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In this paper, we evaluate a 48‐member multiphysics ensemble using the Weather Research and Forecasting (WRF) model for the JJA extreme precipitation and temperature in 2003 over the CORDEX‐EA‐II domain. The simulated precipitation and temperature are reasonable in the subregions controlled by a large‐scale circulation, yet the biases for both precipitation and temperature are evident over the subregions where the effects of mesoscale processes are important. The performance of various combinations of WRF physical schemes for simulating the JJA precipitation is dependent on the region. Meanwhile, the cumulus and microphysical schemes have substantial influences on the simulation of precipitation, and the land surface models and cumulus schemes play crucial roles in the surface temperature. Our analysis shows that the combination of Noah for the land surface process, Lin for the microphysics, G3D for the cumulus parameterization, and CAM for the radiation scheme can provide the most reliable reproduction of both precipitation and temperature extremes over China. Ensemble analysis shows that the simulated climate extremes are usually accompanied by a large ensemble spread, implying sensitivities to the model physical processes in some subregions. The simulated wind fields at low‐to‐middle atmospheric levels display responses to the options of the land surface models and cumulus schemes. The essential impact of the land–atmospheric interaction on simulating the extremes can be largely attributed to the active convective processes. WRF has difficulties in reproducing the observed temporal evolution of the rainfall process, which consists of continuous large rainfall episodes in the observation data set during the simulation period. [ABSTRACT FROM AUTHOR]

precipitation and evaporation are two vital components of water cycle, and Hydrogen and oxygen stable isotopes are important tracers in water, which are very sensitive to changes in the climate and the water cycle. Rayleigh Fractionation equation is usually applied to calculate isotope distributions in order to quantify the precipitation and evaporation processes. It is reasonable to explain the evaporation process using the Rayleigh fractionation equation. However, the composition of hydrogen and oxygen stable isotopes in the precipitation will change due to the effects of dynamic fractionation and dilution during raindrop fall. In this case, it is not feasible to rely entirely on the Rayleigh fractionation equation. In this paper, atmospheric precipitation isotopes data recorded during 1996–2016 in Hong Kong from the Global Network of Isotopes in Precipitation (GNIP) are analyzed, including local meteoric water line (LMWL), deuterium-excess (d), temperature effect and rainfall amount effect. The results indicate that precipitation is affected by secondary evaporation and dilution effects. In addition, the stable isotope composition in precipitation is the result of temperature and precipitation. Due to the effects of these two effects, changes of isotope composition in precipitation are not always consistent. When the rainfall density is very large, the temperature effect is covered up and the temperature is inversely related to the isotope composition of precipitation. In contrast, when the rainfall density is small, the temperature is positively related to the isotope composition of precipitation. Therefore, it is suggested to consider the rainfall density while studying the relationship between the isotope composition of precipitation and the local climate. These finds can provide some enlightenments and references on how to investigate the changing pattern of isotope composition in precipitation. [ABSTRACT FROM AUTHOR]

In a changing climate, there is an interest in predicting how extreme rainfall events may change. Using historical records, several recent papers have evaluated whether high-intensity precipitation scales with temperature in accordance with the Clausius--Clapeyron (C--C) relationship. For varying locations in Europe, these papers have identified both super C--C relationships as well as a breakdown of the C--C relationship under dry conditions. In this paper, a similar analysis is carried out for the United States using data from 14 weather stations clustered in four different hydroclimatic regions: the coastal northeast, interior New York, the central plains, and the western plains. In all regions except interior New York state, 99th percentile 1-h precipitation generally followed the C--C relation. In interior New York, there was evidence that intensity scaled with a super C--C relationship. For the 99.9th percentile precipitation, interior New York displayed some moderate evidence of a super C--C relationship, the western plains showed little relation between precipitation and temperature, and the remainder of sites generally scaled with the C--C relationship. Also, if only July, August, and September precipitation is considered, all stations except those in interior New York have little relation between temperature and precipitation, suggesting that precipitation intensity during summer months may not be well constrained by the C--C relationship. Overall, the C--C relationship (or a variation thereof) does not appear to constrain extreme precipitation in all regions and in all seasons, and its ability to aid in constraining future predictions of extreme precipitation may only be relevant to certain locales and time periods. [ABSTRACT FROM AUTHOR]