Root Mean Square Difference between the nine ensemble member change anomalies of the annual mean near-surface (2m) temperature for the median for 2066-2095 relative to 1976-2005, under the RCP 8.5 pathway

Root Mean Square Difference for annual mean near-surface (2m) temperature (°C) change from the median 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 annual 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.

本数据集表征南非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，2066-2095年的年平均近地表（2米）气温（℃）变化相较于其预估中值的均方根差（Root Mean Square Difference）。本图像的生成流程为：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）提供侧边界强迫，将其降尺度至0.44°×0.44°的更高空间分辨率。该模式模拟的逐日气温平均值被用于生成年际变化的气候预估结果。本次预估基于高排放情景RCP8.5路径生成，该情景预计到2100年二氧化碳浓度将达到约950ppm。所计算得到的对应均方根差可体现模式模拟预估残差的不确定性范围，并直观展现空间区域间预估不确定性的高低分布差异。