Despite the importance of precipitation and moisture transport over the Tibetan Plateau for glacier mass balance, river runoff and local ecology, changes in these quantities remain highly uncertain and poorly understood. Here we use observational data and model simulations to explore the close relationship between summer rainfall variability over the southwestern Tibetan Plateau (SWTP) and that over central-eastern India (CEI), which exists despite the separation of these two regions by the Himalayas. We show that this relationship is maintained primarily by ‘up-and-over’ moisture transport, in which hydrometeors and moisture are lifted by convective storms over CEI and the Himalayan foothills and then swept over the SWTP by the mid-tropospheric circulation, rather than by upslope flow over the Himalayas. Sensitivity simulations confirm the importance of up-and-over transport at event scales, and an objective storm classification indicates that this pathway accounts for approximately half of total summer rainfall over the SWTP.

A team effort to develop a Community Integrated Earth System Model (CIESM) was initiated in China in 2012. The model was based on NCAR Community Earth System Model (Version 1.2.1) with several novel developments and modifications aimed to overcome some persistent systematic biases, such as the double Intertropical Convergence Zone problem and underestimated marine boundary layer clouds. Aerosols' direct and indirect effects are prescribed using the MACv2‐SP approach and data sets. The spin‐up of a 500‐year preindustrial simulation and three historical simulations are described and evaluated. Prominent improvements include alleviated double Intertropical Convergence Zone problem, increased marine boundary layer clouds, and better El Niño Southern Oscillation amplitude and periods. One deficiency of the model is the significantly underestimated Arctic and Antarctic sea ice in warm seasons. The historical warming is about 0.55 °C greater than observations toward 2014. CIESM has an equilibrium climate sensitivity of 5.67 K, mainly resulted from increased positive shortwave cloud feedback. Our efforts on porting and redesigning CIESM for the heterogeneous Sunway TaihuLight supercomputer are also introduced, including some ongoing developments toward a future version of the model.

A Lagrangian approach is applied to explore the evaporative moisture sources within the boundary layer for 103 wintertime extreme precipitation events over South China during 1979–2013. Oceanic sources provided about 67.7% of the moisture for these extreme precipitation events, with terrestrial sources providing the remaining parts. The five most important moisture source regions were the South China Sea (30.9% of the total moisture source within boundary layer), the western North Pacific (20.2%), the East China Sea (14.9%), South China (i.e., moisture recycling, in which local evapotranspiration supplies moisture for precipitation; 14.6%), and southeastern Asia (11.5%). Characteristic trajectories linking moisture from the key source regions to South China are identified. All of these trajectories entered China south of the Yangtze River, with characteristic time scales ranging from 2.8 to 5.7 days. The critical circulation patterns for moisture transport from different source regions are also determined. Cyclonic anomalies over South China and its surrounding continental areas favored moisture transport from the South China Sea and southeastern Asia. To leading order, changes in the relative contributions of these and other key moisture source regions were associated with changes in the location or development pattern of these cyclonic anomalies. Beyond these relationships, the presence of anticyclonic anomalies over the western North Pacific favored moisture transport from the western North Pacific, while the absence of these anomalies favored moisture recycling within South China and moisture transport from the East China Sea.

A novel full‐field initialization strategy based on the dimension‐reduced projection four‐dimensional variational data assimilation (DRP‐4DVar) is proposed to alleviate the well‐known initial shock occurring in the early years of decadal predictions. It generates consistent initial conditions, which best fit the monthly mean oceanic analysis data along the coupled model trajectory in 1 month windows. Three indices to measure the initial shock intensity are also proposed. Results indicate that this method does reduce the initial shock in decadal predictions by Flexible Global Ocean‐Atmosphere‐Land System model, Grid‐point version 2 (FGOALS‐g2) compared with the three‐dimensional variational data assimilation‐based nudging full‐field initialization for the same model and is comparable to or even better than the different initialization strategies for other fifth phase of the Coupled Model Intercomparison Project (CMIP5) models. Better hindcasts of global mean surface air temperature anomalies can be obtained than in other FGOALS‐g2 experiments. Due to the good model response to external forcing and the reduction of initial shock, higher decadal prediction skill is achieved than in other CMIP5 models.