Root Mean Square Difference between the nine ensemble member change anomalies of the seasonal total rainfall for the 10% percentile for 2036 - 2065 relative to 1976-2005, for the SON season, under the RCP 8.5 pathway

Root Mean Square Difference for seasonal (SON) rainfall (mm per month) change from the 10% percentile projected for 2036-2065, relative to present (1976 - 2005), under the RCP 8.5 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 high (RCP8.5) pathway which associates CO2 concentrations of approximately 950ppm 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.

针对南部非洲区域，在典型浓度路径8.5（RCP 8.5）情景下，以1976-2005年为基准期，2036-2065年投影得到的SON时段季节降水（单位：毫米/月）变化的10%分位点对应的均方根差（Root Mean Square Difference）。为生成该图像，共选取9台粗分辨率全球环流模式（General Circulation Models, GCM），通过侧边界强迫的罗斯比中心区域模式（RCA4）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投影结果。本次投影采用的高排放情景（RCP8.5）预计到2100年时，大气二氧化碳浓度将达到约950ppm。研究计算得到的对应均方根差（RMSD），可展示模式模拟投影残差的不确定性范围，并相对直观地呈现出投影不确定性高低各异的空间区域分布。