Abstract
High frequency (HF) radio wave propagation depends on the ionosphere status which is changed with the time of day, season, and solar activity conditions. In this research, ionosonde observations were used to calculate the values of maximum usable frequency (MUF) the ionospheric F2- layer during strong geomagnetic storms (Dst ≤ -100 nT) which were compared with the predicted MUF for the same layer by using IRI-16 model. Data from years 2015 and 2017, during which five strong geomagnetic storms occurred, were selected from two Japanese ionosonde stations (Kokubunji and Wakkanai) located at the mid-latitude region. The results of the present work do not show a good correlation between the observed and predicted MUF values for F2- layer during the selected events of strong geomagnetic storms at these stations. Thus, there is a further need to improve the IRI-16 model for better matching with the observations during strong geomagnetic storms.
Highlights
The High frequency (HF) (3-30 MHz) radio wave is very important in communications because it has low cost and can be sent over long distances, with stations that are easy to set up
In the initial step, attempts were made to calculate the values of maximum usable frequency (MUF) from observations, which were verified with the predicted MUF values using international reference ionosphere (IRI)-16 model
The results show a mismatch between observed and predicted values of MUF during the day, in which the strong geomagnetic storms occurred, and for the two latitudes selected (Kokubunji and Wakkanai)
Summary
The HF (3-30 MHz) radio wave is very important in communications because it has low cost and can be sent over long distances, with stations that are easy to set up. The F2 layer of the ionosphere is responsible for radio communications due to its presence throughout the day. This layer carries approximately all nighttime radio wave propagation all over the world for long distances, depending on the height of the layer [4, 5]. Other researchers studied the ionosphere conditions with geomagnetic storms. In 1997, found a rapid collapse in midnight ionospheric F layer electron density during severe geomagnetic storms [11]. Kouris and Fotiadis [12,13,14] conducted many types of research related to daily and hourly variability of ionospheric parameters and their variation with the latitude
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
