks
FSWC: Fourier Series Waveforms Classification
CCO: Chaotic Oscillation
GUI: Graphic User Interface
Several National and Academic organizations have been engaged in finding a day to day solution to predict Solar Activity. However, we still need to find a better solution to accurately predict Solar Activity. For instance, the Carrington Flare of September 1859 brought down the Telegraph service as it is dependent on batteries at that time and also Quebec Blackout of 1989 caused power failure for more than 9 hours. This infers that our Space Weather Prediction system is still primitive. Since 1995, geomagnetic storms andÂ solar flaresÂ have been monitored from theÂ Solar and Heliospheric ObservatoryÂ (SOHO) satellite, a joint project of NASAÂ and theÂ European Space Agency.
In this paper, we implemented a digital image compression tool, DYNAMAC Algorithm to scan SOHO Sun images obtained from SOHO Satellite; DYNAMAC has its origins in Dynamic Nonlinear Systems, known widely and precisely as chaotic oscillations. This algorithm has been implemented through scanning and processing several Sun images from SOHO, with and without flares. Hence, the average profile of calm Sun is analyzed from various image sample profiles. This average profile is taken as benchmark to detect Solar Activity; as the stored average profile is being used to compare and detect flares from the rest of images. This tool is cost effective as well as easily updated and manipulated.
This project work consists of eight sections: Section one is the introductory chapter which summarizes the Space Weather related to Sun and steps taken for its Prediction. The major cause of concern among everyone who is aware of Carrington Flare and Quebec Blackout and several other such events, is how to predict and be prepared for any after effects of Solar Activity on earth.
Section two discusses the Sun, its Cross-Sectional View and what it is made of. This section also walks the reader through various layers of Sun. While discussing these layers, the paper will touch upon methods the sun uses to create and transmit energy. Solar Atmosphere has also been discussed here to understand the complexity of Sun and its dynamics.
Section three details the background information of Solar Activity; Solar Flare, Solar Proton Event (SPE) and Coronal Mass Ejections (CMEs). The factors causing the flares and its basic composition are one of the main focuses. The stages the flare goes through for one eruption, the strength of flares and their classification based on the energy released during an eruption have been detailed. The subject of the types of flares, depending on their shape and size has been touched upon.
Section four will touch upon the known and predicted effects of Solar activity to understand the need for a system to predict Solar Weather. Though Sun is very far away, the energy it releases is tremendous and will affect the life on earth. In this section we discuss the beautiful effects of Solar Weather i.e. Aurora Borealis and some of its disastrous effects on human health and manmade leisure life.
Section five of this work gives the brief summary of this project work; image compression using DYNAMAC Algorithm to further profile the nature of images to generate a general idea of basic average profile of Sun and how we are getting the flare info from the image samples. This section also touches upon the previous studies done in the area of Solar Flares and CMEs using digital image processing techniques.
Section six is the core part of this paper; this part discusses the DYNAMAC Algorithm. This algorithm has been previously studied on Medical images, like cancer images. The Algorithm was used to generate average Profile of both lung and Breast Cancer, which was then used to study various images to determine whether the tissue was infected or not. Similarly, the average Calm Sun profile was generated by using D transform. The stored average Calm Sun profile has been used to compare new set of Sun images to detect CMEs and Solar Flares by pointing out similarities and differences.
Section Seven analyses results to emphasize on the effectiveness of the DYNAMAC algorithm, when applied to Sun images. It interprets the similarities and differences found between newly scanned and processed images and the derived profile.
2. Background information
An overview and general information about the Sun, its layers and its composition is given in this section. The Processes in the Sun and its complexity has been touched upon briefly. Sun's complex magnetic field has also been looked into and explained for the reader to understand the paper. Finally sunspots, flares and prominences have been introduced on a closing note in this section
2.1 Generic Sun and its Cross-Sectional View
Cross-section of the Sun (SOB)
Figure : Cross-Section of Sun
Sun, as we know it, is a major source of power and energy that keeps life going on earth. The Sun is a typical main sequence star of spectral class G and luminosity Class V, known to man. Various Nuclear and Thermonuclear reactions, which are harmful when triggered on earth, are the major source of energy production on Sun. This energy travels to earth in the form of light and heat to sustain life on earth.
Without Sun, earth might not survive even one season, as natural resources will disappear very quickly, since nature that feeds these natural resources will cease to exist.
2.2 Composition and Layers of Sun
File:Sun parts big.jpg
Figure : Layers in Sun (http://imagine.gsfc.nasa.gov/docs/science/know_l2/sun_parts.html)
The cross-sectional view of a sun has 4 major zones: Core, Radiative Zone, Convective Zone and Photosphere. Above the Photosphere resides the Solar Atmosphere, which constitutes of five principal zones: theÂ temperature minimum, theÂ chromosphere, theÂ transition region, theÂ corona, and theÂ Heliosphere.
The core is the first and inner most zone, which extends from the center to about 20-25% of the solar radius. This zone has 150 times the density of water and has a temperature of around 15.7 million Kelvin. Most of this energy on Sun is produced by Proton-Proton fusion, which creates Helium from Hydrogen atoms. Most of the heat generating nuclear reaction takes place in the core.
2.2.2 Radiative Zone
Very small portion of these nuclear reactions take place in Radiative Zone, which is the 2nd zone after the core. Core, which is made of solar materials, is dense and hot enough that thermal radiation is adequate to transfer the extreme heat and temperature of the core outward. Radiative zone is free of thermalÂ convection; while the material gets cooler from 7 to about 2 million Kelvin with increasing altitude, thisÂ temperature gradientÂ is less than the value of theÂ adiabatic lapse rateÂ and hence cannot facilitate convection. Here, energy is transferred by radiation. Photons are emitted by Hydrogen and Helium Ions. These photons travel only a small distance after which they are reabsorbed by other ions.Â The density of this zone is 100th of density of core (0.2 gms/cm3).
2.2.3 Convective Zone
The Radiative Zone is covered by the third zone, i.e. Convective zone. This zone is 70% away from the center of the core and extends till the Sun's outer layer. Radiation cannot pass the inner thermal energy outward, since the plasma is neither dense enough nor hot enough for radiation. But this same plasma, which does not allow radiation, is conducive enough for Thermal Convection which carries hot materials to the surface of the Sun. As the material reaches the surface, it cools down and again plunges back towards the radiative zone to receive more heat. The density and heat drops to 5,700 K and 0.2 g/m3 respectively at the outer sphere.
The last and the visible zone of Sun is named as Photosphere. This is where the visible sunlight is free to propagate towards the Solar System. The opaque Convective zone changes to visible photosphere zone, because of the decrease in presence of Hydrogen anions (Negative Hydrogen Ions). More clearly, the visible light is produced when electrons react withÂ hydrogenÂ atoms to produce Hydrogen anions. This zone has a temperature of around 6000K and particle density of approximately 1023Â mâˆ’3Â (this is approximately 0.37% of the number of particles per volume ofÂ Earth's atmosphereÂ at sea level. However, since particles in photosphere are electrons and protons, hence the average particle on Earth is 58 times heavier).
2.2.5 Solar Atmosphere
The above four zones comprise of Sun, there are other zones which extend outward from Sun, towards the Solar System, known as Solar Atmosphere. These zones span across the spectrum, from radio to visible to Gamma rays. This Solar Atmosphere comprises of five principal zones: theÂ temperature minimum, theÂ chromosphere, theÂ transition region, theÂ corona, and theÂ heliosphere. This is the region where we see flares from Sun and CMEs which may adversely affect life on earth. Though they are visible in Solar Atmosphere, but they start from the Magnetic Field.
2.2.6 Magnetic Field
The Sun being a magnetically active star supports a strong, changingÂ magnetic fieldÂ that varies year-to-year. It reverses direction about every 11 years around solar maximum.Â Solar Activity is the term coined to represent the effects of these magnetic fields, includingÂ sunspotsÂ on the surface of the Sun,Â solar flares, and variations inÂ solar windÂ that carry material through the Solar System.Â Effects of solar activity on Earth includeÂ aurorasÂ at moderate to high latitudes, and disruptions in radio communications andÂ electric power. This Solar activity is believed to have a large role in theÂ formation and evolution of the Solar System like changing the structure of Earth'sÂ outer atmosphere.
Figure : Magnetic field lines on the Sun, on August 20, 2010. Credit: NASA SDO/Lockheed Martin Space Systems Company
Because of the high temperature, all matter in the Sun is gas and plasma. Due to this, it is possible for sun to rotate faster at equator (~25 days) than at poles (~35 days). The above said difference causes the magnetic fieldÂ lines to twist over time. This in turn causesÂ magnetic field loopsÂ to erupt from the Sun's surface triggering the formation of solar prominences and sunspots. This twisting action creates theÂ solar dynamoÂ and a 11-yearÂ solar cycleÂ of magnetic activity. The Solar cycle of magnetic activity is due to the fact that the Sun's magnetic field reversing itself.
Figure : Solar Cycle over the last 30 years