동북아시앙 해역 클로로필-a 농도의 중기 변동성에 대한 양자강 방출수의 영향

Abstract

The Changjiang River, the longest river in Asia, is major a source of nutrient and freshwater for the East China Sea (ECS). Many previous studies reported that the Changjiang Diluted Water (CDW) affects the chlorophyll-a (chl-a) concentration of the ECS and flows into the East/Japan Sea. However there is no study which reported about the impact of CDW on the chl-a concentration variability and its spatial scale in the East/Japan Sea. Therefore, in this study we investigated the spatial scale of CDW-affected patches and the effect of CDW on chl-a of East/Japan Sea using 10-year monthly mean chl-a dataset obtained from Sea-Viewing Field-of-view Sensor (SeaWiFS).In this study, we removed seasonality of the chl-a concentration by subtracting monthly mean from the chl-a concentration in each pixel. We also used lagged correlation between anomalies of chl-a concentrations and Changjiang discharge to consider that summer changjiang discharge move to eastward with a time lag after discharge. The strong positively correlated patch between two parameters gradually moved to eastward with time lags. Strong positive correlation was found near the Changjiang River mouth, the south of Jeju Island, the Korea Strait, and the south of East/Japan Sea, with the lag times of 0-1 month, 1-3 months, and 3 months, respectively. It seems that the strong positive correlated patches in the ECS and the south of Korean Peninsula were affected on of the ECS and flows into the East/Japan Sea. However there is no study which reported about the impact of CDW on the chl-a concentration variability and its spatial scale in the East/Japan Sea. Therefore, in this study we investigated the spatial scale of CDW-affected patches and the effect of CDW on chl-a of East/Japan Sea using 10-year monthly mean chl-a dataset obtained from Sea-Viewing Field-of-view Sensor (SeaWiFS).In this study, we removed seasonality of the chl-a concentration by subtracting monthly mean from the chl-a concentration in each pixel. We also used lagged correlation between anomalies of chl-a concentrations and Changjiang discharge to consider that summer changjiang discharge move to eastward with a time lag after discharge. The strong positively correlated patch between two parameters gradually moved to eastward with time lags. Strong positive correlation was found near the Changjiang River mouth, the south of Jeju Island, the Korea Strait, and the south of East/Japan Sea, with the lag times of 0-1 month, 1-3 months, and 3 months, respectively. It seems that the strong positive correlated patches in the ECS and the south of Korean Peninsula were affected