A dual channel difference (DCD) method is applied to detect nighttime sea fog/stratus over the Huanghai Sea using the infrared (IR) data of shortwave (3.5-4.0 μm) and longwave (10.3-11.3 μm) channels from th...A dual channel difference (DCD) method is applied to detect nighttime sea fog/stratus over the Huanghai Sea using the infrared (IR) data of shortwave (3.5-4.0 μm) and longwave (10.3-11.3 μm) channels from the Multi-functional Transport Satellite (MTSAT)-IR, i.e., shortwave minus longwave brightness temperature difference (SLTD). Twenty-four sea fog events over the Huanghai Sea during March to July of 2006 and 2007 are chosen to determine a suitable value of SLTD for nighttime sea fog/stratus detection, and it is found that the value of-5.5-2.5℃ can be taken as a criterion. Two case examples of sea fog events are especially demonstrated in detail utilizing the criterion, and the results show that the derived sea fog/stratus coverage is quite reasonable. This coverage information is very helpful to analyze the formation and evolution of sea fog/stratus during night and can provide sea fog researchers with observational evidences for model results verification. However, more efforts are needed to further obtain vertical extent information of sea fog/stratus and attempt to discriminate between sea fog and stratus.展开更多
基金The National Natural Science Foundation of China under contract No. 40706004the National Basic Research Program ("973" program) of China under contract No. 2005CB422301+2 种基金China Meteorological Administration’s New Technology Extension Project under contract No. CMATG2008M41the National Special Fund for public Sector Research of China under contract No. GYHY200706031Shandong Provincial Meteorological Bureau Science Fund of China under contract No. 2004SDQXJ01.
文摘A dual channel difference (DCD) method is applied to detect nighttime sea fog/stratus over the Huanghai Sea using the infrared (IR) data of shortwave (3.5-4.0 μm) and longwave (10.3-11.3 μm) channels from the Multi-functional Transport Satellite (MTSAT)-IR, i.e., shortwave minus longwave brightness temperature difference (SLTD). Twenty-four sea fog events over the Huanghai Sea during March to July of 2006 and 2007 are chosen to determine a suitable value of SLTD for nighttime sea fog/stratus detection, and it is found that the value of-5.5-2.5℃ can be taken as a criterion. Two case examples of sea fog events are especially demonstrated in detail utilizing the criterion, and the results show that the derived sea fog/stratus coverage is quite reasonable. This coverage information is very helpful to analyze the formation and evolution of sea fog/stratus during night and can provide sea fog researchers with observational evidences for model results verification. However, more efforts are needed to further obtain vertical extent information of sea fog/stratus and attempt to discriminate between sea fog and stratus.