## 3 Results  
### Characteristics of the Atmospheric Vertical Structure  
In this section, the characteristics of the atmospheric vertical structure obtained from the MWR, namely, the temperature (\(T\)), vapour density (\(VD\)), and relative humidity (\(RH\)) profile at 58 sampling heights, were verified using radiosonde observations in the early morning, at 7:00 (UTC+8), and in the evening, at 19:00 (UTC+8). Figure 4 shows that the values of \(T\) and \(VD\) for the Qinghai-Tibet Plateau during the EAWM period decreased as the sampling height (\(H\)) increased. The Pearson correlation coefficient (CC) between the RAOB and MWR profiles was 0.99. There were almost linear trends for the \(T\)-\(H\) profile and exponential trends between \(VD\) and \(H\). The maximum and minimum values of temperature obtained from RAOB and MWR were 268.83 and 217.77 K, respectively. The \(T\) values under snowy conditions were somewhat smaller than those under sky days, approximately 1.18 K at \(t\) = 7:00 (UTC+8) and 0.46 K in the evening at \(t\) = 19:00 (UTC+8). For \(VD\) obtained by RAOB and MWK, the \(VD\) values were in the range of 2.11 and 3.82 g/m\({}^{3}\) near the ground. \(VD\) values on snowy days were 0.51 and 1.30 g/m\({}^{3}\) larger than those under clear conditions at \(H\) = 50 m, respectively. For the \(RH\) profile, the \(RH\) appeared to generally decrease with increasing \(H\) under snowy conditions but showed different trends for clear days. The corresponding CC value in 58 layers between the MWR and RAOB was 0.99 for clear days and 0.96 for snowy days. At \(t\) = 7:00 (UTC+8), the \(RH\) values under clear days (snowy sky) decreased from 67.4% (91.87%) near the ground to 9.78% (12.5%) at \(H\) = 10 km. At \(t\) = 19:00 (UTC+8), \(RH\) values under snowy conditions generally decreased from sampling heights. However, for sky days, the \(RH\) values first increased from 48.28% near the ground to 57.13% at \(H\) of 5.5 km, and significantly decreased to 25.42% at \(H\) = 10 km. Figure 3: The framework of the article. Figure 4: _Cont._  
Figure 5 presents deviations between the MWR and RAOB at 58 sampling heights. The average \(T\) value derived from the MWR at 58 high levels was 0.13 K smaller than radiosonde observation in the early morning (\(t=7\):00) but 0.27 K larger in the evening (\(t=19\):00). The corresponding \(RMSE\) values were 0.82 K and 1.67 K, respectively. An accurate calibration of \(T\) with an \(MD\) error less than 0.5 K was crucial to provide confidence for the retrieval of \(VD\) and \(RH\) profiles. Figure 4: Comparison of temperature (**a,d**), vapour density (**b,e**), and relative humidity (**c,f**) profiles obtained from MWR and RAOB under clear-sky and snowy-sky conditions. Figure 5: \(Cont.\)  
For _VD_ values at higher levels (\(H>6\) km), the density profile derived from the MWR was close to that obtained from RAOB. For \(H\) less than 6 km, the _MD_ values of _VD_ under a snowy-sky environment were larger than those for clear days, with a peak value of 0.35 g/m\({}^{3}\). The _MD_ (and _RMSE_) values of _VD_ at \(t=7\):00 were \(-0.0096\) g/m\({}^{3}\) (0.111 g/m\({}^{3}\)) and 0.127 g/m\({}^{3}\) (0.243 g/m\({}^{3}\)) for clear-sky and snowy-sky conditions, respectively. At \(t=19\):00, both _MD_ and _RSME_ errors were larger than those in the morning, especially on snowy days. The _MD_ values for clear-sky and snowy-sky conditions were 0.24 g/m\({}^{3}\) and 0.32 g/m\({}^{3}\), with corresponding _RSME_ values of 0.34 g/m\({}^{3}\) and 0.33 g/m\({}^{3}\), respectively. Figure 5: Comparison of temperature bias (**a,d**), vapour density bias (**b,e**), and relative humidity bias (**c,f**) profiles obtained from MWR and RAOB under clear-sky and snowy-sky conditions. _RMSEs_ are marked by error bars. The decrease in MWR measurement accuracy during snowfall was mainly because the inversion method does not consider the influence of snow cover, and the snow cover at the radome increased the signal noise of the MWR measurement.