Root Mean Square Difference between the nine ensemble member change anomalies of the seasonal mean near-surface (2m) temperature for the 10% percentile for 2066 - 2095 relative to 1976-2005, for the SON season, under the RCP 4.5 pathway

Root Mean Square Difference for seasonal (SON) mean near-surface (2m) temperature (°C) 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 temperature 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.

本数据集聚焦南部非洲区域在RCP4.5情景下，相对于1976-2005年当前基准气候，2066-2095年季节（SON，即9、10、11月）平均近地面（2米）气温（℃）变化的10%分位数对应的均方根差（Root Mean Square Difference）。为生成该可视化成果，研究采用罗斯比中心区域模式（Rossby Centre regional model, RCA4），通过强迫其侧边界条件，将9套粗分辨率全球环流模式（General Circulation Models, GCM）的模拟结果降尺度至0.44°×0.44°的更高空间分辨率。该模式输出的逐日气温平均值被用于构建季节尺度气温变化的预估结果。本次预估基于中低排放情景（RCP4.5），该情景预计到2100年大气CO₂浓度约为560ppm。本次计算得到的均方根差可表征模式模拟预估残差的不确定性范围，并能直观展现空间上不同区域预估不确定性的高低差异。