Reduced atmospheric ozone results in increased solar ultraviolet radiation (UVR) at the surface which may potentially negative impact public health. We aimed to assess whether or not the break-up of the Antarctic ozone hole had an impact on ozone and UVR at Cape Point (South Africa). We found a moderate inverse relationship between ozone and UVR at midday on clear-sky days. The Antarctic ozone hole had a limited effect on ozone levels while tropical air masses more frequently affected the site.

A localized total electron content enhancement (LTE) was observed as a product of the geomagnetic storm that happened on 8 September 2017. This result was unexpected because it was located south of the equatorial ionization anomaly (EIA). The origin of the enhancement of the TEC in the EIA is very likely due to the super-fountain effect. On the other hand, the LTE is suggested to be produced by the contribution of the super-fountain effect along with traveling ionospheric disturbances.

The magnetopause (MP) is the primary interaction region between solar wind and the magnetic field of planet Earth and understanding of its behaviour also helps to better understand space weather. One famous model of the MP is the Shue et al. model, designed for the dayside and near-Earth situation. We take data of the ARTEMIS mission orbiting the moon and compare the MP position and shape to the model. We find differences in the location prediction but good agreement for the MP normal direction.

We present the dynamics of perturbations during a solar eclipse using rare parameters for eclipse study. Reduction in solar radiation and natural gas heating are the cause of the observed changes. The use of the bottomside F-layer parameters to probe the topside ionosphere established their interrelationship. The implication is that eclipse-caused perturbation could be better explained using some ionosonde parameters.

Occasional deviations in density and magnetic power spectral densities in an intermediate frequency range are interpreted as an ion-inertial-range response to either the Kolmogorov or Iroshnikov–Kraichnan inertial-range turbulent velocity spectrum.

Modelling aurorae, we asked what boundary condition (BC) to use for the E field on the upper boundary. Typically a Dirichlet BC is used, since processes above the domain generate E. But then conductivity structures trigger FACs driven immediately by magnetospheric convection, even though it is a finite energy source, delayed by the Alfvén speed. If the BC is not ideal, then E x B drift in the ionosphere depends on the plasma's properties. So we investigated.

Magnetopause reconnection is a process whereby the Sun explosively transfers energy to the Earth. Whether the process is spatially patchy or spatially continuous and extended has been under long debate. We use space–ground coordination to overcome the limitations of previous studies and reliably interpret spatial extent. Our result strongly indicates that both patchy and extended reconnection is possible and, interestingly, that extended reconnection grows from a localized patch via spreading.

The GPS radio occultation data of the COSMIC-FORMOSAT-3 mission are used to visualize the global distribution of ionospheric irregularities in the F2 region during a geomagnetic storm, at solar minimum, and at solar maximum.

The reflection of solar wind electrons at the bow shock helps define the physical properties of the foreshock, the region where the interplanetary magnetic field directly connects to the bow shock. We report that the strahl, the field-aligned component of the electron solar wind distribution, appears to be nearly fully reflected at the bow shock and that the reflection occurs in the foot of the shock, implying that mirroring is not the primary cause of the electron reflection.