황해 남부와 동중국해 북부 해역에서 해수 고유의 광 특성을 이용한 염분 추정 연구

Abstract

It is known that low salinity water appears in the southern Yellow Sea and northern East China Sea during summer every year. This low salinity water damages the aquaculture farms around the coastal area of Jeju island. Until now, in situ observations by ship is used for detecting the low salinity water in these waters with the spatial and temporal limitation. Remote sensing is essential to monitor the low salinity waters. Suh et al. (2004) developed a technique based on the salinity-turbidity relationship for estimating the salinity from ocean color satellite data. However, this technique did not seem to be effective because suspended solid particles are slowly sunk into bottom with the lapse of time. The objectives are to understand the relationship between salinity and absorption coefficient of dissolved organic matter (adom) and to develop the salinity estimation algorithm for ocean color satellite data. Radiometric measurements were made using WETLabs AC-S, TriOS RAMSES ACC/ARC, and ASD FieldSpec Pro Dual VNIR Spectroradiometer. Seawater samples were collected concurrently with the radiometric measurements at about 200 points around the Korean Sea during 1998 to 2006. The absorption coefficients were determined using Perkin-Elmer Lambda 19 dual-beam spectrophotometer. The value of adom(λ) increases with decreasing salinity and decreases with increasing salinity. The relationship of salinity and adom(400), adom(412), adom(443), adom(490) showed R2 values of 0.840, 0.809, 0.742 and 0.664, respectively. The estimation of salinity from SeaWiFS data is feasible with the relationship of salinity and adom(412). We developed an salinity algorithm using IOP from the relationship of adom(412) and Rrs(412)/Rrs(555). This algorithm was employed on SeaWiFS imagery to estimate salinity in the southern Yellow Sea and northern East China Sea.