Sensitivity of summer precipitation in regional spectral model simulations over eastern China to physical schemes: Daily, extreme and diurnal cycle

Abstract

In this study, the capability of the National Centers for Environmental Prediction (NCEP) Regional Spectral Model (RSM) in reproducing the precipitation in eastern China is evaluated with the simulation of 25-year (1983-2007) summertime climate driven by the NCEP-Department of Energy reanalysis. The impacts of different physical schemes on daily precipitation, diurnal cycle and precipitation extremes are studied through detailed analyses. The results show that the RSM model can reproduce the precipitation characteristics over eastern China, and the results are sensitive to the internal model physics and spectral nudging method. The cloud water prediction scheme of CLD3 (CLD n , the cloud schemes, classified according to the complexity microphysical processes) and the modified version of the Kain-Fritsch scheme (KF2) tend to overestimate the summer precipitation by reproducing higher humidity, while the CLD1 and the Relaxed Arakawa Schubert scheme (RAS) always underestimate it. It is also demonstrated that RSM has the capability to reproduce the spatial distributions of the extreme precipitation intensity and duration. The physical schemes have great impact on the simulations of extreme precipitation over eastern China, especially on regional scales. For the diurnal cycle of precipitation, the responses of the simulated amplitude to the physical schemes differ with regions.The RAS scheme underestimates the amplitudes over southeastern China, while the KF2 generates positive biases. The involving of the scale selective bias correction (SSBC) method can properly improve the simulated mean precipitation and diurnal cycle of summer precipitation. However, it shows lower skill in improving extreme precipitation indices over eastern China, especially in the experiments with CLD3 scheme. In summary, the selection of CLD1 and KF2 scheme, involving SSBC method performs better than the other experiments. K E Y W O R D Seastern China, model sensitivity, physical schemes, regional spectral model, summer precipitation

Prediction of the Diurnal Variation of Summertime Precipitation Over the Sichuan Basin by a Regional Model

“…To understand the uncertainties of producing the diurnal variation of precipitation in the model, it is necessary to explore key mechanisms that drive the diurnal nature of precipitation from a physical perspective. Specifically, we will evaluate physical process discrepancies between observation and prediction linked to the diurnal variation of wind and atmospheric instability (Huang et al., 2013; Zong et al., 2019), which are important reasons for initiation of nocturnal precipitation over the SCB based on the research of Li, Jiang, and Heng (2021) and Li, Li, et al. (2021).…”

Sensitivity of Simulations of Extreme Mediterranean Storms to the Specification of Sea Surface Temperature: Comparison of Cases of a Tropical-Like Cyclone and Explosive Cyclogenesis

“…This method also reduces the tendency for model climate drift [28]. This approach together with the similarity in structure to the global model improves the consistency between the global reanalysis and the downscaled regional climate [25,26] While the RSM has been used for daily forecasting, most applications have focused on long-term, regional downscaling of the current climate for various regions around the world such as the southeastern United States [28], the monsoons of Indochina [29], West Africa [30], eastern China [31] and Brazil [32]. Many of the more recent studies have emphasized the RSM's success in simulating diurnal precipitation cycles as well as precipitation extremes [28][29][30][31].…”

“…As in the case of the TLC, here too we were interested in the sensitivity of explosive cyclogenesis to the warming trend observed in the SST of the Mediterranean [13] and the projected continued warming [31]. We therefore also ran a series of simulations with the MFS SST field increased by 1 • C increments up to a maximum increase of 5 • C, and for completeness we ran an additional set of simulations for comparable SST cooling scenarios.…”

Dynamical downscaling of inland and offshore near‐surface wind speed over China inCORDEXEast Asia Phase I andIIexperiments

“…Several CORDEX simulations with different physical schemes have been performed and evaluated over East Asia (Hui et al ., 2019; Yang et al ., 2019); thus, it is feasible to investigate the effects of physical schemes, such as the radiation parameterization and land surface schemes, on near‐surface wind simulation. In addition to physical processes, the lateral boundary condition (LBC), provided by global reanalysis data or global climate model (GCM) output, also has impact on regional climate simulation (Davies, 1976; Leung et al ., 2003; Zong et al ., 2019). The traditional treatment of LBC with the sponge layers does not ensure a perfect control in the large scale, particularly over large domains (Laprise et al ., 2012; Zong et al ., 2019).…”

“…In addition to physical processes, the lateral boundary condition (LBC), provided by global reanalysis data or global climate model (GCM) output, also has impact on regional climate simulation (Davies, 1976; Leung et al ., 2003; Zong et al ., 2019). The traditional treatment of LBC with the sponge layers does not ensure a perfect control in the large scale, particularly over large domains (Laprise et al ., 2012; Zong et al ., 2019). To make the model results consistent with the driving fields, spectral nudging (SN) method is introduced into RCMs (von Storch et al ., 2000; Tang et al ., 2017; 2018).…”