Variations of the geomagnetic field that accompanied the fall of the Kyiv meteoroid

Heading: 
1Chernogor, LF, 1Shevelev, MB, Tilichenko, NM
1V.N. Karazin Kharkiv National University, Kharkiv, Ukraine
Kinemat. fiz. nebesnyh tel (Online) 2024, 40(3):26-52
Language: Ukrainian
Abstract: 

Theoretical and experimental research of the geomagnetic effect of space bodies remains an urgent task. This is especially true for meter-sized meteoroids, for which the very existence of a magnetic effect remains in question. The purpose of this work is to present the results of the analysis of time variations of the levels of the X-, Y- and Z-components of the geomagnetic field, registered by the INTERMAGNET network of magnetic stations on the day of the fall of the Kyiv meteoroid and on reference days. The analysis of time variations showed that the levels of these components on the day of the explosion of the cosmic body and on the reference days differed significantly. The level of the X-component with a delay time of 6 min decreased by 2...5 nT, which lasted about 60 min. A quasi-periodic disturbance was observed with a delay time of 25 min and a duration of 25 min with a variable period within 4...12 min and an amplitude increasing from 0.3...0.4 to 1.2...1.5 nT. The first disturbance, which had a speed of about 300 m/s, could be caused by an explosive wave. The second perturbation is most likely related to the generation and oblique propagation at hundreds of meters per second of an atmospheric gravity wave. Within the ionosphere, the disturbance propagated at a speed of ~660 km/s with the help of magnetohydrodynamic waves. Temporal variations in the levels of Y- and Z-components on the day of the explosion, fluctuating for ~60 min, decreased by 5...10 nT. The mechanism of long-term disturbances of these components remains unknown. It is likely that it could be related to the diamagnetic effect. There is reason to believe that meter-sized cosmic bodies are able to cause a detectable magnetic effect.

Keywords: aperiodic disturbance, delay time, disturbance duration, generation mechanism, geomagnetic effect, Kyiv meteoroid, propagation speed, quasi-periodic disturbance