Latent heat flux exchanges at the air–sea interface play important roles in the formation and development of tropical cyclones (TCs). Usually, the latent heat flux transferred from oceans to atmosphere increases during the intensification stages of the TCs. However, through analysing a number of TC cases over the South China Sea, it is found that the changes of latent heat flux exhibit different behaviours during the intensification stage of the TCs, depending upon their travelling pathways. The air–sea latent heat flux increases while the TCs are intensifying in open sea areas of the South China Sea. However, the latent heat flux decreases while the TCs are travelling over the narrow area between the Indo-China Peninsula and Hainan Island, even though the TCs are in their intensification stage. For the latter case, the decrease in latent heat flux F is accompanied by the decrease in surface winds due to the terrain frictions even though the upper troposphere winds are still increasing. Copyright © 2013 Royal Meteorological Society

Based on matched scans from the FY‐4A satellite's Advanced Geostationary Radiation Imager (AGRI) and the NASA/JAXA Global Precipitation Measurement (GPM) Core Observatory's Dual‐frequency Precipitation Radar (DPR), the microphysical mechanisms of the derived vertical evolution of cloud effective radius (R_e) and its correspondence with precipitation droplet growth modes are revealed in this study. The results show that there were two turning points in the R_e vertical evolution, which divided the R_e profile into solid‐phase, mixed‐phase, and liquid‐phase zones from top to bottom. There were also two turning points in the upper layer of DPR reflectivity, which showed good correspondence with R_e turning points in both height and physical sense. The main droplet growth modes in the three zones are nucleation/glaciation, deposition, and riming, respectively. The linkage between R_e vertical evolution and droplet growth modes would be useful in real‐time monitoring of cloud microphysical processes.

It is well known that global warming increases the atmospheric water vapor content, which results in substantial changes in the hydrological cycle. Using five observational data sets, the results show that an increasing trend of near‐surface water vapor pressure (AVP) over land and ocean was significant from 1975 to 1998, while such an increasing trend in AVP subsequently weakened from 1999 to 2019. This phenomenon is associated with decreased oceanic evaporation and land surface evapotranspiration in response to recent climate variations. One consequence of such a phenomenon is a large increase in near‐surface vapor pressure deficit (VPD), which in turn increases atmospheric demand for water vapor and thus aridity and drought over land. This result emphasizes the importance of water vapor change under global warming.