RADIO PHYSICS AND RADIO ASTRONOMY

Purpose: Compilation of a digital catalog of magnetic storms in the Odesa magnetic anomaly zone in order to find the reasons for possible changes in the radiation fluxes of cosmic radio sources, according to observations at the URAN-4 radio telescope.

Design/methodology/approach: Since 1987 until now, the radio flux of powerful galactic and extragalactic radio sources has been monitored at the URAN-4 radio telescope of the Odesa Observatory of the Institute of Radio Astronomy of the National Academy of Sciences of Ukraine. The monitoring program includes radio galaxies 3C274, 3C405 and supernova remnants 3C144, 3C461. Changes in the radio source flux level are determined by the ionosphere state due to the changes in space weather. At the “Odesa” geomagnetic observatory of the Institute of Geophysics of the National Academy of Sciences of Ukraine, the geomagnetic field measurements have been made since 1948. Simultaneously, the measurements of three elements of the geomagnetic field: horizontal component (H), vertical component (Z) and inclination (D), have been recorded.

Findings: Using the “Odesa” geomagnetic observatory data, the digital catalog of magnetic storms was compiled for the measuring period of the powerful space radio source fluxes obtained with the URAN-4 radio telescope. For the magnetic storms monitored during the periods of 1987–1995 and 2000–2009, the date and time are shown for the beginning and the end of the magnetic storm, the magnetic storm duration, the amplitude of the three magnetic field elements, being H, Z, and D, and the magnetic storm type characteristic.The “Odesa” geomagnetic observatory is located near the magnetic anomaly zone. To find the distinctions in manifestations of the geomagnetic activity arisen owing to the magnetic anomaly existence, the geomagnetic disturbances recorded at the “Odesa” and “Moscow” (IZMIRAN, Russia) observatories were compared. It was shown that the total annual duration of the magnetic storms was longer in Odesa than in Moscow. This demonstrates some special role of the magnetic anomaly in the development of geomagnetic disturbances.

Conclusions: The digital catalog of magnetic storms in the Odesa magnetic anomaly zone was compiled for the 1987–1995 and 2000–2009 periods. It is also planned to terminate working over the complete catalog of magnetic storms recorded at the “Odesa” observatory for the entire continuous period of monitoring space radio sources at the URAN-4 radio telescope in order to find the manifestations of geomagnetic disturbances impact upon the ionosphere state and changes of intensity in cosmic radio source fluxes. These studies are supplemented by the comparative analysis of the “Odesa” observatory geomagnetic data and the data from some other geomagnetic observatories.

Key words: solar activity; monitoring variability of radio sources; magnetic storms; catalog of magnetic storms; magnetic anomaly

Manuscript submitted 19.10.2020

Radio phys. radio astron. 2020, 25(4): 324-330

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