Climatology of Severe Local Storm Environments and Synoptic-Scale Features over North America in ERA5 Reanalysis and CAM6 Simulation
Climatology of Severe Local Storm Environments and Synoptic-Scale Features over North America in ERA5 Reanalysis and CAM6 Simulation
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ERA5 再分析和 CAM6 模拟中北美地区严重局地风暴环境和天气尺度特征的气候学
DOI：
10.1175/jcli-d-19-0986.1
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发表时间：
2020
影响因子：
4.9
通讯作者：
Dawson II, Daniel T.
中科院分区：
文献类型：
--
作者：
Li, Funing;Chavas, Daniel R.;Reed, Kevin A.;Dawson II, Daniel T.
强烈的局地风暴（SLS）活动发生在特定的热力学和运动学环境中。这些环境通常与关键的天气尺度特征相关，包括向南的大平原低空急流、干线、高架混合层和热带气旋，这些特征将大尺度气候与SLS环境联系起来。这项工作分析了1980-2014年北美地区ERA 5再分析和社区大气模型第6版（CAM 6）历史模拟中SLS环境参数和天气尺度特征极值的时空分布。与无线电探空仪相比，ERA 5成功地再现了SLS环境，具有很强的时空相关性和低偏差，特别是在大平原地区。ERA 5和CAM 6都再现了美国中部SLS环境的气候学及其强烈的季节和日周期。ERA 5和CAM 6也再现了天气尺度特征的气候发生，其分布格局与SLS环境相似。与ERA 5相比，CAM 6在美国东部的对流可用势能中表现出高偏差，主要是由于表面水分的高偏差，以及在较小程度上，由于增强的低空风引起的风暴相对螺旋度。复合分析表明，在ERA 5和CAM 6中，美国东半部大部分地区的天气异常模式有利于显著的SLS环境，尽管美国东南部的模式不同。总体而言，我们的研究结果表明，ERA 5和CAM 6都能够再现SLS环境以及产生它们的天气尺度特征和瞬态事件。
Severe local storm (SLS) activity is known to occur within specific thermodynamic and kinematic environments. These environments are commonly associated with key synoptic-scale features—including southerly Great Plains low-level jets, drylines, elevated mixed layers, and extratropical cyclones—that link the large-scale climate to SLS environments. This work analyzes spatiotemporal distributions of both extreme values of SLS environmental parameters and synoptic-scale features in the ERA5 reanalysis and in the Community Atmosphere Model, version 6 (CAM6), historical simulation during 1980–2014 over North America. Compared to radiosondes, ERA5 successfully reproduces SLS environments, with strong spatiotemporal correlations and low biases, especially over the Great Plains. Both ERA5 and CAM6 reproduce the climatology of SLS environments over the central United States as well as its strong seasonal and diurnal cycles. ERA5 and CAM6 also reproduce the climatological occurrence of the synoptic-scale features, with the distribution pattern similar to that of SLS environments. Compared to ERA5, CAM6 exhibits a high bias in convective available potential energy over the eastern United States primarily due to a high bias in surface moisture and, to a lesser extent, storm-relative helicity due to enhanced low-level winds. Composite analysis indicates consistent synoptic anomaly patterns favorable for significant SLS environments over much of the eastern half of the United States in both ERA5 and CAM6, though the pattern differs for the southeastern United States. Overall, our results indicate that both ERA5 and CAM6 are capable of reproducing SLS environments as well as the synoptic-scale features and transient events that generate them.
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影响因子：
3.2
作者：
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DOI：
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发表时间：
1984
期刊：
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通讯作者：
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DOI：
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发表时间：
1974
期刊：
影响因子：
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作者：
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通讯作者：
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影响因子：
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作者：
Harvey, B. J.;Shaffrey, L. C.;Woollings, T. J.
通讯作者：
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