The Adolf-Schmidt-Observatory for Geomagnetism in Niemegk is operated by the GFZ since 1992, continous measurements started in Potsdam already in 1887. Further magnetig observatories are operated in international co-operations from here. The main objective of the observatory is to continuously measure the geomagnetic field, in order to study the dynamics of the Earth´s magnetic field and its interactions with System Earth. Since 1930, the observatory is located 50 km SW of Potsdam.
The Geomagnetic Observatory Wingst (WNG) is operated as a remote station of the Niemegk Geomagnetic Observatory by GFZ since 2004. At the Wingst Observatory, the geomagnetic field intensity and directions have been recorded since 1938 and indices of geomagnetic activity determined since 1944.
The geomagnetic field is a vector field described by intensity and two angles of direction or three other linearly independent components. Shown here are the variations of the components horizontal intensity (H), declination (D) and vertical intensity (Z) around a quiet night time value. They are continuously recorded at the geomagnetic observatory. Horizontal intensity is the component pointing towards magnetic north tangentially to the Earth's surface. Declination is the angle between geographic and magnetic north and vertical intensity is the component perpendicular to the Earth's surface, pointing positive downward.
Variations are given as minute values for the past 24 hours (UTC). They are updated every 10 minutes, if possible.
H and Z are given in Nanotesla (nT), D in minutes (´). The absolute components at Niemegk are obtained by added the usually quiet night time values to the variation values.
The 29-Oct-2003 is showing an extreme geomagnetic storm. Time series graphs of this, the following days or incoming also other storm days are available in an own table.
The values shown here are uncorrected measurement results. Sporadically artificial disturbances (i.e. erroneous values) might occur, which will only be corrected in the final data sets later on.
Shown here is the difference between the variations of horizontal intensity (H), declination (D) and vertical intensity (Z) at the observatories Niemegk and Wingst. Addition of the difference between a moving average values gives the absolute differences.
The average absolute difference is approximatly the difference of field contributions from inside the Earth: the slowly varying main field originating in the Earth's outer core and local, constant field contributions due to magnetized rocks in the Earth's crust (crustal field).
Differences in the variations reflect the inhomogeneity of the field contributions with sources external to Earth in the ionosphere and magnetosphere. During magnetically quiet times the differences vary only slightly as the fields are close to homogeneous over the distance Niemegk - Wingst. During magnetically disturbed conditions the differences can vary with considerable amplitudes. In particular geomagnetic storms show large inhomogeneity.
The differences have different information content in the individual components. Horizontal intensity is most directly influenced by the external field contributions. Variations in vertical intensity are strongly influenced by the electrical conductivity of the subsurface and contain information on the field contributions induced in the Earth by the external variations.
Strong short-period differences in Z between Niemegk and Wingst often are a result from the fact that variations of certain periods have the opposite sign at the two observatories in this component. The different behaviour of horizontal and vertical components can be used to study the conductivity distribution inside the Earth, for example by magnetotellurics.
The values shown here are calculated from uncorrected measurement results. Sporadically artificial disturbances (i.e. erroneous values) might occur, which will only be corrected in the final data sets later on. Such irregular errors may be able to distort the scaling.
The K indices show the local disturbance of the earth's magnetic field. They are displayed for an 81-day period and are updated on workdays. 81 days correspond to three (synodic) rotations of the sun. During strong disturbances, a 27-day repetition tendency is observed.
The K index is a quasi-logarithmic measure of the maximum disturbance in steps of 0 to 9 for three hours (UTC) each; 500nT is the lower limit for K = 9 at Niemegk. Large indices point to a correspondingly higher penetration of corpuscular radiation.
Niemegk and Wingst are among the 13 observatories whose K indices are used to determine the planetary activity index Kp.