Huge size of HABs monitoring using GOCI in the South and East Sea of Korea

Abstract

Huge size of harmful algal blooms (HABs), so-called red tide, broke out in the southeastern coastal area of Korea and it spread to the coastal area of East Sea in summer of 2013. Outbreaks of HABs in Korea were sporadic until the 1980s, and became frequent during the 1990s (Kim, 2012). But broad-scale occurrence of HABs in 2013 was exceptional and led to the worst economic loss for the coastal fishing farms. Red tide monitoring is one of key mission for GOCI (Geostationary Ocean Color Imager) (Ahn, 2012). GOCI has two spectral bands for fluorescence signals (FS), one is a band centered at 660 nm for the base of FS and the other one is a band centered at 680 nm for the maximum of FS similar with the MERIS (MEdium Resolution Imaging Spectrometer). Owing to these two bands for FS, GOCI has an advantage for the HABs detection. Besides, 1 hour observation internal of GOCI is also helpful to monitor detailed patterns of HABs patches movement. In this study, distribution and movement patterns of HABs, occurred on the South and East Sea in summer 2013, were monitored using GOCI. On the middle of July, some small patches appeared in the coastal area of South Sea and moved to the eastern area. On the end of July, HABs patches were widely distributed in the southeastern area of South Sea and it flowed to the East Sea along with the shoreline. And in the beginning of August, large patch (50 km x 50 km) appeared in the south part became frequent during the 1990s (Kim, 2012). But broad-scale occurrence of HABs in 2013 was exceptional and led to the worst economic loss for the coastal fishing farms. Red tide monitoring is one of key mission for GOCI (Geostationary Ocean Color Imager) (Ahn, 2012). GOCI has two spectral bands for fluorescence signals (FS), one is a band centered at 660 nm for the base of FS and the other one is a band centered at 680 nm for the maximum of FS similar with the MERIS (MEdium Resolution Imaging Spectrometer). Owing to these two bands for FS, GOCI has an advantage for the HABs detection. Besides, 1 hour observation internal of GOCI is also helpful to monitor detailed patterns of HABs patches movement. In this study, distribution and movement patterns of HABs, occurred on the South and East Sea in summer 2013, were monitored using GOCI. On the middle of July, some small patches appeared in the coastal area of South Sea and moved to the eastern area. On the end of July, HABs patches were widely distributed in the southeastern area of South Sea and it flowed to the East Sea along with the shoreline. And in the beginning of August, large patch (50 km x 50 km) appeared in the south part