The rapid warming and consequent retreat of glaciers across the Tibetan Plateau (TP) have given rise to the debate on the ability of the atmospheric water supply to alleviate the depletion of surface water storage. We investigate long‐term changes in atmospheric water vapor balance across the TP using 40‐year fifth generation European Centre for Medium‐Range Weather Forecasts (ECMWF) (ERA5) reanalysis. Precipitation, water vapor convergence, and evaporation generally maintain an equilibrium but with different long‐term variation trends: 0.68, −0.18, and 0.69 mm/a, respectively. Results suggest the inability of the water vapor arriving from outside the TP to effectively replenish the surface water storage. Despite of huge changes in atmospheric water vapor balance during summer, the risk of water storage depletion is brought by other three seasons, especially the autumn. The climatology and long‐term trends of water vapor balance exhibit strong variation across the regions of TP. The surrounding areas of Yarlung Zangbo Grand Canyon experience sharp decrease in water vapor convergence, thus reducing precipitation. Moreover, increasing evaporation is expected to severely loss of surface water storage. For the Three Rivers Source Region with no significant changes in total precipitations, decrease in water transported from outside of TP overlaps increase in evaporation results in the possible depletion of surface water storage. Brahmaputra basin, inner TP, and Qilian Mountain exhibit significant wetting trends due to increases in both convergence of water vapor flux and evaporation. Above regional and seasonal characteristics of water vapor, balances across the TP are attributed by inhomogeneous variation of atmospheric heat source and complex changes of atmospheric circulations.

Rapid warming over the Tibetan Plateau (TP) has been associated with an increasing trend in atmospheric water vapor content, which is critical for recharging the Asian water tower. However, the mechanism associated with the wetting phenomenon remains unclear. Long‐term changes in moisture balance and precipitation (PRE) recycling processes are investigated using the ERA5 reanalysis from 1979 to 2019. The increasing trend over TP is mainly due to the summer water vapor trend with significantly increases over the western TP. Based on the moisture balance analysis, it is found that PRE, evaporation, and the convergence of moisture are all increasing over the western TP but decreasing over the eastern TP. Based on the dynamical PRE recycling model, the results suggest that both internal and external cycles contributes to the wetting over TP, with 63.87% and 36.13% contributions respectively. Further analysis found that the atmospheric heating source is also increasing over the western TP, which could shift the moisture transportation from east to west at the southern boundary of TP. The increasing moisture convergence could enhance PRE, and the enhanced latent heating in the mid‐atmosphere can further induced moisture convergence, which forms a positive feedback. However, an opposite situation occurred over the eastern TP. The internal and external cycle of the water cycle can stimulate (suppress) each other through PRE over the western (eastern) TP. This mechanism linked the changes in the PRE recycling and atmospheric circulation, and induced the increasing trend over TP in summer.

Dust aerosol can affect the atmospheric thermal structure and exert great melting potential on snow and ice sheets. In this study, the decadal climatology of dust‐forced radiative heating (DRH) in the atmosphere over Tibetan Plateau and its surroundings (TPS) was investigated using the Santa Barbara DISORT Atmospheric Radiative Transfer (SBDART) model along with the CALIPSO satellite observations from 2007 to 2016. After screening out other aerosols, the vertical distribution of dust aerosol was examined to accurately assess the DRH. The net DRH showed a significant warm effect mainly by dust loading, which covers from the center of dust sources to their adjacent transport regions. The maximum value of the DRH appeared at the near‐surface, while the DRH decreased with an increase in height. The climatic average DRH at the near‐surface reached 16.8 K/month at the Taklimakan Desert (TD) and 10.8 K/month at the Gangetic Plain in spring, 13.7 K/month at the Indus Plain in summer, which is 3–3.6 times warmer than the column‐averaged DRHs. This study also found the most significant influence of dust events on the Qaidam Basin in the TPS, in which the near‐surface DRH was 4.7 K/month during spring. It is also noteworthy that the intermonth and interannual variations of the DRH highlighted the significant warming effect of dust aerosols on the atmospheric thermal structure, especially at the near‐surface. In addition, we need to pay more attention to changes in snow‐related processes influenced by absorbing aerosols and the light‐absorbing impurities deposited in snow over the TPS.

Aerosols are important environmental factors that can influence deep convective clouds (DCCs) by serving as cloud condensation nuclei. Due to complications in DCC dynamics and microphysics, and aerosol size distribution and composition, understanding aerosol‐DCC interactions has been a daunting challenge. Recently, the convective invigoration mechanisms through enhancing latent heating in condensation and ice‐related processes that have been proposed in literature are debated for their significance qualitatively and quantitatively. A salient issue arising from these debates is the imperative need to clarify essential knowledge and methodologies in investigating aerosol impacts on deep convection. Here we have presented our view of key aspects on investigating and understanding these invigoration mechanisms as well as the aerosol and meteorological conditions under which these mechanisms may be significant based on new findings. For example, the condensational invigoration is most significant under a clean condition with an introduction of a large number of ultrafine particles, and the freezing‐induced invigoration can be significant in a clean condition with a large number of relatively large‐size particles being added. We have made practical recommendations on approaches for investigating aerosol impacts on convection with both modeling and observations. We note that the feedback induced by the invigoration via the enhanced latent heating to circulation and meteorology can be an important part of aerosol impacts but is very complicated and varies with different convective storm types. This is an important future direction for studying aerosol‐DCC interactions.

Using almost 10 years of observations of clouds and aerosols from the US Southern Great Plains (SGP) atmospheric observatory and the Semi-Arid Climate and Environment Observatory of Lanzhou University (SACOL) in China, the impact of aerosols on single-layer overcast clouds over continental land for different regimes were investigated. Atmospheric conditions at the two sites were first compared in an attempt to isolate the influence of aerosols on cloud properties from dynamic and thermodynamic influences. Cloud types and amounts are similar at the two sites. The dominant aerosol types at the SGP and SACOL sites are sulphate and dust, respectively, with greater aerosol optical depths (AODs) and absorption at the SACOL site. Aerosol first indirect effect (FIE) ranges from 0.021 to 0.152 and from −0.078 to 0.047 at the SGP and SACOL sites, respectively, when using the AOD below cloud base as CCN proxy. Although differences exist, the influence of meteorological conditions on the FIE at the two sites is consistent. FIEs are easily detected under descending motion and dry condition. The FIE at the SGP site is larger than that at the SACOL site, which suggests that the cloud albedo effect is more sensitive under relatively cleaner atmospheric conditions and the dominating aerosol at the SACOL site has less hygroscopicity. The radiative forcing of the FIE over the SGP site is −3.2 W m⁻² for each 0.05 increment in FIE. Cloud durations generally prolong as aerosol loading increases, which is consistent with the hypothesis of the aerosol second indirect effect. The negative relationship between cloud duration time and aerosol loading when aerosol loading reaches a large value further might suggest a semidirect effect.

Air quality is predominantly influenced by two factors: emission sources and meteorological conditions. Understanding their relative contribution is essential for developing effective air pollution control strategies. Two rounds of lockdown measures in Lanzhou during the winter of 2021 and 2022 offered a valuable opportunity to reveal the impact of pollutant emissions and meteorological conditions on air pollution events. The reduction in emissions during the pandemic lockdown period (2021–2022) resulted in a 36.05% decrease in PM_2.5 concentrations compared to the historical period of 2014–2020. Using ERA5 reanalysis meteorological data and principal component analysis, weather patterns were classified into three distinct types: favorable for pollutant accumulation (FPA), unfavorable for pollutant accumulation (NFP), and neutral condition (NTL). A comparative analysis of pollutant concentrations, frequency, and duration of each weather type during the lockdown and historical periods revealed that weather types had a minimal impact on pollutant levels, with emissions serving as the dominant factor. Nevertheless, the occurrence of FPA was often linked to severe pollution events, suggesting a positive feedback loop between severe pollution and FPA weather type. This indicated that FPA can lead to severe pollution events and more severe pollution may be associated with prolonged FPA durations. These findings suggest that identifying FPA weather patterns can significantly inform the implementation of air pollution control measures to mitigate air pollution levels.