Dst index

Geomagnetic index Dst (Disturbance storm time) is a measure of the geomagnetic storm intensity. It quantifies the decrease in intensity of the horizontal component of the magnetic field due to the enhancement of the ring current. Dst is an hourly index obtained by merging observations related to four observatories located at magnetic latitudes between +40° and −40°.

Our web pages display 3 types of Dst data depending on the considered period:

- Data from 2013 are real time quick-look values
- Data from 2010 to 2012 are provisional values
- Data from 1957 to 2009 are final values

More information on Dst and on Dst data types can be found at World Data Center for Geomagnetism, Kyoto (http://wdc.kugi.kyoto-u.ac.jp/).