Observational data indicate increasing trends of surface ozone (O₃) in China, despite emission controls that have resulted in reductions of precursor emissions. Here, we explore the cause of this contradiction, through analysis of surface observations (2014–2019) in China and historical observation record in the United States (US, 1990–2019). Our observation‐based analysis indicates that the reductions of nitrogen oxides (NO_x) emissions led to increase of surface O₃ in North China Plain (NCP) and Yangtze River Delta (YRD) of around 8 ppb. However, NO_x controls resulted in shift of O₃ chemical regimes over NCP and YRD, with turning points between NO_x‐ and volatile organic compound (VOC)‐limited regimes around 2019, while model simulations suggest transitional or NO_x‐limited regimes over the rest of China. The impacts of high fine particles (PM_2.5) on O₃ formation has declined because of the reduction of PM_2.5 concentrations. Stricter NO_x controls can mitigate O₃ pollutions over industrialized areas in China.

Over the Tibetan Plateau, solar heating often produces strong convective instability in the atmosphere. Using 3 years (1998–2000) of Tropical Rainfall Measuring Mission (TRMM) precipitation radar data, our investigations revealed a tower mast shape of precipitation over the Plateau in both height‐longitude and height‐latitude cross‐sections. High rain rate center over the Plateau is located above 6km as a tower penetrating into the mid‐troposphere against the nearby background, implying a unique latent heating source injecting directly to the middle atmosphere. Results indicate that there are more isolated rain cells over the Plateau than its nearby regions, and the strongest diurnal cycle of rainfall existing over the Plateau with a peak around 1600 and a valley around 0500 local time, indicating the dominance of convective clouds caused by solar heating. It is also found that the TRMM algorithm might have misclassified weak convections as stratiform rains.

Rain-type statistics derived from Tropical Rainfall Measuring Mission (TRMM) precipitation radar (PR) standard product show that some 70% of raining pixels in the central Tibetan Plateau summer are stratiform—a clear contradiction to the common knowledge that rain events during summer in this region are mostly convective, as a result of the strong atmospheric convective instability resulting from surface heating. In examining the vertical distribution of the stratiform rain-rate profiles, it is suspected that the TRMM PR algorithm misidentifies weak convective rain events as stratiform rain events. The possible cause for this misidentification is believed to be that the freezing level is close to the surface over the plateau, so that the ground echo may be mistakenly identified as the melting level in the PR rain classification algorithm.