Geo-Magnetic Indices

}As we know our Earth is protected by these solar activities by its own magnetic filed shield. Which guards our planet from activities like solar winds and storms. Magnetic field is the first , where these solar activities gets into contact with our Earth’s atmosphere. Thus a deep understanding of the governing laws of these magnetic fields of Earth and impact on it by solar activities is required.

Below are the definitions and Real-Time Monitoring of Various Geo-magnetic Indices:-

ØDisturbance Strom Time : The Dst index monitors the variations of the globally symmetrical ring current, which encircles the Earth close to the magnetic equator in the Van Allen (or radiation) belt of the magnetosphere. The Dst is a geomagnetic index which monitors the world wide magnetic storm level. It is constructed by averaging the horizontal component of the geomagnetic field from mid-latitude and equatorial magnetograms from all over the world.

http://wdc.kugi.kyoto-u.ac.jp/dst_realtime/presentmonth/index.html

ØAuroral Electrojet : These indices describe the disturbance level recorded by auroral zone magnetometers. Horizontal magnetic component recordings from a set of global stations are plotted to the same time and amplitude scales relative to their quiet-time levels and then graphically superposed. The upper and lower envelopes of this superposition define the AU (amplitude upper) and the AL (amplitude lower) indices, respectively. The difference between the two envelopes determines the AE (Auroral Electrojet) index, i.e., AE = AU - AL. AO is defined as the average value of AU and AL.

http://wdc.kugi.kyoto-u.ac.jp/ae_realtime/presentmonth/index.html

}Magnetic A-Index-The geomagnetic A-Index represents the severity of magnetic fluctuations occurring at local magnetic observatories. During magnetic storms, the A-index may reach levels as high as 100. During severe storms, the A-index may exceed 200. Great "rogue" storms may succeed in producing index values in excess of 300, although storms associated with indices this high are very rare indeed.

http://www.swpc.noaa.gov/alerts/a-index.html

}Magnetic K-Index- The geomagnetic K-Index is related to the A-index. K-indices are scaled by comparing the H and D magnetometer traces (representing the horizontal and declination magnetic components) to assumed "quiet-day curves" for H and D. Each UT day is divided into 8 three-hour intervals, starting at 0000 UT. The planetary 3-hour-range Index Kp is the mean standardized K-index from 14 geomagnetic observatories between 44 degrees and 60 degrees northern or southern geomagnetic latitude. 

http://www.swpc.noaa.gov/alerts/k-index.html

Daily solar-Indices:

http://www.swpc.noaa.gov/alerts/solar_indices.html