Root Mean Square Difference between the nine ensemble member change anomalies of the seasonal total rainfall for the 10% percentile for 2066-2095 relative to 1976-2005, for the DJF season, under the RCP 4.5 pathway

Root Mean Square Difference for seasonal (DJF) rainfall (mm per month) change from the 10% percentile projected for 2066-2095, relative to present (1976 - 2005), under the RCP 4.5 pathway for the southern African region. To generate the image, nine coarse General Circulation Models (GCM) are downscaled to a finer spatial resolution (0.44°x 0.44°) using the Rossby Centre regional model (RCA4) forcing its lateral boundaries. The model simulated daily rainfall averages, which are used to generate projections of seasonal change. The projections are generated using the medium to low (RCP4.5) pathway which associates CO2 concentrations of approximately 560ppm by the year 2100. The associated RMSD it calculated and shows the uncertainty range of the projected model simulated residual values, and gives a relative perspective of spatial areas associated with higher and lower projection uncertainties.本数据集表征南部非洲区域在典型浓度路径4.5（RCP 4.5）情景下，2066-2095年季节（12月-1月-2月，DJF）降水（单位：毫米/月）相较于当前基准期（1976-2005年）10%分位数的变化量的均方根差（Root Mean Square Difference）。为生成该可视化图像，研究采用罗斯比中心区域模式（RCA4）为9个粗分辨率全球环流模式（General Circulation Models，GCM）施加侧边界强迫，将其降尺度至0.44°×0.44°的更高空间分辨率。该模式模拟的日降水平均值被用于生成季节降水变化的预估结果。本次预估基于中低排放情景（RCP4.5），该情景预计至2100年大气二氧化碳浓度约为560ppm。本次计算得到的均方根差可展示模式模拟预估残差的不确定性范围，并直观呈现不同空间区域预估不确定性的高低差异。