Are regional climate models relevant for crop yield prediction in West Africa?
Are regional climate models relevant for crop yield prediction in West Africa?
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区域气候模型与西非作物产量预测相关吗？
DOI：
10.1088/1748-9326/6/1/014008
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发表时间：
2011
影响因子：
6.7
通讯作者：
M. Vrac
中科院分区：
文献类型：
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作者：
Pascal Oettli;B. Sultan;C. Baron;M. Vrac
这项研究评估了最先进的区域气候模型在西非农业应用中的准确性。评估了一组九个区域配置和八个区域模式，这些模式来自合奏项目。虽然它们都是基于相似的大范围条件，但区域模型在再现作物生产最关键变量方面的表现是非常不同的。因此，当在气候/作物模拟系统中使用区域模型时，这导致在作物产量预测中存在很大的离散性。这种色散来自于每个区域模式中不同的物理特性，以及对单个区域模式的参数选择。事实上，同一区域模式的两种配置有时比两种不同的区域模式更不同。将偏差校正技术应用于气候模式输出，取得了良好的效果。经过偏差修正的气候变量模拟的产量显示出更接近实际的平均值和标准差。然而，这种偏差校正技术不能改善模拟产量的年际变化的重现性。这项研究证实了多模型方法在量化影响研究不确定性方面的重要性，并强调了结合区域和统计缩小尺度技术的好处。最后，报告指出，迫切需要解决控制季风系统的大气过程中的主要不确定因素，并促进在这方面评价和改进气候和天气预报模型。
This study assesses the accuracy of state-of-the-art regional climate models for agriculture applications in West Africa. A set of nine regional configurations with eight regional models from the ENSEMBLES project is evaluated. Although they are all based on similar large-scale conditions, the performances of regional models in reproducing the most crucial variables for crop production are extremely variable. This therefore leads to a large dispersion in crop yield prediction when using regional models in a climate/crop modelling system. This dispersion comes from the different physics in each regional model and also the choice of parametrizations for a single regional model. Indeed, two configurations of the same regional model are sometimes more distinct than two different regional models. Promising results are obtained when applying a bias correction technique to climate model outputs. Simulated yields with bias corrected climate variables show much more realistic means and standard deviations. However, such a bias correction technique is not able to improve the reproduction of the year-to-year variations of simulated yields. This study confirms the importance of the multi-model approach for quantifying uncertainties for impact studies and also stresses the benefits of combining both regional and statistical downscaling techniques. Finally, it indicates the urgent need to address the main uncertainties in atmospheric processes controlling the monsoon system and to contribute to the evaluation and improvement of climate and weather forecasting models in that respect.