首页> 外文OA文献 >The effects of explicit versus parameterized convection on the MJO in a large-domain high-resolution tropical case study. Part I: Characterization of large-scale organization and propagation
【2h】

The effects of explicit versus parameterized convection on the MJO in a large-domain high-resolution tropical case study. Part I: Characterization of large-scale organization and propagation

机译:在大范围高分辨率热带案例研究中,显式对流与参数化对流对MJO的影响。第一部分:大规模组织和传播的特征

代理获取
本网站仅为用户提供外文OA文献查询和代理获取服务,本网站没有原文。下单后我们将采用程序或人工为您竭诚获取高质量的原文,但由于OA文献来源多样且变更频繁,仍可能出现获取不到、文献不完整或与标题不符等情况,如果获取不到我们将提供退款服务。请知悉。

摘要

High-resolution simulations over a large tropical domain (∼20◦S–20◦N and 42◦E–180◦E) using both explicit and parameterized convection are analyzed and compared to observations during a 10-day case study of an active Madden-Julian Oscillation (MJO) event. The parameterized convection model simulations at both 40 km and 12 km grid spacing have a very weak MJO signal and little eastward propagation. A 4 km explicit convection simulation using Smagorinsky subgrid mixing in the vertical and horizontal dimensions exhibits the best MJO strength and propagation speed. 12 km explicit convection simulations also perform much better than the 12 km parameterized convection run, suggesting that the convection scheme, rather than horizontal resolution, is key for these MJO simulations. Interestingly, a 4 km explicit convection simulation using the conventional boundary layer scheme for vertical subgrid mixing (but still using Smagorinsky horizontal mixing) completely loses the large-scale MJO organization, showing that relatively high resolution with explicit convection does not guarantee a good MJO simulation. Models with a good MJO representation have a more realistic relationship between lower-free-tropospheric moisture and precipitation, supporting the idea that moisture-convection feedback is a key process for MJO propagation. There is also increased generation of available potential energy and conversion of that energy into kinetic energy in models with a more realistic MJO, which is related to larger zonal variance in convective heating and vertical velocity, larger zonal temperature variance around 200 hPa, and larger correlations between temperature and ascent (and between temperature and diabatic heating) between 500–400 hPa.
机译:在一个活跃的Madden的为期10天的案例研究中,使用显式对流和参数化对流对大型热带区域(〜20°S–20°N和42°E–180°E)进行高分辨率模拟,并将其与观测结果进行比较-朱利安震荡(MJO)事件。在40 km和12 km网格间距处的参数化对流模型模拟的MJO信号非常弱,向东传播很小。在垂直和水平方向上使用Smagorinsky子网格混合进行的4 km显式对流模拟显示出最佳的MJO强度和传播速度。 12 km显性对流模拟的性能也比12 km参数化对流运行好得多,这表明对流方案而非水平分辨率是这些MJO模拟的关键。有趣的是,使用常规边界层方案进行垂直子网格混合(但仍使用Smagorinsky水平混合)的4 km显性对流模拟完全失去了大型MJO组织,这表明具有显性对流的相对高分辨率不能保证良好的MJO模拟。具有良好MJO表示的模型在较低的对流层湿度与降水之间具有更现实的关系,从而支持了水分对流反馈是MJO传播的关键过程的观点。在具有更现实的MJO的模型中,可用势能的产生也越来越多,并且将该能转换为动能,这与对流加热和垂直速度的较大区域变化,200 hPa附近的较大区域温度变化以及更大的相关性有关。在温度和上升之间(以及温度和非绝热加热之间)在500–400 hPa之间。

著录项

相似文献

  • 外文文献
  • 中文文献
代理获取

客服邮箱:kefu@zhangqiaokeyan.com

京公网安备:11010802029741号 ICP备案号:京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有
  • 客服微信

  • 服务号