The northeast monsoon (October–December; NEM) rainfall is a very important entity to about 250 million people residing in the South Peninsular India (SPI) region as it is their principle rainy season and contributes mostly to their annual rainfall. The aim of the study is to obtain the future projections of NEM rainfall over this region representing three different greenhouse gas emission scenarios (i.e., RCP 2.6, RCP 4.5 and RCP 8.5) for two future time slices, i.e., near (2020–2049) and far future (2070–2099) estimated from a set of high-resolution regional climate simulations performed under CORDEX-SA experiments. To achieve that, first, an assessment of ten CORDEX-SA regional climate model (RCM) simulations is done for NEM rainfall over SPI for present climate (1976–2005) against India Meteorological Department high resolution (0.25º × 0.25º) gridded rainfall analysis dataset. Then, the change in NEM rainfall over SPI in the near and far future is computed after applying standardized reconstruction technique to adjust the bias present in the models. The results suggest that most of the CORDEX-SA experiments are able to simulate the spatial distribution of NEM seasonal rainfall and its variability over SPI but there is an inability in capturing realistic magnitudes and the errors are more over the east and west coast where most of the rainfall occurs. The experiment with RCA4 driven by EC-EARTH global model and REMO2009 driven by MPI-ESM has a fairly lesser bias than the other models, whereas the bias is more in LMDZ-IITM-RegCM4. The experiments by CCAM models have very similar characteristics in representing the rainfall pattern. The standardized reconstruction bias correction technique was found to significantly improve the performance of the climate models in representing the climatological mean and inter-annual variability of (IAV) of NEM rainfall over SPI, but in case of categorical rainfall years, improvement is seen only in the normal rainfall years. In the future, for RCP 2.6, there is a rise in NEM rainfall in the first half of the twenty-first century, which is projected to decline after that; however, in the other two scenarios, the rainfall is projected to increase. It is also found that there may be lesser excess rainfall years and more deficit rainfall years in the RCP 4.5 and 8.5 scenarios in the near future, and no deficit rainfall years are projected in the far future in both these scenarios based on the present climate. It is also noticed that the variability in the NEM rainfall over this region may remarkably increase in all the three future scenarios, which will highly impact various water resources management sectors. Thus, this study is very useful in determining the effects on various sectors due to the variability in NEM rainfall over this region and for adapting to climate change using advanced technologies for a sustainable future.

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CORDEX-南亚模拟的性能评估和印度南部半岛东北季风降雨的未来预测

东北季风（10 月至 12 月；NEM）降雨对居住在南印度半岛 (SPI) 地区的约 2.5 亿人来说是一个非常重要的实体，因为这是他们的主要雨季，并且对他们的年降雨量贡献最大。该研究的目的是获得代表三个不同温室气体排放情景（即 RCP 2.6、RCP 4.5 和 RCP 8.5）的该地区 NEM 降雨的未来预测，用于两个未来时间片，即接近（2020-2049）从 CORDEX-SA 实验下进行的一组高分辨率区域气候模拟估计的远未来（2070-2099）。为了实现这一目标，首先，针对印度气象部门的高分辨率 (0.25º × 0.0.25º × 0.25º)，针对当前气候 (1976-2005) SPI 上的 NEM 降雨对十个 CORDEX-SA 区域气候模型 (RCM) 模拟进行了评估。25º) 网格降雨分析数据集。然后，在应用标准化重建技术调整模型中存在的偏差后，计算近期和远未来 NEM 降雨量在 SPI 上的变化。结果表明，大多数 CORDEX-SA 实验能够模拟 NEM 季节性降雨的空间分布及其在 SPI 上的变异性，但无法捕捉到真实的震级，并且错误更多地发生在东海岸和西海岸，其中大部分地区降雨发生。EC-EARTH 全局模型驱动的 RCA4 和 MPI-ESM 驱动的 REMO2009 的实验比其他模型的偏差要小得多，而 LMDZ-IITM-RegCM4 的偏差更大。CCAM 模型的实验在表示降雨模式方面具有非常相似的特征。发现标准化重建偏差校正技术可显着提高气候模型在表示 SPI 上 NEM 降雨的气候平均值和年际变率 (IAV) 方面的性能，但在分类降雨年的情况下，改进仅在正常降雨年。未来，对于RCP 2.6，21世纪上半叶NEM降雨量增加，预计此后下降；然而，在其他两种情况下，降雨量预计会增加。还发现，在近期的RCP 4.5和8.5情景中，可能存在较少的过量降雨年和更多的缺雨年，并且在这两种情景中基于当前气候预测在远未来都没有缺雨年。还注意到，该地区的 NEM 降雨量在所有三种未来情景中都可能显着增加，这将对各个水资源管理部门产生重大影响。因此，这项研究对于确定由于该地区 NEM 降雨量的变化而对各个部门的影响以及使用先进技术适应气候变化以实现可持续未来非常有用。