Potential impacts of future reduced aerosols on internal dynamics characteristics of precipitation based on model simulations over southern China

In this study, the scaling behaviors of precipitation records over southern China are investigated by using the detrended fluctuation analysis (DFA) method. It is found that the precipitation records over southern China exhibit relatively weak long-term correlation characteristics. The scaling exponents in coastal areas are close to 0.6 showing long-term correlation while in inland areas, uncorrelation can be found with the scaling exponents close to 0.5. Based on the long-term correlation characteristics of the observed precipitation records, the performance of the Community Earth System Model (CESM1) in simulating precipitation over southern China is evaluated and the results show that the CESM1 can simulate the internal dynamics characteristics of precipitation series in southern China. As indicated by the DFA results of simulated precipitation data from CESM1, the long-term correlation of precipitation records during the late-21st century (2071–2100) will increase in the Huai river basin under the RCP8.5 simulation scenario in summer and decrease in most regions of southern China under both the RCP8.5 and RCP8.5_FixA scenarios in comparison with the present condition (1987–2016). Additionally, the differences of precipitation scaling exponents between the RCP8.5 and RCP8.5_FixA simulation scenarios further indicate that the future reduced aerosols emissions will contribute to strengthening the long-term correlation of precipitation records in the Huai river basin in summer. Compared to present condition, the precipitation scaling exponents will increase by more than 0.1 during the late-21st century.