Seasonal percentage (%) change in rainfall from the median projected for 2036-2065, relative to present (1976 - 2005), for JJA season under the RCP 8.5 pathway

Seasonal percentage (%) change in rainfall from the median projected for 2036-2065, relative to present (1976 - 2005), for JJA season 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.

本数据集展示南部非洲区域在典型浓度路径（Representative Concentration Pathway, RCP）8.5情景下，JJA季节的降雨量相较于1976-2005年基准期，2036-2065年预估中值的季节性百分比（%）变化。为生成该图像，研究采用罗斯比中心区域模式（Rossby Centre regional model, RCA4）作为侧边界强迫场，将9个粗分辨率全球环流模式（General Circulation Models, GCM）降尺度至0.44°×0.44°的更高空间分辨率。该模式模拟的日降雨量平均值被用于生成季节性变化的预估结果。本次预估采用高排放情景（RCP8.5），该情景预估至2100年大气二氧化碳浓度将达到约950ppm。研究计算了相关的均方根误差（Root Mean Square Deviation, RMSD），其结果可展示模式模拟残差预估结果的不确定性范围，并能相对呈现预估不确定性高低各异的空间区域分布特征。