## 3 Results
### Case on 31 March 2001  
The CME-driven shock accompanied by positive _Bz_ IMF has caused a strong compression of the magnetosphere, observed at the ground as SI of amplitude \(\sim\) 100 nT at -01:00 UT. Later, following _Bz_ turning southward, the main phase started at -4:20 and continued until 08 UT. At the storm maximum, the SYM-H index reached \(-\)437 nT. There was no increase in FEE flux during the entire period of 8 h, although it should be noted that there were only two satellites covering sectors 7-19 LT and 2-14 LT. The first FEE enhancement was observed during the early recovery phase at -09:45 UT or more precisely from 09:38 to 09:55 UT (Table 1, Figure 1). In the midnight sector, high-intensity fluxes were simultaneously observed in three energy channels: \(>\)30, \(>\)100, and \(>\)300 keV (a rare case). This means that the satellite was located exactly in the injection region. Figure 3 shows geomagnetic and solar wind conditions during the storm recovery phase from 8 to 11 UT on 31 March 2001. The upper panel presents the partial ring current index SMR-12 from SuperMAG [(49; 50)]. The SMR-12 index is derived based on the SYM-H index from ground-based magnetometers located within the magnetic local sector centered at noon (9 MLT to 15 MLT) and at geomagnetic latitudes between 50\({}^{\circ}\) S and 50\({}^{\circ}\) N. Measurements of horizontal component (X or H) of the geomagnetic field from two ground stations of the INTERMAGNET network at low latitudes are shown at the same panel. From 8 to 11 UT, the TAM station (22.8\({}^{\circ}\) N, 5.5\({}^{\circ}\) E) was at day (-8:11 LT) and TUC (32.2\({}^{\circ}\) N, 110.7\({}^{\circ}\) W) was at night (-0.5-3.5 LT). Lower panels present the solar wind parameters observed by the ACE upstream monitor: the total pressure \(P\) and three IMF components (_Bx_, _By_, _Bz_). The UT corresponds to the observations at the ACE location at -220 Re. The time delay is estimated at approximately 40 min at the solar wind plasma velocity of -600 km/s. It would be justified to take a slightly longer lag of 1 h, assuming that the characteristic operating time of the mechanism should be within 10-20 min. \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline
**Sat** & **LT** & **Time** & **Longitude** & _Je_ & _Je_ & **L-Shell** & **Comment** \\  & & **hh:mm** & \(\varphi^{\circ}\) & **\textgreater{}40 keV** & **\textgreater{}130 keV** & **(ACE or Wind Monitor Time)** \\ \hline \multicolumn{8}{c}{_31 March 2001_} \\ \hline P6 * & 2 & 09:45 & \(-\)120 & \(1\times 10^{6}\) & \(1\times 10^{6}\) & L \(\sim\) 1.12 & \begin{tabular}{c} \(\Delta\)p \textgreater{} 0 (\textasci{-}8:50 UT), magnetic \\ cloud, Bz \textgreater{} 0; early recovery \\ phase \\ \end{tabular} \\ \hline \multicolumn{8}{c}{_9 November 2004_} \\ \hline P5 & 6 & 21:10 & 137 & \(1\times 10^{7}\) & \(2\times 10^{6}\) & L \(\sim\) 1.05 & \
\begin{tabular}{c} \(\Delta\)p \textgreater{} 0 (20:30 UT), magnetic \\ cloud, Bz northward turning; \\ storm maximum \\ \end{tabular} \\ \hline \multicolumn{8}{c}{_10 May 2024_} \\ \hline P9 & 9 & 19:22 & \(-\)153 & \(7\times 10^{4}\) & \(5\times 10^{4}\) & L \(\sim\) 1.11 &
\begin{tabular}{c} \(\Delta\)p \textgreater{} 0 (\textasci{-}19:00 UT), interplanetary \\ sheath, Bz \textgreater{} 0; storm main phase \\ \end{tabular} \\ \hline \hline \end{tabular}  
* Enhanced flux was observed in the \textgreater{}300 keV channel.  
\end{table} 
Table 1: Characteristics of FEE fluxes. Just before the FEE-time, from about 9:15 to 9:35 UT, the geomagnetic field in the dayside increases rapidly by 70-90 nT, as measured by ground-based magnetometers (Figure 3), with the magnetic field increase typically being a response to the compression effect on the magnetosphere. At the night station TUC, the H-component shows a longer gradual increase with a local minimum around 9:15 UT followed by a rapid rise by 25 nT. Also, after this, three local peaks are observed which may be geomagnetic pulsations of the Pc5 type with a quasi-period 5-7 min.