Sporadic E (Es) layers in the Earth's ionosphere are produced by ion convergence due to vertical wind shear in the presence of a horizontal component of the Earth's magnetic field. We present analyses of the 6 h tidal signatures in ES occurrence rates derived from GPS radio observations. Times of maxima in ES agree well with those of negative wind shear obtained from radar observation. The global distribution of ES amplitudes agrees with wind shear amplitudes from numerical modeling.

The interplanetary magnetic field is a consequence of the solar magnetic field and the solar wind. Different magnetic field models exist in literature that allow us to better understand how the solar field extends throughout the solar system. We highlight different aspects of these different interplanetary magnetic field models and discuss possible applications. Verification of these models will become possible using data from the Parker Solar Probe and BepiColombo space mission.

In this paper, we summarize the anomalous phenomena that were observed before the super-giant earthquake of magnitude 9.0 that occurred on 11 March 2011 in Japan. These phenomena have been detected by means of ground-based measurements and satellite data. We find that all these phenomena are in agreement with a condensed matter physical model that motivated in the 1980s a short-term earthquake prediction method based on the detection of precursory electric signals.

Our research explores a new method for identifying where and when the magnetic field lines in Earth's magnetotail may change its topology through the reconnection process, during which a sudden release of magnetic energy can lead to the brightening of aurora, a process called substorm. Traditionally, the magnetic reconnection was often interpreted using a two-dimensional model, which however does not capture the intrinsically three-dimensional nature of reconnection physics, as we have revealed.

Underground nuclear explosion (UNE) can produce ionospheric disturbances through a lithosphere–atmosphere–ionosphere coupling mechanism, which is very similar with earthquakes. By using the total electron content observations and Swarm ionospheric current data, we have investigated the geomagnetic conjugate ionospheric disturbances. We proposed that the electric field generated during the UNE test can be an important mechanism for ionospheric disturbance.

We investigated the statistical relationship between solar activity and the occurrence rate of major sudden stratospheric warmings (MSSWs). For this purpose, the 10.7 cm radio flux (F10.7) has been used as a proxy for solar activity. The calculations have been performed based on two datasets of central day (NCEP–NCAR-I and combined ERA) for the period from 1958 to 2013. The analysis revealed a positive correlation between MSSW events and solar activity.

Flow channel extending in north–south directions is produced in the initial pulse of Pi2 pulsations associated with the field line dipolarization. Drifts in the ionosphere of the order of kilometers per second accumulated plasmas at the low-latitude end of the flow channel. The plasma compression in the ionosphere produced field-aligned currents, parallel electric fields, and auroral expansion. We called the compressive ionosphere a "dynamic ionosphere".

This paper describes the aerosol measurement setup and results obtained from the BEXUS18 stratospheric balloon within the A5-Unib (Advanced Atmospheric Aerosol Acquisition and Analysis) experiment performed on 10 October 2014 in northern Sweden (Kiruna). The experiment and the results here presented broaden the understanding of the processes linking the presence of charges with particles all over the vertical heights from the ground to the stratosphere.

The fundamental mode of oscillations of the solar atmosphere, f-mode, plays an important role in solar physics. At an early stage of observation, it was found that its frequency is related to the wavelength by a ratio characteristic of waves on the surface of deep water. Subsequent observations revealed its inaccuracy. We derived waves with a different frequency–wavelength ratio and compared them with other possible waves of this type in both the solar and terrestrial atmosphere.

The paper investigates the occurrence of polar mesosphere summer echoes (PMSEs) over a solar cycle. Besides the statistical study of the layered PMSE occurrence ratio, the authors propose a method to deal with the discontinuous EISCAT radar measurements. The method makes it easier to establish a relationship between the layered PMSEs and solar and geomagnetic activities. The paper presents a relatively large data set that brings results. It can be recommended in future research on the PMSEs.

We provide an analysis of processing setting impacts on tropospheric gradients estimated from GNSS observation processing. These tropospheric gradients are related to water vapour distribution in the troposphere and therefore can be helpful in meteorological applications.

To simulate the vertical propagation of atmospheric waves, experimental data on pressure variations at the Earth's surface are used. These data are associated with the meteorological source. The simulation results have allowed for the first time estimates of the amplitudes of temperature wave disturbances in the upper atmosphere caused by waves from the atmospheric front. The simulations have been performed using the Lomonosov supercomputer.