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 8.5 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 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 temperature 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.本数据集为南部非洲区域在典型浓度路径8.5（Representative Concentration Pathway 8.5，RCP 8.5）情景下，以1976-2005年为基准时段，2066-2095年季节（SON，即9月、10月、11月）平均近地面（2米）温度变化相较于10%分位数投影的均方根差（Root Mean Square Difference，RMSD）。为生成对应可视化图像，研究团队使用罗斯比中心区域气候模式（Rossby Centre regional model, RCA4）作为侧向边界强迫场，将9个粗分辨率全球环流模式（General Circulation Models, GCM）的输出结果降尺度至0.44°×0.44°的更高空间分辨率。该模式模拟得到的逐日平均温度数据，被用于生成季节温度变化的投影结果。本次投影采用高排放情景RCP8.5，该情景预计至2100年大气二氧化碳浓度将达到约950ppm。本研究计算得到的均方根差（RMSD）可反映投影模型模拟残差的不确定性范围，并可直观呈现空间区域间投影不确定性的相对高低分布差异。