Definitions for "magnetic storm"
A sudden disturbance of the earth's magnetic field; caused by emission of particles from the sun.
A descriptive term for the changes in the global magnetic field as a result of the solar wind (in terms of energy, particles, magnetic field and pressure variations). Storms often begin with a sudden enhancement in the horizontal field strength followed over a number of hours by a decline in this field strength before recovery to normal levels over 1-3 days. Storms are often characterised by the behaviour of indices of magnetic activity such as Ap. Magnetic storm activity levels are described as 'Minor', 'Major' or 'Severe' and have specific numerical meanings in terms of Ap. Storms occur under 10% of the time (e.g. 10% of the number of days in a year). 'Quiet-Unsettled' and 'Active' conditions are therefore much more common but are not regarded as important for GIC. Major and Severe storms probably occur no more than 5% of the time in total. Storms and substorms drive ionospheric electrical currents that induce electric fields in the Earth, potentially giving rise to GIC. Back to the top.
A temporary perturbation (disruption) of the Earth's magnetic field, caused by solar flares, which eject plasma from the Sun's chromosphere. This solar plasma travels at speeds of roughly 600 to 1,200 miles per second (1,000 to 2,000 km per second), and after about 21 hours, hit the Earth's atmosphere. Since they disturb the ionosphere (the upper atmosphere), magnetic storms can disrupt radio transmissions.
a spatial phenomenon that posed a navigational hazard in the early days of space travel