봄철 동해 남서부해역에서 유색용존유기물의 분포 특성

Abstract

The distribution and spatial-temporal variability of chromophoric dissolved organic matter(CDOM) in the southwestern East sea were examined during two cruises in May 2012 and 2014. Absorption coefficient(aCDOM(355)) in spring 2012 and 2014 was 0.185 ± 0.050(0.009∼0.369) m-1, 0.287 ± 0.083(0.059∼0.619) m-1, respectively. These levels are quite high as compared with reports from other marginal seas similar to East sea. Spatial and temporal variability of CDOM was clear. Spatial variation of two years were quite different. In 2012, CDOM levels declined from coastal zone to offshore, whereas CDOM levels were generally high, showed similar level in coastal zone and offshore in 2014. Temporal variation of CDOM was also evident. This is the result of difference in the environmental conditions according to time. In 2012, we conducted the examination at the end of May, the time of primary production is decreasing. In 2012 CDOM and Chl a showed any correlation while they seemed positive correlation in 2014. Therefore the effect of in situ production accompanying active primary production may be smaller in 2012 compared to 2014. Dilution of CDOM caused by vertical mixing as well as input of low saline water that has low CDOM levels and photobleaching made CDOM levels low in spring. It was identified that CDOM levels at southwestern East sea in spring tend to increase during 4 years(2011∼2014) by previous and this study. This result is very important because it reflects change of the ocean environment according to climate change. Because the increase of CDOM can accelerate climate change, the ongoing research and understanding about CDOM is needed.