The present work shows the preliminary results from the analysis for developing an ionospheric scale index map based on the Disturbance Ionosphere indeX (DIX). This index aims to target all the different user groups affected by ionospheric disturbances, for example, the navigation, positioning, and satellite communication users, in a simple and straightforward approach. Therefore, we used the vertical total electron content (VTEC) over South America to calculate the total electron content (TEC) maps covering latitudes from 60°S to 20°N and longitudes from 90°W to 30°W, with 0.5°× 0.5°resolution. Afterward, the DIX maps are obtained to reveal the variation of the TEC over an average quiet ionosphere background. In order to illustrate the use of the map index, the ionospheric disturbances after and during the 17-23 December 2015 intense geomagnetic storm and the 2015 Saint Patrick magnetic storm are discussed, highlighting the disturbances in the DIX at different latitudinal ranges and under different magnetic conditions.

During disturbed periods, E region electric fields can cause anomalous Es layer behavior, which is observed in the digital ionosonde data. To investigate the influence of these electric fields in the Es layer development, we analyzed a set of 20 magnetic storms from 2015 to 2018 over Boa Vista (BV, 2.8°N, 60.7°W, dip ∼18°), São Luís (SLZ, 2.3°S, 44.2°W, dip ∼8°), and Cachoeira Paulista (CXP, 22.41°S, 45°W, dip ∼35°). The electric field zonal components during the main and recovery phases of each magnetic storm are computed to study the corresponding characteristics of these Es seen in ionograms. Additionally, a numerical model (MIRE, Portuguese acronym for E Region Ionospheric Model) is used to analyze the Es layer dynamics modification around disturbed times. Using observation data and simulations, we were able to establish a threshold value for the electric field intensity for each region that can affect the Es layer formation. The results sustain that the strong Es layer in BV can be an indicator of the disturbed dynamo event. At SLZ, on the other hand, the Es layers are affected by the competition mechanisms of their formation, as equatorial electrojet irregularities and winds, during the main phase of the magnetic storm. Over CXP, the Es layer dynamics are dominated by the wind shear mechanism. Finally, this study provides new insights into the real impact of the electric field in the Es layer development over the Brazilian sector. Thus, our results lead to a better understanding of the underlying mechanisms related to the Es layer formation and dynamics.

The present work is the first of a two‐part paper on the Embrace Magnetometer Network. In this part, we present the new Embrace Magnetometer Network (Embrace MagNet) in South America, which is originally planned to cover most of the eastern portion of the Southern America longitudinal sector by installing and operating fluxgate magnetometer stations. We discuss the purpose and scientific goals of the network, associated with aeronomy and space weather. We provide details on the instrumentation, location of the sensors, sensitivity matching process, gain matching process, and magnetometer installation. In addition, we present and discuss details about the data storage, near‐real time display, and availability.

Abstract. This work presents an analysis of the ionospheric responses to the solar eclipse that occurred on 14 December 2020 over the Brazilian sector. This event partially covers the south of Brazil, providing an excellent opportunity to study the modifications in the peculiarities that occur in this sector, as the equatorial ionization anomaly (EIA). Therefore, we used the Digisonde data available in this period for two sites: Campo Grande (CG; 20.47∘ S, 54.60∘ W; dip ∼23∘ S) and Cachoeira Paulista (CXP; 22.70∘ S, 45.01∘ W; dip ∼35∘ S), assessing the E and F regions and Es layer behaviors. Additionally, a numerical model (MIRE, Portuguese acronym for E Region Ionospheric Model) is used to analyze the E layer dynamics modification around these times. The results show the F1 region disappearance and an apparent electronic density reduction in the E region during the solar eclipse. We also analyzed the total electron content (TEC) maps from the Global Navigation Satellite System (GNSS) that indicate a weakness in the EIA. On the other hand, we observe the rise of the Es layer electron density, which is related to the gravity waves strengthened during solar eclipse events. Finally, our results lead to a better understanding of the restructuring mechanisms in the ionosphere at low latitudes during the solar eclipse events, even though they only partially reached the studied regions.

The Embrace Magnetometer Network (Embrace MagNet) uses a series of magnetometers over South America to monitor the Earth's space environment and to study space weather. One of the common techniques used to study the effects of the magnetic disturbances in the globe is through the quiet day curve (QDC) of the geomagnetic field components. These types of QDC are calculated based on geomagnetic field data collected by magnetometers in the five quietest days for each month at each station. Thus, we developed and implemented an empirical model based on the QDC H component obtained by the Embrace MagNet. This model ought to be used as a prediction device when data are not available. The proposed algorithm is a function of the solar activity, the day of the year, and the universal time, which was adjusted based on 12 stations across to the South America sector between 2010 and 2018. Our results show that the values computed by this model are in good agreement with the observational data for the QDC. Finally, it is essential to mention that the QDC model presented in this study is the only available predicting tool of the Embrace MagNet stations to date, providing data with a high confidence level in the Brazilian sector.