Uncertainty in climate projections for the 21st century northwest European shelf seas
Uncertainty in climate projections for the 21st century northwest European shelf seas
复制标题
21世纪西北欧陆架海气候预测的不确定性
DOI：
10.1016/j.pocean.2016.09.003
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发表时间：
2016
影响因子：
4.1
通讯作者：
R. Barciela
中科院分区：
文献类型：
--
作者：
J. Tinker;J. Lowe;A. Pardaens;J. Holt;R. Barciela
有许多不确定性来源会影响区域海洋的气候预测。我们评估了不确定的大规模气候强迫对欧洲西北部陆架海预测的影响。由扰动（大气）参数模型变体所做的全球大气-海洋气候模型（GCM）预测的集合，旨在跨越气候敏感性的不确定性，并使用陆架海模型 POLCOMS 动态缩小规模。模拟是在中等排放情景 (SRES A1B) 下作为瞬态实验（从 1952 年到 2098 年）进行的。本研究重点关注 2069 年至 2098 年相对于 1960 年至 1989 年的百年变化，但也参考了完整的瞬态模拟，以评估考虑到年际和低频变化的预测变化的重要性。 POLCOMS 预测的总体平均值显示，这些时期之间的陆架和年平均海面温度 (SST) 上升了 2.90 °C (±2σ= 0.82 °C)，海面盐度 (SSS) 清新了 -0.41 psu (±2σ= 0.47 psu)。我们使用与时间平均集合离散度（集合方差）和年际变率相关的方差来描述特定时期内字段的分布。对于当今时期的海表温度来说，集合方差和年际方差的大小在空间上都相当均匀。虽然未来的年际方差与当前的大小相似，但总体方差在未来一段时间内大幅增加。对于 SSS，两个方差来源在空间上都更加异质，并且在未来时期都会增加。我们研究了整个整体的预计陆架海变化与大规模气候强迫变化之间的关系。我们发现来自驱动 GCM 的近地表空气温度（整个域的平均值）和 POLCOMS 域以西的 GCM 表面盐度是陆架海内变化的良好代表。然后，我们将我们集合中的这些货架变化的 GCM 指标（A1B 下）与 RCP6.0 和 RCP8.5 场景下多个 CMIP5 模型的相同测量值进行比较。对于我们的整体而言，这些指标的分布落在 CMIP5 模型的范围内（特别是在 RCP8.5 下），这表明我们的货架预测将与 CMIP5 模型驱动的整体预测一致。
There are a number of sources of uncertainty that impact climate projections for regional seas. We have assessed the impact that uncertain large-scale climate forcings have on the projections for the north-west European shelf seas. An ensemble of global Atmosphere-Ocean climate model (GCM) projections made by perturbed (atmospheric) parameter model variants which were designed to span uncertainty in climate sensitivity, was dynamically downscaled with the shelf seas model POLCOMS. The simulations were run as transient experiments (from 1952 to 2098) under a medium emissions scenario (SRES A1B). This study has focused on centennial changes over the period 2069–2098 relative to 1960–1989, but also refers to the full transient simulation to assess the significance of projected changes given interannual and low-frequency variability. The ensemble mean of the POLCOMS projections showed a shelf and annual mean Sea Surface Temperature (SST) rise of 2.90 °C (±2σ= 0.82 °C), and a Sea Surface Salinity (SSS) freshening of −0.41 psu (±2σ= 0.47 psu) between these periods. We described the spread in a field for a particular period using the variances associated with both the time mean ensemble dispersion (ensemble variance) and with the interannual variability. For SST in the present-day period, the magnitudes of both ensemble and interannual variance were fairly spatially homogenous. While the future interannual variance is of similar magnitude to that of the present day, the ensemble variance increased considerably into the future period. For SSS, both sources of variance were more spatially heterogeneous, and both increased into the future period. We investigated relationships between the projected shelf seas changes across the ensemble and changes in the large-scale climate forcing. We found that the near surface-air temperature from the driving GCM (averaged over the domain) and the GCM surface salinity to the west of the POLCOMS domain are good proxies for the changes within the shelf seas. We then compared these GCM indicators of shelf changes in our ensemble (under A1B) to the same measures across a number of CMIP5 models, under the RCP6.0 and RCP8.5 scenarios. The spread of these indicators, for our ensemble, fall within the range of the CMIP5 models (particularly under RCP8.5), suggesting our shelf projections would be consistent with an ensemble of projections driven by CMIP5 models.
影响因子：
5.2
作者：
Harvey, B. J.;Shaffrey, L. C.;Hodges, K. I.
通讯作者：
Hodges, K. I.