|
August 1972 Solar Storms
The solar storms of August 1972 were a historically powerful series of solar storms with intense to extreme solar flare, solar particle event, and geomagnetic storm components in early August 1972, during solar cycle 20. The storm caused widespread electric- and communication-grid disturbances through large portions of North America as well as satellite disruptions. On 4 August 1972 the storm caused the accidental detonation of numerous U.S. naval mines near Haiphong, North Vietnam. The coronal mass ejection (CME)'s transit time from the Sun to the Earth is the fastest ever recorded. Solar-terrestrial characteristics Sunspot region The most significant detected solar flare activity occurred from 2 to 11 August. Most of the significant solar activity emanated from active sunspot region McMath 11976 (MR 11976; active regions being clusters of sunspot pairs). McMath 11976 was extraordinarily magnetically complex. Its size was large although not exceptionally so. McMath 11976 produ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Active Region
In solar physics and observation, an active region is a temporary feature in the Sun's atmosphere characterized by a strong and complex magnetic field. They are often associated with sunspots and are commonly the source of violent eruptions such as coronal mass ejections and solar flares. The number and location of active regions on the solar disk at any given time is dependent on the solar cycle. Region numbers Newly observed active regions on the solar disk are assigned 4-digit region numbers by the Space Weather Prediction Center (SWPC) on the day following the initial observation. The region number assigned to a particular active region is one added to the previously assigned number. For example, the first observation of active region 8090, or AR8090, was followed by AR8091. According to the SWPC, a number is assigned to a region if it meets at least one of the following criteria: # It contains a sunspot group of class C or larger based on the Modified Zurich Class sunsp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solar Rotation
Solar rotation varies with latitude. The Sun is not a solid body, but is composed of a gaseous plasma. Different latitudes rotate at different periods. The source of this differential rotation is an area of current research in solar astronomy. The rate of surface rotation is observed to be the fastest at the equator (latitude ) and to decrease as latitude increases. The solar rotation period is 25.67 days at the equator and 33.40 days at 75 degrees of latitude. The Carrington a system for tracking the Sun's rotation, as seen from at the current UTC time of , is CR . Surface rotation as an equation The differential rotation rate of the photosphere can be approximated by the equation: :\omega=A+B\,\sin^2(\varphi)+C\,\sin^4(\varphi) where \omega is the angular velocity in degrees per day, \varphi is the solar latitude, A is angular velocity at the equator, and B, C are constants controlling the decrease in velocity with increasing latitude. The values of A, B, and C differ d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
