A.Yu. Belinskaya

Manifestation of gravitational tides and planetary waves in long-term variations in geophysical parameters

Long-term variations in the parameters of the Earth’s upper atmosphere and geophysical activity have been studied based on the current spectra. The main sources of quasiperiodic oscillations in the atmosphere (including variations in the solar radiation, geomagnetic activity, and gravity) have been considered. It was shown that the most stable quasiharmonic variations are related to tidal gravitational oscillations and Rossby planetary waves with stable spectra. These oscillatory processes substantially contribute to the dynamics of the middle and upper atmosphere and manifest themselves in ionospheric parameters.

The Chelyabinsk meteoroid: A seismologist’s view

This work determines the parameters of the meteoroid that exploded in Chelyabinsk oblast on February 15, 2013. Using video observation and automobile registration cameras, we identified the trajectory and velocity of the meteoric body from the beginning of its glow to the destruction. The precise explosion time (03:20:34UTC) was determined on the basis of records of the broadband seismic stations and arrivals of the surface wave. The estimated explosion energy with assumption of a point source similar to a high thermonuclear explosion was 100 kt in TNT equivalent based on the surface wave amplitude. The archive of records of seismic stations during the meteorite flight is composed.

Nonlocal electromagnetic response: Implications in the regional sounding

Due regard was given to the nonlocal electromagnetic responses in the processing of the data of the International Baltic Electromagnetic Array Research (BEAR) 1998 Project. Maps of lateral distributions of the apparent electrical resistivity for different time periods were compiled. In these maps, the main tectonic boundaries between the Lapland-Kola, Karelian, and Svecofennian tectonic provinces within the Baltic Shield appear as zones with reduced apparent electrical resistivity. There is supposedly some correlation between the positions of the maxima in electrical resistivity and the maximum Moho depths. In the same way, the data from the network of geomagnetic observatories in the European region (the INTERMAGNET Project) were processed for 2004–2005, and maps of the laterally inhomogeneous distribution of the apparent resistivity in Europe have been compiled for different time periods. The correlation is observed between the positions of the minima in the electrical resistivity and the minima in the thickness of the lithosphere.

Approaches to the estimation of lateral heterogeneity of the upper mantle by electromagnetic methods

The paper addresses the construction of maps showing lateral distributions of the apparent electrical conductivity in various time periods from data of the worldwide network of observatories. The lateral distribution of the apparent conductivity of the Earth is determined by a self-consistent estimation of variations in three components of the geomagnetic field recorded at all stations. The results of processing of data on daily geomagnetic variations observed at the worldwide network in 1964–1968 are presented.

The possible response of the total ozone content on the solar and geomagnetic activity

Abstract The possible total ozone content (TOC) response on the external forcing from solar activity variations, geomagnetic activity variations, and geomagnetic storms was tested on the basis of TOC satellite measurements (NIMBUS-7, TOMS versions 6.0 and 7.0). We tested the existence of 27-day variations in the spectra of TOC variations. The external forcing was investigated for different phases of Quasi-Biennial Oscillations (QBO), which play an important role in Solar-Atmosphere relationships. The results are presented first for East Siberia area and then for different areas well spaced along latitude 52°N.

Morphological analysis of the winter nighttime ionosphere at mid-latitudes of the Asian region

We present a study of peculiarities of the winter nighttime maximum in the critical frequencies f0F2 at mid-latitudes of the Asian region. The data of stations located at different longitudes and close latitudes have been used in the analysis: Novosibirsk (54.8°N, 83.2°E), Irkutsk (52.5°N, 104.0°E), and Khabarovsk (48.5°N, 135.1°E). It has been found that the nighttime maximum in f0F2 is observed after midnight (∼0200–0400 LT) and is a stable feature of the quiet ionosphere from the middle of October to the middle of March at low solar activity (SA) at all analyzed stations. This interval decreases with increasing SA. The difference between the maximal and minimal f0F2 values in nighttime hours is the largest in December–January, and its amplitude is almost independent of SA. Variations in the critical frequency of the hmF2 layer are inversely related to those in the height of the maximum. We have studied periods when the difference between the daytime and nighttime values of f0F2 is less than 2 MHz. The intervals of observations of such events at different longitudes do not coincide. No dependence of the winter nighttime maximum amplitude on magnetic activity has been found.