Impact of Ocean Eddy Resolution on the Sensitivity of Precipitation to CO2 Increase
Impact of Ocean Eddy Resolution on the Sensitivity of Precipitation to CO2 Increase
复制标题
海洋涡分辨率对降水对二氧化碳增加敏感性的影响
DOI：
10.1029/2018gl078235
复制
发表时间：
2018
影响因子：
5.2
通讯作者：
M. Winton
中科院分区：
文献类型：
--
作者：
Jie He;B. Kirtman;B. Soden;G. Vecchi;Honghai Zhang;M. Winton
在过去的几年里，全球涡旋分辨海洋模式的开发投入越来越多，但将如此高的海洋分辨率纳入降水对CO2强迫的响应的影响还有待研究。这项研究分析了一套地球物理流体动力学实验室模型的降水变化，该模型包括涡动解析（0.1°），涡动允许（0.25°）和涡动参数化（1°）海洋模型。涡动分辨率的引入并没有挑战降水变化的大尺度结构，但会导致显著的区域差异，特别是在海洋上。这些海洋差异主要是由海表温度（SST）变化模式驱动的，在低纬度地区更敏感。海洋分辨率对SST变化的最大影响发生在涡流丰富的区域（例如，边界流和南大洋），对降水变化也有不同程度的影响。在墨西哥湾流地区，以前的研究发现相当大的影响，涡分辨率的气候降水模拟，我们没有发现这样的影响，从地球物理流体动力学实验室模型，但我们发现降水变化的重大影响。涡动参数化模型预测了耦合模型相互比较项目（第5阶段）模型常见的带状结构，而更高分辨率的模型预测了与墨西哥湾流变暖增强相关的降水最大值的极移。在陆地上，降水变化一般对海洋分辨率不太敏感。在邻近墨西哥湾流区域的北美东部，分辨率之间存在中度差异。我们讨论了陆地差异的机制，这是通过模拟气候SST和SST变化而产生的。
The past few years have seen a growing investment in the development of global eddy‐resolving ocean models, but the impact of incorporating such high ocean resolution on precipitation responses to CO2 forcing has yet to be investigated. This study analyzes precipitation changes from a suite of Geophysical Fluid Dynamics Laboratory models incorporating eddy‐resolving (0.1°), eddy‐permitting (0.25°), and eddy‐parameterizing (1°) ocean models. The incorporation of eddy resolution does not challenge the large‐scale structure of precipitation changes but results in substantial regional differences, particularly over ocean. These oceanic differences are primarily driven by the pattern of sea surface temperature (SST) changes with greater sensitivity in lower latitudes. The largest impact of ocean resolution on SST changes occurs in eddy‐rich regions (e.g., boundary currents and the Southern Ocean), where impact on precipitation changes is also found to various degrees. In the Gulf Stream region where previous studies found considerable impact of eddy resolution on the simulation of climatological precipitation, we do not find such impact from the Geophysical Fluid Dynamics Laboratory models, but we do find substantial impact on precipitation changes. The eddy‐parameterizing model projects a banded structure common to the Coupled Model Intercomparison Project (Phase 5) models, whereas the higher‐resolution models project a poleward shift of precipitation maxima associated with an enhanced Gulf Stream warming. Over land, precipitation changes are generally not very sensitive to ocean resolution. In eastern North America adjacent to the Gulf Stream region, moderate differences are found between resolutions. We discuss the mechanisms of land differences, which arise through the simulation of both climatological SST and SST changes.