5. The sun is a typical star, emitting electromagnetic radiation and particles that influence the Earth Sunspots The surface of the sun is shown here in false colours. Sunspots appear yellow, although they would normally appear as dark spots. Sunspots are often larger than 30,000 km and appear in cycles of 11 years. Solar activity, including the development of sunspots, is associated with the sun’s changing magnetic fields. sunspots represent regions of strong magnetic activity and lower temperature When sunspot activity is at a maximum, communication and electricity networks may suffer disruption
Geophysicists believe that convection currents of charged, molten metal circulating in the earth’s core are the source of the magnetic field. 6. The conditions at the surface of the Earth are influenced by the interactions between physical phenomena generated by both the sun and the Earth The internal structure and composition of the Earth produce a magnetic field protecting the Earth from excessive ionising radiation The Earth’s magnetic field traps protons and electrons (in the solar wind) from space in the form of Van Allen belts. These are 2 doughnut-shaped regions that ring the Earth. The charged particles spiral along the magnetic field lines and may enter the Earth’s atmosphere near the poles to cause auroras. The Earth’s magnetic field also deflects dangerous ionising radiation.
In the stratosphere, ozone is formed and creates a layer that protects the Earth's surface from excessive ultraviolet radiation. Outline the composition of the atmosphere and its effect on the penetration of electromagnetic radiation Define black bodies in terms of the heat radiated and absorbed and compare the Earth to a black body The atmosphere traps heat from the sun (infra-red radiation), providing a suitable temperature for survival of organisms. The Earth’s atmosphere consists mostly of Nitrogen (78%) and Oxygen (21%). Other gases include Argon, Carbon Dioxide, Neon, Helium, Methane, Krypton and water vapour. The troposphere is the densest part of the atmosphere and is where we live. ‘space’ begins here These layers may also be referred to as the ‘ionosphere’ and contain many ions and free electrons caused by radiation from the Sun. Gamma rays and X-rays are absorbed by Oxygen and Nitrogen