Guangtao Dong

and 4 more

Realistic representation of detailed rainfall characteristics on local scale by current state-of-the-art climate models remains a key challenge, especially on sub-daily timescales. In this research, the convection-permitting Weather Research and Forecasting (WRF) model configured with 1.5 km grid spacing is used to simulate precipitation on sub-daily timescales over the Yangtze River Delta Region of China for continuous 10 years (2005–2014). The simulations are compared to rain gauge observations, reanalysis data, and the simulations of a lower resolution WRF with 9 km grid spacing that has a parameterization of convection. The results show that precipitation over the region can be well captured by using the convection-permitting model (CPM). Furthermore, the intensity, duration and coverage of these precipitation events can be more accurately described by the CPM. On the convection timescales of 1–4 hours, especially for heavy rainfall events, the CPM is more accurate than the convection-parameterized model in capturing the short-duration events, which may be related to its better account of physical processes related with the convection on the convection-permitting scale. In addition, the extreme events which are more localized and with short-duration can be represented better by the CPM while the convection-parameterized model tends to produce widespread precipitation events covering more grid cells than observed. Biases of the simulation by the 9-km mesh convection-parameterized mode appear to be related to the deficiencies in the representation of convections.

Dongli Fan

and 4 more

The arid and semi-arid regions are highly vulnerable to climate change and variability. Agricultural production in these regions is particularly vulnerable because of its heavy dependence on on climate conditions. Therefore, it is important to improve the projections of future agro-climatic conditions. This study investigates the projections of agroclimatology change during 2031–2050 under the Representative Concentration Pathway (RCP) 8.5 emission scenario in the semi-arid North China. It is simulated by the agro-ecological zone (AEZ) model with climate data provided by the regional climate model (RCM) of Providing regional Climates for Impacts Studies (PRECIS). The Chinese Medicinal Yam (CMY), which is genuinely produced over semi-arid regions, is taken as an example to study the change of its yield and producing area under future climate change. The results show that the high-resolution RCM simulation corresponds better with the observations than the general circulation model (GCM) in precipitation and temperature. In North China, the CMY genuine production area, the precipitation will increase by about 10% and the temperature will increase by about 2oC under the RCP8.5 scenario. After the evaluation and projection of climate models, the potential yield of CMY and the suitable planting regions are simulated by using the AEZ model. The CMY production areas will expand northward in the future, due to the climate warming in the north. The traditional yam production area still maintains the suitability of CMY production. The production of CMY will augment because of the increased production area.