An hourly scale precursor of inland earthquakes (EQs) is revealed in this paper. Several EQ cases in China have been reported. As indicated by a table listing 23 inland EQs and their shock time, epicenter location, magnitude, near-epicenter weather conditions, precursor start time and precursor duration, when the weather conditions are fair near the epicenter, an anomalously negative atmospheric electrostatic signal is readily observable approximately 2–48 h before the EQ occurs. Moreover, a successful single-station alarm for nearby moderate-magnitude EQs is demonstrated, and a possible mechanism for the precursor signal is proposed. The change in the electrostatic field during an EQ process is explained as the release of radioactive gases from the subsurface into the atmosphere via large (regional-scale) preexisting microfractures in the rock at the source depth. These gases considerably ionize the atmosphere, and the separated positive and negative ions establish a special macroscopic electric field. The final critical stage of 2–48 h before an EQ may indicate a stable tectonic process.

Geomagnetic storms have a significant impact on Earth’s magnetosphere and ionosphere, as well as on the global atmospheric circuit. This study focuses on investigating the anomalous variations in the vertical atmospheric electric field at eight mid-latitude and low-latitude stations during a mega-geomagnetic storm on 24 April 2023. The majority of stations observed vertical atmospheric electric field increases, while only three nearby stations exhibited vertical atmospheric electric field decreases. The analysis revealed that vertical atmospheric electric field changes ranged from 19 to 370 V/m, and the time differences between extreme vertical atmospheric electric field values and the minimum Dst value ranged from 0 to 5.3 h. Other response patterns to this super magnetic storm at different latitudes are summarized, and the physical mechanisms of different effects of magnetic storms on the electric fields of stations at different latitudes are also discussed.

The variability in the atmospheric electric field is modulated by a combination of solar activities, meteorological activities, and geological conditions. A foundational dataset of the daily variations in the fair-weather atmospheric electric field is established in this study, and several examinations are conducted into the details of these variations in particular regions. This paper is organized as follows. First, the researchers count the datasets of daily variations to the atmospheric electric field on fair-weather days from 1 March–1 August 2022 at Zhongshan Chinese Station in Antarctica and Changping Station in Beijing. Then, the average daily variation in the atmospheric electric field on 40 fair-weather days in Antarctica is shown and the variations are compared with the average curve of 37 fair-weather days in Beijing during the same time period. Finally, the three main differences between these variations, their possible reasons, and a reasonable error analysis are clarified and discussed at the end of this paper.

In fair weather, the vertical atmospheric electric field is oriented downward (positive in the earth surface ordinate system) in the global atmospheric circuit. Some researchers have revealed the unique phenomenon whereby once an upward vertical atmospheric electric field is observed in fair weather, an earthquake (EQ) follows within 2–48 h regardless of the EQ magnitude. However, the mechanism has not been explained with a suitable physical model. In this paper, a physical model is presented considering four types of forces acting on charged particles in the air. It is demonstrated that the heavier positive ions and lighter negative ions are rapidly separated. Finally, a reversed fair weather electrostatic field is formed by the above charge separation process. The simulation results have instructive significance for future observations and hazard predictions and still need further research.

The atmospheric electric field is an important physical parameter used to study the state of charge density distribution between the earth and the ionosphere, and its daily variation characteristics reflect the underlying atmospheric electrical properties in a region. In this paper, we used atmospheric electric field data from three global observation stations (the Xanthi station, the Zhuanghe station, and the University of Reading station) from January to December 2021 and then combined these data with meteorological data and geomagnetic activity data to filter the fair-day atmospheric electric field data and plot the average fair-weather atmospheric electric field curve. Then, we compared different sunrise and sunset times and PM 2.5 concentrations, analyzed the seasonal differences for each station, the differences among the three stations, and the difference between their curves and the Carnegie curve, and finally concluded that the difference among them showed positive correlations with PM 2.5 concentrations. The other possible reasons and the entire shape of the average fair-weather atmospheric electric field curve for a defined station are not affected by the season, including the location of peaks and valleys, and the overall variation have been also revealed.

The near-surface atmospheric electrostatic field plays a pivotal role in comprehending the global atmospheric circuit model and its influence on climate change. Prior to delving into the intricate interplay between solar activities, geological activities, and atmospheric electric field, a comprehensive examination of the diurnal fair atmospheric electric field’s baseline curve within a specific region is essential. Based on the atmospheric electric field network monitoring in Yunnan Province in the year 2022, this study systematically investigated the distribution of the atmospheric electric field under both fair-weather and disturbed weather conditions at a quadrilateral array encompassing Chuxiong Station, Mouding Station, Lufeng Station, and Dali Station. The primary focus was on elucidating the variations in the daily variation curves of fair atmospheric electric fields and conducting a comparative analysis with the Carnegie curves. The possible reasons for the differences among them are also discussed in this study, but more observational evidence is required to confirm the specific causes in the future.