An observational and modeling study of a sea fog event over the yellow and east China seas on 17 March 2014

The Moderate Resolution Imaging Spectroradiometer(MODIS) satellite imagery,weather charts,objectively reanalyzed data,the observational data and station sounding data were analyzed to investigate a sea fog event occurred over the Yellow and East China Seas on March 17,2014.The sounding profiles,weather situations and the related meteorological factors during the development and dissipation stages of this sea fog event were documented.Weather Research Forecast(WRF) model was applied to simulate this sea fog case.The simulated horizontal atmospheric visibility,cloud water,humidity,and vertical wind profile during the different stages of this fog event were analyzed.During the development stage of this sea fog,a southerly lower-jet with 16-18 ms-1,an inversion layer and a cold center over the Yellow Sea were detected.The relative humidity in the fog area was above 95%.The specific humidity over the East China Sea was higher than that over the Yellow Sea.Southerly was dominated in fog area.However,during the dissipation stage of this sea fog,westerly replaced the southerly and at the lower level,southerly jet disappeared.A dry air area formed over the Shandong Peninsula and moved eastwards.Moreover,the WRF modeling result showed that the simulated atmospheric horizontal visibility and cloud water were approximately consistent with the MODIS satellite imagery.Most of cloud water concentrated below 200-400 m,and the cloud water in the southern part of fog area extended to a higher height than the northern part.While both of air temperature and dew-point temperature were close to sea surface temperature.