This paper documents version 1 of the Finite‐volume Atmospheric Model of the IAP/LASG (FAMIL1), which has a flexible horizontal resolution up to a quarter of 1°. The model, currently running on the “Tianhe 1A” supercomputer, is the atmospheric component of the third‐generation Flexible Global Ocean‐Atmosphere‐Land climate System model (FGOALS3) which will participate in the Coupled Model Intercomparison Project Phase 6 (CMIP6). In addition to describing the dynamical core and physical parameterizations of FAMIL1, this paper describes the simulated characteristics of energy and water balances and compares them with observational/reanalysis data. The comparisons indicate that the model simulates well the seasonal and geographical distributions of radiative fluxes at the top of the atmosphere and at the surface, as well as the surface latent and sensible heat fluxes. A major weakness in the energy balance is identified in the regions where extensive and persistent marine stratocumulus is present. Analysis of the global water balance also indicates realistic seasonal and geographical distributions with the global annual mean of evaporation minus precipitation being approximately 10⁻⁵ mm d⁻¹. We also examine the connections between the global energy and water balance and discuss the possible link between the two within the context of the findings from the reanalysis data. Finally, the model biases as well as possible solutions are discussed.

The East Asian summer monsoon precipitation has exhibited a well-known “southern China flood and northern China drought” pattern in recent decades. The increase in aerosols and warming oceans are recognized as two important forcings that control of the precipitation trends over East Asian land. However, in this study, by using large ensemble simulations from the CMIP6 Polar Amplification Model Intercomparison Project (PAMIP), the influence of Arctic amplification, serving as the prominent feature of global warming, is very important in modulating the East Asian summer precipitation pattern, which is comparable to the influence of sea surface temperature (SST). Additionally, the observed “southern China flood and northern China drought” pattern only exists in July and August, whereas a triple pattern with the precipitation positive anomaly center over Middle China occurs in June. These patterns are closely connected with the regional differences in Arctic sea ice loss from June to July, affected through both the Rossby waves propagating in a weaker westerly jet and the decrease in the large-scale meridional thermal contrast in a warming climate.