| JIAO Lin,ZHANG Yonggang. 2015. An evaporation duct prediction model coupled with the MM5. Acta Oceanologica Sinica, 34(5):46－50 |
| An evaporation duct prediction model coupled with the MM5 |
| 一个嵌套于MM5下的蒸发波导预报模式 |
| Received:March 31, 2014 Revised:January 26, 2015 |
| DOI：10.1007/s13131-015-0666-z |
| Key words:evaporation duct diagnosis mesoscale model (MM5) evaporation duct prediction model numerical simulation |
| 中文关键词: 蒸发波导诊断 中尺度模式MM5 蒸发波导预报模式 数值模拟 |
| 基金项目:Dalian Naval Academy Scientific Research Fund. |
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| Abstract: |
| Evaporation duct is an abnormal refractive phenomenon in the marine atmosphere boundary layer. It has been generally accepted that the evaporation duct prominently affects the performance of the electronic equipment over the sea because of its wide distribution and frequent occurrence. It has become a research focus of the navies all over the world. At present, the diagnostic models of the evaporation duct are all based on the Monin-Obukhov similarity theory, with only differences in the flux and character scale calculations in the surface layer. These models are applicable to the stationary and uniform open sea areas without considering the alongshore effect. This paper introduces the nonlinear factor αv and the gust wind item wg into the Babin model, and thus extends the evaporation duct diagnostic model to the offshore area under extremely low wind speed. In addition, an evaporation duct prediction model is designed and coupled with the fifth generation mesoscale model (MM5). The tower observational data and radar data at the Pingtan island of Fujian Province on May 25-26, 2002 were used to validate the forecast results. The outputs of the prediction model agree with the observations from 0 to 48 h. The relative error of the predicted evaporation duct height is 19.3% and the prediction results are consistent with the radar detection. |
| 中文摘要: |
| 蒸发波导是一种发生在海气边界层的异常折射现象, 由于其分布范围广、发生概率大, 被认为是对海上电子设备影响最为显著的波导类型, 成为世界各国海军竞相研究的焦点。目前的蒸发波导诊断模式, 基本原理都是基于Monin-Obukhov 相似理论, 只是用于确定近地层通量和特征尺度的方法不同, 而且仅适用于定常和水平均匀的开阔海域, 并没有考虑蒸发波导的近岸效应。针对这一问题, 本文将张强、胡隐樵的通量廓线关系即非线性修正因子αv与阵性风速wg引入到蒸发波导诊断的Babin 模式中, 从而将该模式的适用范围扩展到沿海近岸地区和甚低风速条件下。此外本文将改进的Babin模式嵌套于中尺度模式MM5 下, 发展建立了一个海洋蒸发波导高度预报模式, 并利用2002年5月25-26日福建平潭岛的铁塔数据与雷达探测资料, 对预报模式的输出结果进行验证。验证结果表明:在0-48小时内预报模式的输出值与实测值拟和较好且变化规律一致, 蒸发波导高度预报的平均误差为0.193, 预报结果与雷达实际探测结果一致。 |
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