A verification framework for South American sub-seasonal precipitation predictions
A verification framework for South American sub-seasonal precipitation predictions
复制标题
南美次季节降水预测验证框架
DOI：
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发表时间：
2018
影响因子：
1.2
通讯作者：
F. Andrade
中科院分区：
文献类型：
--
作者：
C. A. Coelho;M. A. Firpo;F. Andrade
本文提出了一个验证框架，南美亚季节（周累计）降水预测提前一至四周。该框架评估后报和近真实的时间预测质量，侧重于选择的属性（关联，准确性，歧视，可靠性和分辨率）。这些属性使用确定性和概率性得分进行测量。这种基于属性的框架允许根据次季节后报和接近真实的时间预报样本的可用性在三个级别上产生核查信息。该框架是有用的，通过帮助预报员确定模型预测的优点和不足，以及在哪里可以信任的模型指导信息，以支持未来的例行次季节预测实践。根据检验抽样策略定义了三个信息层次，分别为目标周后报检验、全季后报检验、全季近真实的时预报检验。该框架使用ECMWF亚季节降水预测说明。对于调查期间（秋季），合理的一致性之间的后报和近真实的时间预报质量在三个层次。提前1 ~ 2周制作的次季节降水预报比提前3 ~ 4周制作的次季节降水预报效果更好。巴西东北部地区呈现出良好的亚季节降水预测性能，特别是在关联性，准确性和歧视属性。该地区被认为是南美洲最有可能提前一至四周进行亚季节降水预测的地区。当对南美洲大陆的所有预测进行汇总时，概率评估显示出适度的区分能力，预测显然需要校准以提高可靠性，并可能与其他模型产生的预测相结合以提高分辨率。建议的框架也是有用的，为模型开发人员提供反馈，以确定未来的亚季节预测系统的改进的优点和缺点。
This paper proposes a verification framework for South American sub-seasonal (weekly accumulated) precipitation predictions produced one to four weeks in advance. The framework assesses both hindcast and near real time forecast quality focusing on a selection of attributes (association, accuracy, discrimination, reliability and resolution). These attributes are measured using deterministic and probabilistic scores. Such an attribute-based framework allows the production of verification information in three levels according to the availability of sub-seasonal hindcasts and near real time forecasts samples. The framework is useful for supporting future routine sub-seasonal prediction practice by helping forecasters to identify model forecast merits and deficiencies and regions where to trust the model guidance information. The three information levels are defined according to the verification sampling strategy and are referred to as target week hindcast verification, all season hindcast verification, all season near real time forecast verification. The framework is illustrated using ECMWF sub-seasonal precipitation predictions. For the investigated period (austral autumn), reasonable accordance was identified between hindcasts and near real time forecast quality across the three levels. Sub-seasonal precipitation predictions produced one to two weeks in advance presented better performance than those produced three to four weeks in advance. The northeast region of Brazil presented favorable sub-seasonal precipitation prediction performance, particularly in terms of association, accuracy and discrimination attributes. This region was identified as a region where sub-seasonal precipitation predictions produced one to four weeks in advance are most likely to be successful in South America. When aggregating all predictions over the South American continent the probabilistic assessment showed modest discrimination ability, with predictions clearly requiring calibration for improving reliability and possibly combination with predictions produced by other models for improving resolution. The proposed framework is also useful for providing feedback to model developers in identifying strengths and weaknesses for future sub-seasonal predictions systems improvements.