Modeling and Forecasting Ionospheric foF2 Variation in the Low Latitude Region during Low and High Solar Activity Years

Abstract

Prediction of ionospheric parameters, such as ionospheric F2 layer critical frequency (foF2) at low latitude regions is of significant interest in understanding ionospheric variation effects on high-frequency communication and global navigation satellite system. Currently, deep learning algorithms have made a striking accomplishment in capturing ionospheric variability. In this paper, we use the state-of-the-art hybrid neural network combined with a quantile mechanism to predict foF2 parameter variations under low and high solar activity years (solar cycle-24) and space weather events. The hybrid neural network is composed of a convolutional neural network (CNN) and bidirectional long short-term memory (BiLSTM), in which CNN and BiLSTM networks extracted spatial and temporal features of ionospheric variation, respectively. The proposed method was trained and tested on 5 years (2009–2014) of ionospheric foF2 observation data from Advanced Digital Ionosonde located in Brisbane, Australia (27°53′S, 152°92′E). It is evident from the results that the proposed model performs better than International Reference Ionosphere 2016 (IRI-2016), long short-term memory (LSTM), and BiLSTM ionospheric prediction models. The proposed model extensively captured the variation in ionospheric foF2 feature, and better predicted it under two significant space weather events (29 September 2011 and 22 July 2012).

New Ways to Modelling and Predicting Ionosphere Variables

“…The authors found that the results obtained with the LSTM model give the best forecasting results.Tang et al (2022)[50] developed a global ionospheric TEC prediction model combining indirect forecasting methods from previous studies with the machine-learning Prophet model(Taylor and Letham, 2018) [51] to forecast a global TEC map for the next two days. The results show that the technique used forecast TEC with good accuracy.Bi et al (2022)[52] successfully used a state-of-the-art hybrid NN combined with a quantile mechanism to forecast foF2 parameter variations under low and high solar activity years including solar-terrestrial physics/space weather events.Reddybattula et al (2022) [53] adopted a long short-term memory (LSTM) DL network model to forecast TEC from GPS signals at a low-latitude location during about eight years of data for training and validation. One year of data was used for independent testing and forecasting of the TEC.…”