A new method to retrieve relative humidity profiles from a synergy of Raman lidar, microwave radiometer and satellite

Abstract. Precise continuous measurements of relative humidity (RH) vertical profiles in the troposphere have emerged as a considerable scientific issue. In recent years, a combination of diverse ground-based remote sensing devices has effectively facilitated RH vertical profiling, leading to enhancements in spatial resolution and, in certain instances, measurement accuracy. This work introduces a newly developed approach for obtaining continuous RH profiles by integrating data from a Raman lidar, a microwave radiometer, and satellite sources. RH profiles obtained using synergistic approaches are subsequently compared with radiosonde data throughout a five-month observational study in China. Our suggested method for RH profiling demonstrates optimal concordance with the best correction coefficients R of 0.90 in Huhehaote (HHHT), 0.91 in Yibin (YB) and 0.93 in Qingyuan (QY), respectively. Accordingly, the mean bias (MB) reached the lowest values of 4.93 % in HHHT, 2.63 % in YB and 2.40 % in QY. The mean value of RH decreased with height and presented seasonal characteristics in QY. Finally, the RH height-time evolution in a convective case was analyzed. This study firstly integrates satellite data into ground-based measurement to provide information on RH profiles in China, which may aid in further evaluating their regional characteristic and their impacts on the local ecosystem.