ENSO Normals: A New U.S. Climate Normals Product Conditioned by ENSO Phase and Intensity and Accounting for Secular Trends
ENSO Normals: A New U.S. Climate Normals Product Conditioned by ENSO Phase and Intensity and Accounting for Secular Trends
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DOI：
10.1175/jamc-d-18-0252.1
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发表时间：
2019-06
影响因子：
3
通讯作者：
A. Arguez;A. Inamdar;M. Palecki;C. Schreck;A. Young
中科院分区：
文献类型：
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作者：
A. Arguez;A. Inamdar;M. Palecki;C. Schreck;A. Young
气候正常值传统上每十年计算一次，作为一段时间（通常是30年）的平均值。这种方法假定气候是稳定的，最近引入了几种替代方法来解释单调的气候变化。然而，这些方法不能解释年际气候变率[例如，厄尔尼诺Niño-Southern涛动（ENSO）]，它系统地改变了气候的背景状态，类似于气候变化。这些影响及其不确定性是公认的，但它们没有反映在任何现成的气候常态数据集中。一套新的高分辨率标准是为美国周边地区导出的，它可以解释ENSO，并使用最佳气候标准(OCN) - 10年（15年）的温度（降水）运行平均值-来解释气候变化。通过减去运行均值计算异常，然后将其合成5个ENSO相位和强度类别：强La Niña、弱La Niña、中性、弱El Niño和强El Niño。季节性复合材料是为五个阶段中的每一个阶段生产的。ENSO法线是给定月份的这些组合与OCN的总和。结果是五组常态，每个阶段一组，用户可以就预期的ENSO结果进行咨询。虽然在大多数情况下发现了公认的ENSO模式，但弱El Niño事件出现了明显的东西温度异常模式。这种新产品可以帮助利益相关者规划气候变化中ENSO可能产生的广泛影响。
Climate normals are traditionally calculated every decade as the average values over a period of time, often 30 years. Such an approach assumes a stationary climate, with several alternatives recently introduced to account for monotonic climate change. However, these methods fail to account for interannual climate variability [e.g., El Niño–Southern Oscillation (ENSO)] that systematically alters the background state of the climate similar to climate change. These effects and their uncertainties are well established, but they are not reflected in any readily available climate normals datasets. A new high-resolution set of normals is derived for the contiguous United States that accounts for ENSO and uses the optimal climate normal (OCN)—a 10-yr (15 yr) running average for temperature (precipitation)—to account for climate change. Anomalies are calculated by subtracting the running means and then compositing into 5 ENSO phase and intensity categories: Strong La Niña, Weak La Niña, Neutral, Weak El Niño, and Strong El Niño. Seasonal composites are produced for each of the five phases. The ENSO normals are the sum of these composites with the OCN for a given month. The result is five sets of normals, one for each phase, which users may consult with respect to anticipated ENSO outcomes. While well-established ENSO patterns are found in most cases, a distinct east–west temperature anomaly pattern emerges for Weak El Niño events. This new product can assist stakeholders in planning for a broad array of possible ENSO impacts in a changing climate.