【作者】 王菁茜；

【导师】 傅刚；

【作者基本信息】 中国海洋大学 ， 气象学， 2006， 硕士

【摘要】 本文对2005年3月27日黄渤海海上的一次海雾事件进行了观测分析及数值模拟研究。利用GOES-9(Geostationary Operational Environmental Satellite), MODIS (Moderate Resolution Imaging Spectroradiometer), NOAA (National Oceanic and Atmospheric Administration)和风云1D可见光卫星云图对海雾发生的范围、形态、及变化进行了观测。海雾于2005年3月27日早晨发生,雾区面积大约为11000平方公里,持续24小时左右。此次海雾对黄渤海海上能见度影响很大。海雾持续过程中,面积东西向逐渐缩减,最后演变成S形状。配合MICAPS (Meteorological Information Comprehensive Analysis and Process System)地面观测资料,对海雾的发生进行了确认。利用地面站点观测资料,了解到海雾发生时能见度主要维持在2 km以下,露点温度与温度之差和能见度的变化成正比。利用美国国家环境预报中心(National Centers for Environmental Prediction)提供的FNL (Final analysis data)资料,对海雾发生时的天气形势,气海温差和水汽的南北输送进行了分析。分析表明,海雾发生时天气形势稳定,贝加尔湖以东地区有冷高压形成;2 m气温与该处露点温度非常接近,空气湿度较大,温差小值区域与海雾发生区域相似;2 m处露点温度与海表面表皮温度差场说进一步说明,海面在接近露点温度的情况下,才可以有海雾生成;气海温差在黄渤海地区普遍>2 oC,海雾发生的中心地区气海温差最高达到5 oC。从探空资料(白翎岛,乌山,丹东,大连,青岛,射阳站)分析可看出垂直方向上存在逆温层结,而水汽输送恰恰以此逆温层为分界,说明逆温层结抑制底层水汽蒸发,起到将水汽输送固定在低层的作用。之后,本文利用科罗拉多大学开发的RAMS(Regional Atmospheric Modeling System)数值模式对此次海雾事件进行了数值模拟,并计算了水平能见度。结果表明:能见度水平分布与卫星云图所显示的雾区分部吻合较好,但模拟得到的雾区较大,海雾的出现时间较实际观测出现时间延迟4小时左右。大连站点模拟能见度的变化与地面观测能见度值的变化趋势相一致,模拟能见度值显著偏小。此外根据模式结果分析了海表面温度与露点温的关系,并由此设计了SST (Sea Surface Temperature)敏感试验。分别对海温进行升高2 oC、升高2.5 oC、降更多还原

【Abstract】 A dense sea fog happened at 27th Mar 2005. The images of GOES(Geostationary Operational Environmental Satellite), NOAA (National Oceanic and Atmospheric Administration), MODIS ( Moderate Resolution Imaging Spectroradiometer) and FY-1D and other available data such as FNL (Final analysis data) of NCEP (National Centers for Environmental Prediction), MICAPS (Meteorological Information Comprehensive Analysis and Process System), surface observation data and sounding data are used to recognize and analyze the fog. Satellite images provide information on the area and the shape of the sea fog; MICAPS and surface observation data show the visibility and the specific humidity of the sea fog. It can be seen that this sea fog affected visibility on the sea and the coast cities very seriously. FNL is used to analyze the synoptic situation, the temperature difference between the sea surface and the air two meters above the surface and the transport of specific humidity. It shows by the sounding data that there is inversion layer under 900 hPa and the vertical structure is stable. Then, RAMS model is used to simulate this sea fog event. The distribution of simulated horizontal visibility is similar to the fog region on the visible satellite images. The evolution of the visibility at Dalian station is also close to the observed visibility there. The experiments of SST (Sea Surface Temperature) sensibility show that a temperature difference of more than 2 oC between the sea surface and the air two meters above the surface is necessary to the formation of sea fog. The experiments also suggest that a low SST will limit the development of sea fog.更多还原