In order to validate the CSES ionospheric RO data, ionospheric peak values, peak heights and electron density profiles observed by CSES are compared with the corresponding COSMIC RO measurements obtained from February 12, 2018 to March 31, 2019. The results show the two sets are in good agreements, and CSES ionospheric RO data are available for ionospheric related studies considering the extensive validation and application of COSMIC RO data.

The paper discusses a problem concerned with the excitation of chorus with small wave normal angles along the external magnetic field in the magnetosphere. We examine the realization of the beam pulse amplifier mechanism of chorus excitation without strong anisotropy of the plasma particles distribution function in the density ducts with refractive reflection. It is shown that in the ducts, discrete spectral elements of chorus can be excited close to half the electron cyclotron frequency.

The paper shows a statistical analysis of Pc3 and Pc5 pulsations recorded during 60 days (September to November 1994) by a meridional magnetometer profile crossing the dip equator in central South America. This is the first time that a detailed mapping of latitudinal dependence of pulsation amplification at very low latitudes has been performed. One of the most prominent findings is that our equatorial Pc5s might be related to both horizontally and vertically incident MHD waves on the ionosphere

Distributions of proton fluxes in the Earth's Radiation Belts (ERB) are well studied and the NASA empirical models constructed for them. For heavier ERB ions (helium, oxygen, etc.) there are only fragmentary data and no sufficiently complete and reliable empirical models. Using our methods, these data one can streamlined, linked to each other and get a regular picture that has a simple physical meaning.

The morphological characteristics of ionospheric response to tropical cyclone Debbie passing eastern Australia in 2017 is investigated by GPS and ion sounder. The results agree with the previous viewpoint that tropical cyclone can trigger ionospheric disturbance. Considering the influence from the geomagnetic and solar activity, the turbulent top movement theory is utilized to explain how tropical cyclone causes ionospheric irregularity and further triggers ionospheric scintillations.

Atmospheric drag due to mass density distribution, particularly during storm-time, is of great importance for Low Earth Orbit Precise Orbit Determination, and for the understanding of Magnetosphere-Ionosphere-Thermosphere phenomena. In this paper, we investigate solar-cycle, seasonal, and hemispheric asymmetry dependencies of thermospheric mass density disturbances due to magnetospheric forcing, from 10-year (2003–2013) continuous time-series of GRACE estimates.

For the first time, the climatology of intermediate descending layers (~ 150 km) over Brazilian equatorial and low latitudes regions during the extreme solar minimum period of 2009 was investigated. The results are interesting and innovative. For this analysis we used data of height and top frequence of intermidiate layers collected from Digisonde located at São Luis and Cachoreira Paulista.

Winds in the Earth's upper atmosphere cause magnetic and electric variations both at the ground and in space all over the Earth. According to the model of entangled dynamos the true cause is wind differences between regions in the northern and southern hemisphere that are connected by the Earth's dipole-like magnetic field. The power produced in the southern dynamo heats the northern upper atmosphere, and vice versa. The dynamos exist owing to this entanglement, an analogy to quantum mechanics.

The wavelet transform was employed in 9 HILDCAA events for intervals that the Cluster crossed the magnetotail in order to identify the most energetic periods of this events in the magnetotail. It was seen that 76 % of the periods identified are ≤ 4 hours. Using the cross wavelet analysis technique between Bz-IMF component and the Bx geomagnetic component, it was identified that the coupling of energy is stronger in periods between 2 and 4 hours, which are typical substorm periods.

Scaling laws and energy spectra for the electric field, magnetic field, flow velocity, and density are theoretically derived for small-scale turbulence in space plasma on which the electrons behave as a fluid but the ions more as individual particles due to the difference in the mass (the Hall effect). Our spectrum model for small-scale turbulence can qualitatively explain the turbulence spectra measured in near-Earth space.

We have analysed data from radiation monitors on board different spacecraft such as Rosetta and Integral. From the data, we extracted the evolution of galactic cosmic rays as a function of time (over a full solar cycle) and position (from 1 to 4.5 astronomical units). As main results, we confirm the overall evolution (anti-correlation) of the fluxes with respect to the solar activity. We found a surprising result, which is a decrease of the flux of galactic cosmic rays around comet 67P.

Chromospheric flows are of significant importance to understand the mechanisms of transfer of plasma and energy from lower atmosphere of the Sun to the corona through transition region. We study the quiescent loop system in terms of Doppler velocities at the footpoints of individual loop strands to understand the heating mechanisms driving plasma flows in such loop system.

By shooting away electrons from a spacecraft, it will deplete its surrounding electrons and create a large range of positively charged plasma, which will couple with an even larger range of the ambient plasma, and be accelerated or decelerated according to the relative speed between the craft and its ambience. A spacecraft can use the solar wind, artificial particle beam, or cosmic jet to achieve very high interstellar travelling velocity, or brake at the destination, with no propellant.

Solar jets driven from the heating or pressure pulse at the footpoints in the photosphere transfer energy and mass in to the corona. These jets energize the coronal part of the atmosphere with the collimated plasma similar to the fluid filled in a pipe. Understanding the physical drivers of such jets is of great significance to study the plasma in confined magnetic fields. The modelled jets in our paper studies the evolution of chromospheric plasma and support many existing observations.

The paper treats analytically and numerically the new theoretical basis for ground-based and satellite monitoring the most powerful processes in the lower atmosphere/Earth (hurricanes, earthquakes etc.), solar wind-magnetosphere (magnetic storms) and ionosphere (lightning discharges/thunderstorms etc.). This can be provided by determination of phases and amplitudes of radio waves of kHz range in cavity Earth-Ionosphere. In perspective, the damage from the natural disasters can be decreased.

Before the solar wind encounters the Earth's magnetic field, it is first slowed down and deflected by the Earth's bow shock. We find that downstream of the bow shock regions where the shock normal and the solar wind magnetic field are almost parallel and the shock is more rippled, plasma jets with high earthward velocities are observed significantly more often than elsewhere downstream of the shock. Our results help us forecast the occurrence of these jets and their effects on Earth.

In this paper, an extensive study has been done in order to investigate periodic oscillation in the start time of spread-F observed over Brazil. Using OI6300 airglow images and range time integration from a backscatter coherent radar, it was possible to detect semimonthly oscillations in the start time of Equatorial Plasma Bubbles, Plumes and Bottom-type spread-F. The knowledge of this oscillation must be important to understand the dynamics of the day-to-day variability of spread-F.

Winds near the top of the atmosphere are expected to be the same at all heights for a given location. This is due to assuming high viscosity in rarefied gases. However, wind measurements from satellite drag at 350–400 km altitude are found to be up to 2 times larger than optical measurements at ~ 240 km. Satellites provide global measurements, and ground-based optical instruments provide long-term monitoring at single sites. So we must understand this inconsistency for correct physics prediction.

To check the difference between data observed at different altitudes of the Demeter satellite, a statistical method is adopted to evaluate whether data difference is caused by normal data fluctuation or by altitude adjustment. Based on the method, the in situ electron density data at higher altitude are found to be greater than that at lower altitude. We speculate this phenomenon is caused by stratification above F2 peak region. The proposed method is useful when comparing fluctuated data.

Local occurrence rate (LOR) is defined to clarify the characteristics of ionospheric irregularities together with monthly occurrence rate (MOR) at 20–29° N in solar minimum, medium and maximum years of 2008, 2003 and 2014. MOR of irregularities in May/June is larger than that in equinoxes, which is different with the equatorial plasma bubbles. LOR shows that the irregularities at 26–29° N in May/June are more frequently happened and have smaller spatiotemporal scales than those at lower latitudes.

We present the MLT-distribution of energetic particle precipitation into the ionosphere in combination with different substorm activities as well as MLT-dependent trapped plasmaspheric particle flux. MLT dependence can be assigned to different particle sources and energy-specific drifts. The maximum flux asymmetry ratio depends on particle energy, but not necessarily on geomagnetic disturbance. Substorms increase particle precipitation during night (factor 2–4) but may reduce it during day.

When the terrestrial magnetic field is disturbed, particles from the near-Earth space can precipitate into the upper atmosphere. This work presents for the first time numerical simulations of proton precipitation in the energy range associated with the production of aurora (~ 1–30 keV) using a global kinetic model of the near-Earth space: Vlasiator. We find that nightside proton precipitation can be regulated by the transition region between stretched and dipolar geomagnetic field lines.