Regional geomagnetic indices are local counterparts of planetary indices of geomagnetic activity. Geomagnetic indices are tools used to monitoring deviations on regular behavior of magnetic field. They are mainly used to identify the effects of space weather on the Earth's environment.

The REGMEX array computes local indices for each operational geomagnetic station (GMS) named K_gms and ΔH_gms. Our GMS are listed on the right side of this page.

REGMEX also computes the Mexican K-index (Kmex) and the regional (Mexican) counterpart of planetary Dst-index (ΔHmex). The near real-timet values of those indices are plot below.

We publish two versions of our indices, the first one is an early (nowcast) version available in near real-time. Few weeks latter, we delivere a final (definitive) version of our indices. You can find our data files in our Products and Data section.

Kmex - Near Real-Time

K indices aims to isolate solar-wind-material effects on the horizontal component of the Earth's magnetic field; over a 3-hour period. These indices classify into disturbance levels, each one relates almost logarithmically to its corresponding disturbance amplitude. Three-hour indices discriminate conservatively between true magnetic field perturbations and the quiet-day variations produced by ionospheric currents.

K index range in 28 steps from 0 (quiet) to 9 (greatly disturbed) with fractional parts expressed in thirds of a unit. A K-value equal to 27, for example, means 2 and 2/3 or 3-; a -value equal to 30 means 3 and 0/3 or 3 exactly; and a K-value equal to 33 means 3 and 1/3 or 3+. The arithmetic mean of the K values scaled at the operative geomagnetic stations of REGMEX array gives Kmex.

Text of Juergen Matzka, adapted from GFZ.

ΔHmex - Near Real-Time

ΔH index is the regional counterpart of the disturbance storm time (Dst) index with out translation to the magnetic Earth's dipole. It is widely use in the context of space weather.

ΔH gives information about the regional magnetic manifestations of temporal intensification of ionospheric currents. These corrents include the ring current, DP2 and Ddyn currents.

Negative values of ΔH imply that regional geomagnetic field is weakened. This is particularly the case during geomagnetic storms. In contrast, positve values of ΔH mean a regional intensification of the magnetic field of the Earth.

Text adapted from Wikipedia.