Recent  

Our research investigates how different proxies of solar activity influence long-term trends in the Earth's ionosphere. By analyzing data from two mid-latitude stations up to 2022, we found that the choice of solar activity measures significantly affects trends in ionospheric electron density, while trends in ionospheric height remain more stable. Selecting the correct solar activity measure is crucial for accurate density trend predictions and improving space weather forecasting models. ​

The study analyzes hourly NmF2 data from Juliusruh (1957 to 2023) and examines the response of NmF2 to solar flux by using three different solar EUV proxies for six solar cycles, including a separation of the ascending and descending phases. The response is better represented with a quadratic regression and F30 shows the highest correlation for describing NmF2 dependence over time. These results revealed a steady decrease in NmF2, influenced by the intensity of the solar activity index.

There is limited discussion on the impact of SSR corrections based on different ACs on RT ZTD accuracy. In this study, RT-PPP based on multiple ACs is used to estimate the positioning performance and ZTD accuracy of SSR products based on different ACs. GNSS from 8 IGMAS stations is increased from 355 in 2023 to 14 in 2024. WHU-SSR has a higher accuracy of RT-PPP derived ZTD with an RMSE of 6.06 mm and a perfect availability with an integrity rate of 89 %.

Ground-based magnetometer observations show that part of the near-Earth cross-tail current closed itself via the ionosphere, to which it was linked by the substorm current wedge, and manifested itself in the magnetograms acquired at high and equatorial latitude stations on the night side of the Earth. Observations suggest that the B_z interplanetary magnetic field component threshold for the formation of the substorm current wedge lies in the –(22–30) nT interval.

The lack of ground observation instruments and the vast ocean coverage make the Southwest Indian Ocean (SWIO) region difficult to access and poorly studied. For gathering ground-based camera information, satellite measurements have been used with the primary goal of characterizing both sites Saint-Denis of Reunion Island and Antananarivo Madagascar in terms of cloudiness. This study shows the particularity of each site and enhances our understanding of cloud properties, particularly in the SWIO.

Our study probes how solar wind disturbances affect cosmic rays at Earth during solar eruptions. Increased cosmic rays during heightened solar wind suggest turbulence scatters and redistributes them, prolonging intensity. Understanding these effects is crucial for accurate cosmic ray data interpretation.

The study highlights that interactions of CMEs play a significant role in determining their impact on Earth, highlighting that their initial speeds, while similar, are less influential. Besides, the EUHFORIA numerical model align with the findings of the GFZ German research center, this implies that EUHFORIA has also the capability to compute and potentially forecast the impact of CMEs on the Earth.