| 摘要: |
| 2009年4月9—12日黄海海域发生了一次受高压系统影响的海雾过程。利用卫星观测与探空数据、WRF模式(Weather Research and Forecasting Model)对此次海雾过程及相伴的大气波导进行了观测分析与数值模拟。海雾与波导发展可分为3个阶段: (1)大气波导先于海雾存在于黄海海面; 受高压下沉影响, 黄海上空存在逆温层和较强的湿度梯度, 表现为较强的贴海表面波导和非贴海表面波导。(2)海雾始于高压西部, 并随高压系统逐渐东移减弱, 向黄海北部扩展; 辐射冷却虽然使雾顶附近逆温增强, 但海雾的机械湍流使其顶部湿度梯度减小, 雾顶附近对应弱悬空波导或波导消失。(3)高压系统影响使干空气下沉到雾区导致黄海海雾消散; 雾顶附近逆温仍存在, 同时湿度梯度增大, 黄海上空逐渐变为非贴海表面波导。本研究结果表明: 高压系统不仅极易为波导的发生提供有利条件, 而且有利于海雾的生成, 在海雾演变过程中主要是雾顶水汽梯度的变化导致了波导类型及强度的变化。 |
| 关键词: 黄海 大气波导 海雾 WRF模式(Weather Research and Forecasting Model) 观测分析 数值模拟 |
| DOI：10.11693/hyhz20130500060 |
| 分类号: |
| 基金项目:国家自然科学基金项目, 41276009 号 |
相关附件： Figures.zip |
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| MODELING MARINE ATMOSPHERIC DUCT FORMATION FOR A TYPICAL FOG ON YELLOW SEA |
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YUAN Xia-yu and GAO Shan-hong
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Key Laboratory of Physical Oceanography,Ocean-Air Interaction and Climate Laboratory,Ocean University of China,Qingdao,Key Laboratory of Physical Oceanography,Ocean-Air Interaction and Climate Laboratory,Ocean University of China,Qingdao
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| Abstract: |
| We selected and investigated a typical sea fog event that occurred on the Yellow Sea on April 9—12, 2009 in a high-pressure system. Using FNL (the Final Analyses) results as the initial boundary data, we employed WRF (Weather Research and Forecasting) model to reproduce the duct of the event. The results are followed. (1) An atmospheric duct appeared before the sea fog formation. Due to strong subsidence over the Yellow Sea, humidity gradient was large and inversion layer occurred. Both touching-sea-level surface duct and non-touching-sea-level surface duct appeared. (2) The sea fog initiated in the place west of a high-pressure system and extended northward when the high-pressure system was weakening and shifting eastward. No atmospheric duct existed at top of the fog, although long wave radiation strengthened the inversion at the top of the fog. Meanwhile, a non-touching-sea-level surface duct controlled the regions without fog formation. (3) Under the influence of high pressure system, dry air mass was sinking in the fog region, and the fog was gradually dissipated and vanished at last. Thus, the non-touching-sea-level surface duct over the Yellow Sea was formed due to large humidity gradient and inversion layer occurrence. In other words, the high pressure system resulted in significant temperature and humidity gradients at the top of the sea fog, and then the atmospheric duct developed. Therefore, sea fog and atmospheric duct are closely related and often co-occur. |
| Key words: Yellow Sea atmospheric duct sea fog WRF model(Weather Research and Forecasting Model) observation analysis numerical modeling study |
