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GRAPES全球模式的动能谱分析

  

  1. 1.解放军理工大学气象海洋学院,江苏 南京 211101;2.中国人民解放军72517部队,山东 济南 250022
  • 收稿日期:2014-10-13 出版日期:2015-04-30 发布日期:2014-12-17
  • 通讯作者: 何宏让,教授,主要从事数值模拟与数值预报研究.
  • 作者简介:王亚华(1990- ),女,硕士研究生,主要从事数值模拟与资料同化研究. E-mail:wyhqxxy@163.com
  • 基金资助:

    公益性行业(气象)专项(GYHY201206007)和国家自然科学基金(41275128)共同资助

The Kinetic Energy Spectrum Analysis Based on the Global GRAPES Model

  1. 1. College of Meteorology and Oceanography,PLA University of Science and Technology, Nanjing 211101, China;2. No.72517 Unit of PLA,Ji’nan 250022,China
  • Received:2014-10-13 Online:2015-04-30 Published:2014-12-17

摘要:

大量的观测资料表明在对流层高层和平流层低层,大气动能谱在大尺度范围(800 km以上)与波数呈现出-3的斜率关系,而过渡到中尺度范围(400 km以下)二者呈现出-5/3的斜率关系。模式预报结果能否展现大气动能谱的这种斜率转折特征已经成为模式评估的有效方法。本文采用GRAPES全球中期数值预报模式2013年5月的预报结果,计算了模式一维和二维动能谱,并分析了二维谱的旋转分量与辐散分量、平均分量与扰动分量的关系。结果表明,GRAPES模式的一维谱和二维谱结果均能较好地表现出动能谱的斜率转折特征,但该模式动能谱在中尺度范围的斜率绝对值明显比观测结果和其它模式结果偏大;二维谱的旋转分量和辐散分量、平均分量和扰动分量在总动能谱中的比重关系及其随高度的变化均与文献结果较为一致。总之,GRAPES模式整体上较好地再现了大气动能谱的各种特征,但是可能由于模式分辨率和耗散作用的影响,模式对大气中尺度波动的描述还不够充分。

关键词: GRAPES全球模式, 动能谱, 模式评估

Abstract:

The atmosphere kinetic spectrum in the free troposphere and lower stratosphere exists a dependence of k -3 (k is the slope) on wavenumber for large scale(more than 800 km) system, while that is k -5/3 for mesoscale(less than 400 km)systems based on the observation data,which have been seen as a basic characteristic of free atmosphere. Whether the predicted results of model can display the slope turning characteristic of kinetic energy spectrum has been an effective method of model evaluation. In the article, the one and two dimensional kinetic energy spectrums of global GRAPES model were calculated based on the simulated results in May 2013, and the relations between the rotational and divergence components, stationary and transient components to the kinetic energy were analyzed. The results showed that the simulated one and two dimensional kinetic energy spectrums of GRAPES model could show the transition characteristic of the slope from large scale range to mesoscale range, however the absolute values of the slope in mesoscale range were obviously steeper than the observation and other models. The proportions of the rotational and divergent components, stationary and transient components in total kinetic energy spectrum and their changes with height were also consistent with the results of other articles. All in all, GRAPES could better reproduce the characteristics of the kinetic energy spectrum of real atmosphere, but was poor in description of the mesoscale fluctuation due to the effect of the resolution of model andatmospheric drag.

Key words: GRAPES model, kinetic energy spectrum, model evaluation

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