# Ionospheric Weather at Two Starlink Launches during Two-Phase Geomagnetic Storms
## 2 Data Processing Results
_GEC_ storm profiles are plotted in Figure 5(a1)-(d1) from 2 February (prestiorm day) to 5 February 2022: a1--JPLR, b1--CODE, c1--BUAG, d1--CASG. By the time of the Starlink launch at 18:13 UT on 3 February (thick vertical line), the 'true' data are available only for the prestorm day. The 'base' value presents the average _GEC_ during the prestorm day, 1d--1-day forecast for the day of launch, 2d--2-day forecast for the next day after the launch. The 1d (red) and 2d (green) curves with symbols present the forecast starting on the day of the launch, and similar curves without symbols denote the forecast starting on the next day after the launch when the geomagnetic storm is in progress. The detrended _GEC_ in Figure 5(a2)-(d2) (after subtraction of the base value from _GEC_ 'true' and 'forecast' data) clearly shows two 'true' positive _GEC_ storm phases on 3 and 4 February, followed by the negative phase on 5 February. The positive _GEC_ enhancements occur at the times of the increased neutral atmosphere density, with increased drag dooming most of the Starlink satellites [2; 3; 4; 5; 6; 7; 8]. We note a failure of _GEC_ 'forecast' to outline the 'true' storm effects observed in Figure 5(a1)-(d2). Similar nonconforming results are obtained between _GEC_ 'true' and 'forecast' profiles plotted from 6 July (prestiorm day) to 9 July 2022, including the Starlink S-49 launch at 13:11 UT on 7 July in Figure 6(a1)-(d3). Fortunately, all 53 Starlink S-49 satellites reached this time in their final orbit, because after the failure of S-36 experienced on 3-8 February 2022, the subsequent Starlink launches used a higher initial orbit [2], thereby avoiding a possible drag enhancement. The 'forecast' curves neither reproduce the positive phase of the _GEC_ storm on 7 July and from 00:00 to 05:00 UT on 8 July nor the nega  
Figure 5: Comparisons of 1- and 2-day forecast with ‘true’ _GEC_ profiles during the storm from 2 to 5 February 2022 including the Starlink S-36 launch (thick vertical line): _GEC_—upper panel, detrended _GEC_—lower panel. (**a1,a2**) JPLR; (**b1,b2**) CODE; (**c1,c2**) BUAG; (**d1,d2**) CASG. tive \(GEC\) excursion for the rest of the hours on 8 July except for a part of time fit between JPLR-JPLR1 and CODE-CODE1 in the forecast starting one day after the launch, JPLR-JPLR2, CODE-CODE2 and CASG-CASG2 produced on the day of the launch. The quantitative estimate of a correspondence between the 'true' and 'forecast' \(GEC\) storm data with \(R^{2}\) and \(RMS\) using Equations (4)-(6) is presented in Table 4 for the storms on 3-5 February and 7-9 July 2022. There is no reasonable conformity between the forecast (X) and true (Y) data from the four analysis centers all producing \(R^{2}\) negative results. The 'true' UQRG and real-time UADG results are compared with the Nearest-Neighbor (NN) method of 'forecast' for 6, 12, 18, 24 and 48 h in advance [15]. The results are plotted in Figure 7(a1,a2) from 2 February (prestorm day) to 5 February, and in Figure 7(b1,b2) from 6 July (prestorm day) to 9 July 2022. The Starlink launches of S-36 and S-49 are shown by a thick vertical line. An outstanding feature of Figure 7(a1,b2) is the usage of 'true'