## 2 Data Collection
### Physical Parameters Affecting Ionospheric Scintillation  
In this research, the parameters affecting the ionosphere, which can cause ionospheric scintillation, are used as inputs of the GANN. In order to study the ionospheric scintillation, different parameters such as the maximum F2 layer height (in Km) and vertical drift velocity (in Km/s) should be used along with other parameters such as solar flux F10.7, the sunspot number, and the international geomagnetic index \(K_{P}\). The behavior of ionospheric phenomena throughout the year can be divided into three seasons, i.e., the summer solstice, winter solstice, and equinox. Months can be categorized as follows: January, February, November, and December as the months of the winter solstice, May, June, July, and August as the months of the summer solstice, and March, April, September, and October as the equinox months. Therefore, we tried to select a month from each of the seasons and perform modeling and prediction for a thirty-day period. In the present study, January, March, and June in 2017 were used as input data for the initial GANN modeling. Among these parameters, the two parameters of the maximum height and the vertical drift velocity of the F2 layer directly affect the F2 layer, which is the main layer of the ionospheric scintillation phenomenon [22]. In fact, the plasma instability growth rate, which can cause ionospheric scintillations, is due to factors such as the neutral ion collision frequency (\(V_{in}\)), the intensity of the electric field (\(E\)), and the electron density gradient (\(\Delta n\)) of the F2 layer. The plasma instability growth rate can be represented as follows [36]:  
\[\gamma\ =\ \frac{\Delta n}{n}(\frac{E}{B}\ +\ \frac{g}{V_{in}})\ -\ \beta \tag{7}\]  
where \(B\) represents the intensity of the magnetic field of the earth, \(g\) indicates the gravity of the earth, and \(\beta\) denotes the rate of ion recombination in the ionosphere. These parameters create conditions or factors that increase the growth rate of instability in the ionosphere [6]. The F2 peak electron density height, hmF2, and the vertical drift velocity of the F2 layer used in this study were derived from the GUAM Ionosonde Portable Sounder (13.58 E, 144.86 N, 201.922 H) with a 15-min observation time interval. Ionosonde data used in this research are employed with 25 kHz as the obtained frequency. The information related to this station can be obtained from the NOAA site at [[https://www.ngdc.noaa.gov/stp/iono](https://www.ngdc.noaa.gov/stp/iono)]([https://www.ngdc.noaa.gov/stp/iono](https://www.ngdc.noaa.gov/stp/iono)) (access on 27 March 2021). The vertical drift velocity of the F2 layer can be calculated by computing the variation in the F2 layer with respect to the measured time interval as follows:  
\[vdF\ =\ \frac{\Delta hF}{\Delta t} \tag{8}\]  
where \(\Delta hF\) is the difference in height in two successive observation epochs, \(vdF\) is the vertical drift velocity of the F2 layer in km/s, and \(\Delta t\) is the time observation interval, which is five minutes in this study. The input parameter F10.7 indicates the solar flux measured at the wavelength of 10.7 cm, which is used to determine the solar activity [1]. Severe ionospheric scintillations occur in periods in which solar activity is at the highest level. However, ionospheric scintillations have lower values in periods with low solar activity [22]. These values are available at the National Geophysical Data Center at [[https://www.ngdc.noaa.gov/](https://www.ngdc.noaa.gov/)]([https://www.ngdc.noaa.gov/](https://www.ngdc.noaa.gov/))(access on 27 March 2021). The sunspot number is another parameter used in modeling, which is directly related to the magnetic field of the sun. The obtained data imply that the magnetic field created around the sunspots is 1000 times stronger than that of the sun's magnetic field [37].