## 3 Results
### The Occurrence Rate of IBIs during Different Types of Geomagnetic Storms
The occurrence rates of IBIs at the altitudes of Swarm A and C satellites are the maximum (83%)  
Figure 2: Global distributions of IBI events during super, intense, and moderate storms from top to bottom observed by Swarm A, B, and C in red, blue, and cyan dots, respectively, on the left. The dashed line corresponds to the \(\pm\)20\({}^{\circ}\) latitude from the dip equator. The right column is its corresponding IBI occurrence number in the northern and southern hemispheres in magenta and black bars, respectively. during moderate storms. For all types of storms, the majority of IBI events are observed within the longitudinal sector (0\({}^{\circ}\) E and 110\({}^{\circ}\) W) or within the location of the SAA. Figure 4a,b introduces the geographic locations of IBIs observed at different heights according to different storm types. Super, intense, and moderate storms are marked in red, black, and blue dots respectively. These IBIs are superimposed on a map of the total Earth's main magnetic field that was calculated from the CHAOS\(-\)7.4 model at 450 km altitude [58]. The total Earth magnetic field varies up to 60,000 nT as indicated by the color bar index at the rightmost of Figure 4b. The map shows that the minimum magnetic field values of the Earth are located over the Atlantic Ocean between Africa and South America (called SAA). A comparison between the geomagnetic map and the number of IBIs shows that the number of IBIs increases dramatically over SAA at both altitudes. Figure 3: The occurrence number of IBIs with respect to geographic longitude observed during (**a**) super, (**b**) intense, and (**c**) moderate storms. The IBIs observed by Swarm A, B, and C are marked in red, blue, and cyan bars, respectively. Figure 4c,d illustrates the number of events at each altitude with respect to longitudes. It clearly shows that at higher altitudes (>500), the majority of events are located within \(\pm\)20\({}^{\circ}\) magnetic latitudes and grouped at longitudes between 10\({}^{\circ}\) E and 80\({}^{\circ}\) W. In contrast, at lower heights (<470 km), events are spread over larger latitudes (30\({}^{\circ}\) N-40\({}^{\circ}\) S) and longitudes (30\({}^{\circ}\) E-120\({}^{\circ}\) W). A comparison between Figure 4c,d shows that the number of IBI events at low altitudes (<470 km) is larger than those observed at higher altitudes (>500 km). Moreover, intense IBIs at high altitudes are only located in a very limited latitude (\(\pm\)10\({}^{\circ}\)) and longitudes 20\({}^{\circ}\) W to 60\({}^{\circ}\) W. At low altitudes, the minimum number of IBIs are associated with intense storms and are scattered over a broad range of latitudes and longitudes, while the maximum number of IBIs are observed during moderate storms. Also, Figure 4c, d shows that the maximum number of IBIs are observed at longitudes 20\({}^{\circ}\) E to 120\({}^{\circ}\) W. Figure 4c shows that at high altitudes, the numbers of IBIs are comparable during the three types of storms. Comparing the number of IBIs during super storms in Figure 4c,d at both altitudes shows that their corresponding IBI numbers at high altitudes are larger than those at low altitudes. It means the probability of finding IBIs at high altitudes increases with the increase in the level of geomagnetic activity as shown in Figure 4c. Also, the probability of observing IBIs at higher altitudes decreases with the decrease in the geomagnetic activity level as shown in Figure 4d. The Local Time Variations of the Occurrence and the Duration Time of IBIs Observed during Different Types of Geomagnetic Storms  
The occurrence of IBIs with respect to local time during various types of storms is presented in Figure 5a-c. It is generally noticed that the majority of IBIs are observed between sunset and midnight (18:00-24:00 LT) and few events are observed from post-midnight until the early morning (24:00-06:00 LT).