해색위성 GOCI와 MODIS에서 탐지된 부유성 녹조 비교

Abstract

The massive green algae blooms, Ulva prolifera, reported in June-August 2008 around the Qingdao, Yellow Sea, East China Sea, Korea and Japan coast has occurred in a similar season and region until the present day. On June 13, 2011, around Qingdao, China, GOCI and MODIS detected an enormous bloom of floating green algae, which originated from the nearshore Subei Bank, China. The large floating green algae patches were observed along and across the Yellow Sea and in the East China Sea from June 18 to June 20, 2011, by various oceanic cruises. To detect the massive macroalgae blooms from space, an Index of floating Green Algae for GOCI (IGAG) was developed from the multiple spectral band ratios using three wavelengths (555, 660, 745 nm), which the spectral response of green algae reflected at 555, 745, and 865 nm and absorbed at 660 and 680 nm. The results were compared with those obtained by the normalized difference vegetation index (NDVI), enhanced vegetation index (EVI) using GOCI and MODIS satellite data. NDVI (or EVI) and IGAG produced similar results whether we are using MODIS or GOCI images. Usually more than 90% of EVI results were reproduced by IGAG, although the areas with green algae were greater with IGAG in most cases. Both MODIS and GOCI produced similar distribution pattern of green algae if we are using EVI or IGAG. In short GOCI is as useful as MODIS in detecting green algae blooms.Qingdao, China, GOCI and MODIS detected an enormous bloom of floating green algae, which originated from the nearshore Subei Bank, China. The large floating green algae patches were observed along and across the Yellow Sea and in the East China Sea from June 18 to June 20, 2011, by various oceanic cruises. To detect the massive macroalgae blooms from space, an Index of floating Green Algae for GOCI (IGAG) was developed from the multiple spectral band ratios using three wavelengths (555, 660, 745 nm), which the spectral response of green algae reflected at 555, 745, and 865 nm and absorbed at 660 and 680 nm. The results were compared with those obtained by the normalized difference vegetation index (NDVI), enhanced vegetation index (EVI) using GOCI and MODIS satellite data. NDVI (or EVI) and IGAG produced similar results whether we are using MODIS or GOCI images. Usually more than 90% of EVI results were reproduced by IGAG, although the areas with green algae were greater with IGAG in most cases. Both MODIS and GOCI produced similar distribution pattern of green algae if we are using EVI or IGAG. In short GOCI is as useful as MODIS in detecting green algae blooms.