## 4 Results  
### Topside Effective Scale Height from Calibrated In Situ \(N_{e}\) Observations  
To highlight the time and spatial behavior of \(H_{0}\) values calculated through the procedure outlined in Section 3, we binned data in geographical coordinates for different diurnal and seasonal conditions. Since our dataset embraces only low solar activity conditions (F10.7\({}_{81}\)\(\leq\) 85 sfu), no solar activity sorting has been applied. Data were sorted in two  
Figure 3: Example of methodology employed for the topside \(N_{\mathrm{e}}\) profile modeling. The red point is the F2-layer peak anchor point, as modeled by IRI; the green point is the topside anchor point, as measured by CSES—01 (calibrated values); the blue curve is the topside \(N_{\mathrm{e}}\) profile, which was obtained via the modeled linear scale height. Anchor points, values, and linear scale height fit parameters are reported in the textbox. CSES—01 data were recorded on the 24 th of January 2020 at 12:55:10 UT—latitude = \(-\)26.88\({}^{\circ}\), longitude = 10.77\({}^{\circ}\), QD latitude = \(-\)35.95\({}^{\circ}\) for daytime conditions (\(\sim\)14:00 LT). bins in local time according to the CSES--01 orbital configuration. The process of seasonal sorting is the same as the one applied in Section 3.2. For each of these bins, data were sorted in bins 2\({}^{\circ}\)-wide in latitude and 4\({}^{\circ}\)-wide in longitude. The median value of \(H_{0}\) inside each geographical bin was considered. Figure 4 shows the geographical maps of median \(H_{0}\) values for the daytime sector. First column plots are \(H_{0}\) values obtained with CSES--01 calibrated \(N_{\rm e}\) values; second column plots are obtained with Swarm B calibrated \(N_{\rm e}\) values; while third column plots are \(H_{0}\) values obtained directly from COSMIC--1 RO topside profiles. COSMIC--1 \(H_{0}\) values are considered as the reference here because RO observations allow for the calculation of \(H_{0}\) by directly applying Equation (6) to \(H_{\rm Epstein}\) values calculated through Equation (7), without any assumption and use of modeled values. Figure 4: Geographical representation of median values of \(H_{0}\) for the daytime sector (\(\sim\)14:00 LT). First row plots (panels (**a**–**c**)) are for FMA = (February, March, April) months; second row plots (panels (**d**–**f**)) for MJJ = (May, June, July) months; third row plots (panels (**g**-**i**)) for ASO = (August, September, October) months; and fourth row plots (panels (**j**–**l**)) for NDJ = (November, December, January) months. First column plots (panels (**a,d,g,j**)) are \(H_{0}\) values obtained with calibrated CSES—01 and IRI-modeled data; second column plots (panels (**b,e,h,k**)) are corresponding values obtained with calibrated Swarm B and IRI-modeled data; third column plots (panels (**c,f,i,l**)) are those obtained with COSMIC—1-measured \(N_{\rm e}\) data by radio occultation. Color bar scale is the same across all panels. The solid black curve in each plot represents the geomagnetic equator. Daytime \(H_{0}\) values show an absolute maximum in a narrow belt around the geomagnetic equator (highlighted by a solid black curve in the maps), while much lower values are found outside of this region. \(H_{0}\) values are slightly higher at the highest latitudes. Although the three datasets show similar spatial patterns, they differ in magnitude near the geomagnetic equator, where values modeled using both CSES--01 and Swarm B observations show much higher values than those obtained through COSMIC--1. Specifically, \(H_{0}\) values from CSES--01 reach values higher than 150 km in MJJ and ASO months in the range of longitudes between 60\({}^{\circ}\)E and 120\({}^{\circ}\)E and between 60\({}^{\circ}\)W and 120\({}^{\circ}\)W. Similar longitudinal variations are also seen by Swarm B and COSMIC--1, albeit with lower values in magnitude. The orbital configuration of CSES--01 turns out to be well-suited for studying longitudinal variations.