GK
WORLD GEOGRAPHY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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when the shock wave, associated with the gusty solar wind, compresses the magnetosphere
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when there is a large decrease in field intensity
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when the gust wind itself engulfs the magnetosphere
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None of the above
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Detailed explanation-1: -A geomagnetic storm (commonly referred to as a solar storm) is a temporary disturbance of the Earth’s magnetosphere caused by a solar wind shock wave and/or cloud of magnetic field that interacts with the Earth’s magnetic field.
Detailed explanation-2: -A geomagnetic storm has three phases: initial, main and recovery. The initial phase is characterized by Dst (or its one-minute component SYM-H) increasing by 20 to 50 nT in tens of minutes. The initial phase is also referred to as a storm sudden commencement (SSC).
Detailed explanation-3: -This gust of solar wind disturbs the outer part of the Earth’s magnetic field, which undergoes a complex oscillation. This generates associated electric currents in the near-Earth space environment, which in turn generates additional magnetic field variations–all of which constitute a “magnetic storm."