Geomagnetic field

secular variation changes at the European magnetic


Orlyuk M.(1),

Sumaruk Yu.(1), Neska A.(2)

(1) Institute of Geophysics National Academy of Sciences

of Ukraine, Kiev, Ukraine, (2) Institute of Geophysics Polish Academy

of Sciences, Warsawa, Poland


The time changes

of the intensity of geomagnetic field and its components at eleventh

magnetic European observatories having long row investigations are

investigated. Secular were calculated as differences between mean year

values of geomagnetic field intensity and its components for 1890

-1920 years. To exclude short period variation, the data rows were

smoothed with running three and eleven year mean values. It is

supposed, that secular variations consist of the two components:

quasi-periodic from internal sources and changeable from external

sources. We suppose that internal sources of secular variations have

long period af changes and this fact may be used to exclude theirs.

The value and sign of the external sources of geomagnetic field

secular variation correlates to values and sign general magnetic field

of the Sun and correspondingly to the values and sign of the mean-year

vertical component of the interplanetary magnetic field. At all

European magnetic observatories the secular variation changes in the

phase but sign of its may differs. Europe is the single region of the

world where positive geomagnetic field secular variations were

observed after about 1920 year. These variations increased in the

pulse regime with period about twenty two years. The maximal values of

positive values of secular variations at European observatories were

observed at middle of thirtieth year of twenty century with exception

of magnetic observatories Coimbra and Tbilisi.