Robust future precipitation declines in CMIP5 largely reflect the poleward expansion of model subtropical dry zones
Robust future precipitation declines in CMIP5 largely reflect the poleward expansion of model subtropical dry zones
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DOI：
10.1029/2012gl052910
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发表时间：
2012-09-21
影响因子：
5.2
通讯作者：
Frierson, Dargan M. W.
中科院分区：
文献类型：
--
作者：
Scheff, Jack;Frierson, Dargan M. W.
副热带降水的强劲下降一直是大气环流模型（GCM）对未来温室变暖响应的一个突出特征。作者最近的工作表明，对于构成耦合模型比对项目第 3 阶段 (CMIP3) 的模型，这种干燥主要发生在模型副热带降水极小值的中纬度驱动降水极地。在这里，使用更全面的诊断，我们将这项工作扩展到 36 个新的 CMIP5 模型，并发现 CMIP5 降水的强劲下降也主要出现在副热带最低值和中纬度降水最高值之间，这意味着干区动态向极地扩张，而不是干湿对比的热力学放大。我们还给出了这些预计下降的完整季节周期，表明它们在当地春季比当地秋季更为普遍，并且在北半球一年中的大部分时间里，它们完全局限于地球的大西洋一侧。引用：Scheff, J. 和 D. M. W. Frierson (2012)，CMIP5 未来降水量的强劲下降很大程度上反映了模型副热带干旱区向极地的扩张，Geophys。资源。快报，39，L18704，doi：10.1029/2012GL052910。
Robust subtropical precipitation declines have been a prominent feature of general circulation model (GCM) responses to future greenhouse warming. Recent work by the authors showed that for the models making up the Coupled Model Intercomparison Project phase 3 (CMIP3), this drying was found mainly in the midlatitude-driven precipitation poleward of the model subtropical precipitation minima. Here, using more comprehensive diagnostics, we extend that work to 36 new CMIP5 models, and find that CMIP5 robust precipitation declines are also found mainly between subtropical minima and midlatitude precipitation maxima, implicating dynamic poleward expansion of dry zones rather than thermodynamic amplification of dry-wet contrasts. We also give the full seasonal cycle of these projected declines, showing that they are much more widespread in local spring than in local fall, and that for most of the year in the Northern Hemisphere they are entirely confined to the Atlantic side of the globe. Citation: Scheff, J., and D. M. W. Frierson (2012), Robust future precipitation declines in CMIP5 largely reflect the poleward expansion of model subtropical dry zones, Geophys. Res. Lett., 39, L18704, doi: 10.1029/2012GL052910.