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Geomagnetic field secular variation changes at the European magnetic observatories |
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Orlyuk M.(1), Sumaruk Yu.(1), Neska A.(2) |
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(1) Institute of Geophysics National Academy of Sciences of Ukraine, Kiev, Ukraine, (2) Institute of Geophysics Polish Academy of Sciences, Warsawa, Poland |
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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. |
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Observatories |
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oral |
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