In the present work, we evaluate the accuracy of the Solar Quiet Reference Field (SQRF) model for estimating and predicting the geomagnetic solar quiet (Sq) daily field variation in the South America Magnetic Anomaly (SAMA) region. This model is based on the data set of fluxgate magnetometers from 12 magnetic stations of the Embrace Magnetometer Network (Embrace MagNet) from 2010 to 2018. The model predicts the monthly average horizontal field of the geomagnetic quiet (Sq-H) daily variation solving a set of equations for the specified geographic coordinates in terms of the solar cycle activity, the day of the year, and the universal time. We carried out two comparisons between the prediction and observational data of the Sq-H field. The first part attempts to evaluate the accuracy for estimating the Sq-H field over Medianeira (MED, 25.30° S, 54.11° W, dip angle: − 33.45°) by using linear interpolation on the SQRF coefficients and comparing it with the data collected from April to December in 2018. None of the datasets collected at MED is part of the dataset used to build the SQRF model. The second part of the analysis attempts to evaluate the accuracy for predicting the quiet daily field variation over Cachoeira Paulista (CXP, 22.70° S, 45.01° W, dip angle: − 38.48°). The dataset collected at CXP before the period analyzed in the present work is part of the dataset used to build the SQRF model. Thus, the prediction accuracy is tested using magnetic data outside the time interval considered in the model. The prediction results for both locations show that this empirical model’s outputs present a good agreement with the Sq-H field obtained from the ground-based magnetometer measurements. The accuracy of the SQRF model (high correlation, r > 0.9) indicates a high potential for estimating and predicting geomagnetic quiet daily field variation. Concerning space weather applications, the model improves the scientific insight and capability of space weather prediction centers to predict the variability of the regular solar quiet field variation as reference conditions, which may include areas with no measurements.

在当前的工作中，我们评估了太阳安静参考场（SQRF）模型的准确性，该模型用于估计和预测南美磁异常（SAMA）区域的地磁太阳静（Sq）日场变化。该模型基于2010年至2018年Embrace磁强计网络（Embrace MagNet）的12个磁站的磁通门磁强计的数据集。该模型预测了地磁静默（Sq-H）每日变化的月平均水平场。根据太阳活动周期，一年中的某一天和世界时间指定的地理坐标的一组方程式。我们在Sq-H场的预测和观测数据之间进行了两次比较。第一部分试图评估估计Medianeira上Sq-H场的准确性（MED，25.30°S，54。通过在SQRF系数上进行线性插值并将其与2018年4月至12月收集的数据进行比较，将11°W，倾角：− 33.45°）进行比较。MED收集的所有数据集都不是用于构建SQRF的数据集的一部分模型。分析的第二部分尝试评估在Cachoeira Paulista上进行的安静日场变化预测的准确性（CXP，22.70°S，45.01°W，倾角：− 38.48°）。在本工作中分析的期间之前，在CXP上收集的数据集是用于构建SQRF模型的数据集的一部分。因此，使用模型中考虑的时间间隔以外的磁数据测试预测准确性。两个位置的预测结果表明，该经验模型的输出与从地面磁力计测量获得的Sq-H场呈现出良好的一致性。r  > 0.9）表示估计和预测地磁静磁场日变化的巨大潜力。关于太空天气的应用，该模型提高了太空天气预报中心的科学见解和能力，可以预测常规太阳安静场变化的可变性作为参考条件，其中可能包括没有测量的区域。