High-energy electrons in the Earth's magnetosphere can produce operational anomalies in spacecrafts. We investigate the regular variations in these electrons as well as in Pc5 low frequency waves that are capable to generate the electrons. We find that both variables present similar periods in every solar cycle phase. We focus the analysis in the Semiannual Variation of these parameters. The shape of the observational semiannual curves correlate very well with the profiles of the main theories.

Ionospheric irregularities are a common phenomenon in the low latitude ionosphere. In this paper, we compared simultaneous observations of plasma plumes by the JULIA radar, ionogram spread F generated from ionosonde observations installed at the JRO, irregularities observed in situ by Swarm to determine whether Swarm in situ observations can be used as indicators of the presence of plasma plumes and spread F on the ground.

We present a study of ultra-low-frequency waves in the ionosphere and on the ground (geomagnetic pulsations). They can influence particle flux in the magnetosphere, which modify the ionosphere. However, there is no simple dependence between geomagnetic and ionospheric pulsations. We study not only selected pulsations with very high amplitudes but also usual pulsations and try to answer the question, which pulsations' parameters are favorable for modulation of the ionosphere.

Coronal mass ejection sheaths and ejecta are key drivers of significant space weather storms and they cause dramatic changes in radiation belt electron fluxes. Differences in precipitation of high-energy electrons from the belts to the upper atmosphere is thus expected. We investigate here differences in sheath and ejecta induced precipitation using the Finnish riometer chain.

In this work, the correlation between ROTI and S4 is investigated based on a derived mathematical model under the assumption of single screening model for trans-ionospheric signal propagation. The correlation between ROTI and S4 is strongly affected by the variability of the effective velocity, and the correlation coefficient is degraded when the variability increases.The scintillation index S4 depends on the ionospheric irregularities, the effective velocity and the radio propagation path.

Solar atmospheric tides are natural oscillations of 24, 12, 8... hours that contribute to the circulation of the atmosphere from low to high altitudes. Sun heats the atmosphere periodically because, mainly, water vapor and ozone absorb solar radiation between ground and 50 km height during the day. Tides propagate upward and they can be observed in, e.g., wind field. This work presents diurnal tides observed by meteor radar which measure wind between 80 and 100 km height.

Powerful radio waves transmitted into the ionosphere give the strongest turbulence effects in geomagnetic zenith, antiparallel to the magnetic field in the northern hemisphere. Our results obtained with the EISCAT (European Incoherent SCATter association) Heating facility in Norway and the EISCAT UHF incoherent scatter radar together with modeling suggest that the pump wave propagates in the L mode, rather than in the O mode that is usually assumed to be involved in such experiments.

This study treats on the influence of the 2015 Calbuco eruption (41.2° S, 72.4° W; Chile) on the total columnar aerosols optical properties over the Southern Hemisphere. The well-known technic of sunphotometry was applied for investigation of the transport and the spatio-temporal evolution of the optical properties of the volcanic plume. The CIMEL sunphotometer measurements performed over 6 South American and 3 African sites were statistically analyzed.

Spatial-energy distributions of the stationary fluxes of protons, helium ions and ions of carbon-nitrogen-oxygen (CNO) group in the Earth's radiation belts (ERB) are considered here by the data of the satellites for 1961–2017. It is find that the results of these measurements line up by some regular patterns. Solar-cyclic (11-year) variations in the distributions of protons, helium ions and CNO group ions fluxes in the ERB are studied.

Currents are believed to exist in mirror mode structures and to be self-consistent with the magnetic field depression. Bipolar currents are found in two ion-scale magnetic dips. The bipolar current in a small-size magnetic dip is mainly contributed by electron velocities, which is mainly formed by the magnetic gradient-curvature drift. For another large-size magnetic dip, the bipolar current is mainly caused by an ion bipolar velocity, which can be explained by the ion diamagnetic drift.

We present a comprehensive statistical study of the response of the Earth’s space environment during sheath regions preceding interplanetary coronal mass ejections. Inner magnetospheric wave activity is enhanced during sheath regions, and sheaths cause significant changes in the outer radiation belt electron fluxes on short time scales. We show that also non-geoeffective sheaths can result in a significant response.

The near-Earth environment can be divided into three main regions: the magnetosphere, the magnetosheath and the solar wind. The boundaries between the three regions being called the magnetopause and the bow shock. The manual detection of these boundaries in the data of spacecraft orbiting the Earth is ambiguous and time consuming. We elaborated an automatic detection method of the two bondaries. Which provides a considerable gain of time in the analysis of spacraft in-situ data.

This is an extensive model study to analyze the migrating quarterdiurnal solar tide (QDT) and their forcing mechanisms in the middle atmosphere. We show first a climatology of the QDT amplitudes and examine the contribution of the different forcing mechanisms, like direct solar, nonlinear and gravity wave forcing, on the QDT amplitude. Furthermore, we investigate destructive interference between the individual forcing mechanisms.

The Earth's atmosphere is constantly losing molecules and charged particles, amongst them oxygen ions or O⁺. Quantifying this loss provides information about the evolution of the atmosphere on geological timescales. In this study, we investigate the final destination of O⁺ observed with Cluster satellites in a high-altitude magnetospheric region (plasma mantle) by tracing the particles forward in time using simulations. We find that approximately 96 % of O⁺ escape the Earth's magnetosphere.