Development of an Empirical Model for Estimating the Quiet Day Curve (QDC) Over the Brazilian Sector

Abstract

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.

Evaluation of the Solar Quiet Reference Field (SQRF) model for space weather applications in the South America Magnetic Anomaly

“…We used the Solar Quiet Reference Field (SQRF) model to estimate and predict the Sq-H field in the SAMA region (Chen et al 2020), an empirical model based on the daily variation of the horizontal field obtained by magnetic field data collected from Embrace MagNet (Denardini et al 2018a). Such a model reveals the climatology of geomagnetic quiet daily variation across South America.…”

“…In the present study, we attempt to develop an estimating and predicting tool for obtaining the solar quiet daily variation of the geomagnetic field at the SAMA. The analysis is based on the empirical model developed by Chen et al (2020). This predicting tool estimates the Sq-H field for a region based on a linear interpolation method on the SQRF parameters of two magnetic stations, both close to the same meridian.…”

Evaluation of the Solar Quiet Reference Field (SQRF) Model for Space Weather Applications in the South America Magnetic Anomaly

“…Some ionospheric indices for the space weather applications using ground-based instrumentation and satellite data developed on the Embrace Program can be found in Resende et al (2019) and Denardini et al (2020). Also, several authors use magnetic field measurements to estimate the magnitude of disturbed and storm-time periods driven by solar events (e.g., Klausner et al, 2016;Bolzan et al, 2018;Denardini et al, 2018b).…”

“…In this study, we attempt to establish an estimating and predicting tool for obtaining the solar quiet daily variation of the geomagnetic field in the SAMA region. The analysis performed is based on the empirical model developed by Chen et al (2020). This predicting tool estimates the Sq-H field for a region based on a linear interpolation method on the SQRF parameters of two magnetic stations, both close to the same meridian.…”

“…∆ * is the Sq-H field amplitude obtained from the model. Details about the coefficients, as well as the description of all fitting equations of parameters above are given in Chen et al (2020).…”