Bias Correction of Paleoclimatic Reconstructions: A New Look at 1,200+Years of Upper Colorado River Flow
Bias Correction of Paleoclimatic Reconstructions: A New Look at 1,200+Years of Upper Colorado River Flow
复制标题
DOI：
10.1029/2019gl086689
复制
发表时间：
2020-01-16
影响因子：
5.2
通讯作者：
Ficklin, Darren L.
中科院分区：
文献类型：
--
作者：
Robeson, Scott M.;Maxwell, Justin T.;Ficklin, Darren L.
偏差校正，而广泛使用的气候模式输出，通常不适用于古气候重建。虽然许多重建模型具有较低的平均误差，但它们仍然可能包含偏差，特别是在分布的尾部。如果谨慎使用，偏差修正可能是一个有价值的程序，可以改变对过去事件的解释。通过对上科罗拉多河径流的标志性树轮重建分析，发现其概率分布与实测径流的概率分布有明显不同。使用分位数映射偏差校正重建，我们分析了完整的重建记录，特别是两个事件：1100年代megadbrought和1600年代初的洪积。总的来说，偏差修正使得1100年代的巨型地震，也就是1,200多年来最大的记录，变得更加极端。经过偏差校正后，17世纪初的暴雨在量级上略超过20世纪初的世纪暴雨，但在持续时间上没有超过。总的来说，当古气候重建直接与观测结果进行比较时，应考虑偏差校正。
Bias correction, while widely used with climate-model output, is not typically applied to paleoclimatic reconstructions. While many reconstruction models have low average error, they still may contain bias, especially in the tails of distributions. Bias correction, used cautiously, can be a valuable procedure that alters interpretations of past events. Analyzing the iconic tree-ring reconstruction of Upper Colorado River flow, we find that its probability distribution is markedly different from that of observed flow. Using quantile mapping to bias correct the reconstruction, we analyze the full reconstructed record and two events in particular: the 1100s megadrought and the early 1600s pluvial. Overall, bias correction made the 1100s megadrought, the largest in the 1,200+year record, even more extreme. After bias correction, the early 1600s pluvial marginally exceeds the early twentieth century pluvial in magnitude but not in duration. Overall, bias correction should be considered whenever paleoclimatic reconstructions are compared directly to observations.