Based on FY-2E satellite image from 2005 to 2010,the weather data of 28 heavy fog events along the coast and meteorological data from island weather stations from 2008 to 2010,the satellite cloud image with aero-logical sounding data,the surface weather chart was overlaid and temperature of the inversion layer profile of temperature field and black body temperature (TBB) values were compared with sea surface temperature, and the areas and depth of sea fog, the temperature in fog region in autumn and winter were evaluated with MICAPS 3.0 system by the atmospheric static equation and thermodynamic theory. The results indicate that the fog monitored with infrared image and visible cloud image changes from light fog to heavy fog along the coast of Dalian, Yantai and Tianjin under special circulation background around the Bohai sea regions, and it moves to the north along the coast. The vertical depth of fog reaches 400-600 m, the lapse rate of temperature is 0.02-0.04 ℃/100 m. The difference values of temperature are 1-2 ℃ and 3-5 ℃ between the east and the west directions and between the south and the north directions in the Bohai sea,respectively. Radiative fog and advection fog are associated with weakly high and low pressure fields,respectively. The heavy fog is strengthened for the fog area is covered by the low cloud,while the visibility of the light fog is weakened because of the overlaying of low cloud. The advection fog is mixed into water vapor conveyer belt of low level after it is lifted by the frontal surface,which is indicative to subsequent snowfall or rainfall. The effect of forecasting for these heavy fog events during 2009-2010 is good in terms of the above mentioned method,and it could provide guidelines for selecting the forecasting factors and improving the work flow of forecasting and monitoring operation of heavy fog events.%利用2005-2010年卫星云图FY-2E、海岸带-海区出现的28次大雾天气资料和2008-2010年海岛站资料,依据大气状态方程、热力学原理,在MICAPS 3.0系统下,应用云图与同步探空、地面雾区叠加图、温度场逆温层剖面及TBB值与海面温度比较,估算雾区面积、高度及秋、冬季雾区温度垂直递减率.结果表明:在环渤海地区特定的环流背景下,红外云图和可见光云图监测到的雾区分别在大连、烟台及天津一带由轻雾转为大雾,沿海岸带向北发生发展,雾区垂直厚度为400-600 m,递减率为0.02-0.04℃/100 m,渤海东西向温度差值为1-2℃,南北向为3-5℃;辐射雾对应弱高压均压场,平流雾对应弱低压均压场;低云覆盖雾区浓雾加重,轻雾被低云叠加使得能见度降低;平流雾被锋面抬升后混合到低空水汽输送带之中,对后期降雪(水)具有指示作用.在2009-2010年海区-海岸带大雾天气预报及预警信号升级应用中效益显著,可为海岸带大雾预报因子选取及预报监测业务流程的改进提供参考.
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