• b: Bay-disturbance
  Disturbance within an otherwise undisturbed recording interval of an apparent period of 30 minutes to 2 hours.

• bp: Bay-disturbance connected with pulsations

• bs: Bay-disturbance starting very sharply

• bps: Bay-disturbance starting very sharply connected with pulsations

• si: Sudden impulses
  Sudden displacements of the recorded traces, which cannot be interpreted as ssc because of the lack of a noticeable jump followed by an increase in magnetic activity.

• si*: si, but with at least at one component showing rapid displacement in both directions.

• ssc: Sudden commencements of magnetic storms
  Sudden movement of the recordings within several seconds, often connected with a noticeable jump in one or more components, normally followed by an increase in magnetic activity.

• ssc*: ssc, but with at least at one component showing rapid displacement in both directions.

• sfe: Solar-flare effect
  Wave radiation effect mostly caused by solar eruptions, which occur nearly exclusively in the Earth´s daylight zone. The disturbance-vector has appoximately the same direction as the vector of the normal daily variation. For unambiguous detection, additional data from the National Geophysical Data Center (NGDC) of the US National Oceanic & Atmospheric Administration (NOAA) are used.

For content question please contact:

Jürgen Matzka

Helmholtz Centre Potsdam

GFZ German Research Centre for Geosciences

Public Law Foundation State of Brandenburg

Telegrafenberg, 14473 Potsdam

Germany