Earth magnet11/9/2022 ![]() ![]() ![]() The Earth's magnetic field can be closely approximated by the field of a magnetic dipole positioned near the centre of the Earth. Magnetic dip pole can migrate rapidly, observation of up to 40 km per year have been made for the North Magnetic Pole. ![]() The two poles wander independently of each other and are not at directly opposite positions on the globe. At a magnetic pole, a compass held in the horizontal plane points randomly, while otherwise it points nearly to the North Magnetic Pole or away from the South Magnetic Pole, though local deviations exist. Another way of saying this is that the inclination of the Earth's field is 90° at the North Magnetic Pole and -90° at the South Magnetic Pole. Often, a magnetic (dip) pole is viewed as a point on the Earth's surface where the magnetic field is entirely vertical. The positions of the magnetic poles can be defined in at least two ways. ![]() Magnetic declination from true north in 1700 Variations in the magnetic field strength have been correlated to rainfall variation within the tropics. The mechanism of atmospheric stripping is caused by gas being caught in bubbles of magnetic field, which are ripped off by solar winds. These phenomena are collectively called space weather. For example, the levels of ionizing radiation and radio interference can vary by factors of hundreds to thousands and the shape and location of the magnetopause and bow shock wave upstream of it can change by several Earth radii, exposing geosynchronous satellites to the direct solar wind. The solar wind is responsible for the overall shape of Earth's magnetosphere, and fluctuations in its speed, density, direction, and entrained magnetic field strongly affect Earth's local space environment. Geomagnetic storms result when the pressure of plasmas contained inside the magnetosphere is sufficiently large to inflate and thereby distort the geomagnetic field. Bright auroras strongly heat the ionosphere, causing its plasma to expand into the magnetosphere, increasing the size of the plasma geosphere, and causing escape of atmospheric matter into the solar wind. The only time the solar wind is observable on the Earth is when it is strong enough to produce phenomena such as the aurora and geomagnetic storms. A smaller number of particles from the solar wind manage to travel, as though on an electromagnetic energy transmission line, to the Earth's upper atmosphere and ionosphere in the auroral zones. Some of the charged particles from the solar wind are trapped in the Van Allen radiation belt. Regular grades of neodymium have lower maximum operating temperatures than samarium cobalt magnets and are susceptible to corrosion if not coated.Simulation of the interaction between Earth's magnetic field and the interplanetary magnetic field.Įarth is largely protected from the solar wind, a stream of energetic charged particles emanating from the Sun, by its magnetic field, which deflects most of the charged particles. Neodymium magnets are made from an alloy that mainly consists of neodymium, iron and boron and, depending on the grade of magnet being produced, varying amounts of dysprosium and praseodymium. When neodymium magnets were discovered in 1982 by General Motors and Sumitomo Special Metals they took the title of the strongest permanent magnets available, which they retain to this day. Until the introduction of neodymium magnets they were the strongest magnets available, they are extremely difficult to demagnetise, have high maximum operating temperatures and have a high resistance to corrosion. Strnat and are made from an alloy of samarium, cobalt, iron, copper, hafnium, zirconium and praseodymium. Samarium cobalt magnets were the first to be discovered in 1966 by Dr. There are many different grades of each, all of which have different properties. There are two types of rare earth magnet, neodymium magnets (NdFeb) and samarium cobalt (SmCo) magnets. ![]()
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