## 3 Results
### Examination of the Simulations with Gpm-Co Dpr
All WRF simulations tended to overestimate both the intensity and the vertical extent of the reflectivity factor field, triggering exaggeratedly strong convective updrafts, and most cloud tops attained altitudes of 10-11 km. Nevertheless, the ECMWF-based experiments proved to be more skillful and showed better agreement with the DPR profile in terms of main features of the system's mesoscale organization, succeeding in accurately creating the two sides of the eyewall, distinguishing the main intense rainband from the outer band of weaker rain to the northwest, and even the narrow and light precipitation area to the southeastern side. Most GFS-based simulations, instead, realistically represented the southeastern portion of the eyewall, but they tended to underestimate the northwestern side; furthermore, they were not able to predict the main rainband with sufficient consistency and homogeneity (or they did, but placed it too far to the northwest). These results show the important role  
Figure 7: Vertical cross-sections in the SW–NE direction of Ku-band radar corrected reflectivity (dBZ) at 10:30 p.m. UTC 17 September 2020 for all simulations (**a–h**) and as observed by the GPM-CO DPR overpass at 10:31 p.m. UTC (i). Their relative location is indicated in Figure 5i by the blue dashed line B (note that panel (i) is not centered around the TLC’s eye center but the other panels are). The vertical axes are in km. of IBCs in the simulation of the characteristics of Ianos. The difference between ECMWF and GFS models and data assimilation systems, as well as the different horizontal and vertical resolutions of the global models, had a role in determining the WRF sensitivity to IBCs. It was not possible to separate these factors, with the global model dataset available. Interestingly, only the WDM6 experiments (Figure 6b,f) seemed to adequately simulate the bright band in the outer rainbands. Since radar observations located the most active area of Ianos in its southwestern quadrant and most of the simulations performed poorly at forecasting the northeastern part of the eyewall at 5 km height, Figure 7 shows the vertical cross-sections of the reflectivity for the SW-NE direction. The vertical profile crosses the eye for a length of 200 km for the simulations and 160 km for the observations, as shown in Figure 5i by the blue dashed line B (in the latter case, it is shorter on its southwestern side because it was out of the DPR swath field). The DPR vertical profile (Figure 7i) reveals that the most intense observed convection was located in the southwestern eyewall, with a reflectivity peak of 50.3 dBZ around 3-4 km and values of >42 dBZ extending up to 5 km, with cloud tops reaching about 11 km. On the northeastern side of the eye, two stratiform rainbands can be identified, the one on the eyewall (exhibiting also the bright-band signature at a height of 3.5-4 km) and an outer one with a lower vertical extension. All experiments could reproduce reasonably well the southwestern high reflectivity eyewall region and approximate vertical extension. On the other hand, only the Thompson and Morrison schemes succeeded in predicting at least part, although of weaker intensity, of the northeastern eyewall and outer rainband. In particular, Thompson ECMWF appeared to be the only experiment that predicted a consistent northeastern eyewall, although it was still positioned too far relative to its medicane center. Subsequently, in addition to the analyses of the single cross-section of radar reflectivity, we further exploited the DPR's vertical resolution by performing a more statistical analysis of the medicane's three-dimensional structure of the radar reflectivity field. This was achieved through the calculation of the contoured frequency by altitude diagrams (CFADs; [58]). Figure 8 shows the predicted (a-h) and observed (i) reflectivity frequencies binned every 2 dBZ, with a vertical resolution of 250 m within a radius of 200 km from the minimum MSLP center.