여름철 동해 남서부해역의 용존유기탄소의 분포 특성

Abstract

동해의 탄소순환을 이해하기 위하여 2009~2011년 여름철 3회에 걸쳐 연구해역의 용존유기탄소의 농도를 조사하였다. 또한, 용존유기탄소의 기원과 분포에 영향을 주는 원인을 알기 위해 CDOM, FDOM, Chl a의 분포를 확인하고 DOC와의 상관관계를 구하였다. 연구해역의 표층의 DOC의 농도는 2009년에 51.5~172.7μM (평균: 111.1μM), 2010년에 126.1~192.4μM (평균: 149.7μM), 2011년에 74.2~129.7μM (평균: 87.2μM)의 분포로 나타났으며, 2010년에 가장 높은 DOC 농도가 측정되었다. 2009년 (연안 평균: 121μM, 외양 평균: 106.6μM)과 2011년 (연안 평균: 92.1μM, 외양 평균: 83.6μM)은 연안에서 외양보다 높은 DOC 분포가 나타났으며, 연안에서 FDOM과 Chl a의 높은 농도패턴, salinity의 낮은 패턴이 확인되었다. 2009년에는 FDOM과 Chl a의 상관관계는 연안에서 뚜렷하게 나타나 자생기원의 영향을 확인하였으며 (연안 R2=0.8920, 외양 R2=0.2541), FDOM과 salinity의 상관관계는 연안에서 뚜렷하게 나타나 육상기원의 영향을 확인하였다 (연안 R2=0.7978, 외양 R2=0.3720). 2011년에는 FDOM과 Chl a의 상관관계는 연안과 외양 모두 뚜렷하게 나타나 자생기원의 영향을 확인하였으며 (연안 R2=0.7793, 외양 R2=0.5059), salinity와 DOC의 상관관계는 연안에서 뚜렷하게 나타나 육상기원의 영향을 확인하였다 (연안 R2=0.6306, 외양 R2=0.1447). 이러한 결과 2009년과 2011년은 연안에서 육상기원과 자생기원의 복합적인 작용이 DOC의 분포에 영향을 준 것이라고 판단된다. 2010년은 외양에서 연안보다 높은 DOC 분포가 나타났다 (연안 평균: 145.5μM, 외양 평균: 153.2μM). 외양에서 Chl a와 DOC의 패턴이 유사하게 나타났으며, 상관관계는 외양에서 뚜렷하게 나타나(연안 R2=0.1053, 외양 R2=0.7752) 자생기원이 DOC의 분포에 영향을 준 것이라고 판단된다.

In order to understand the carbon cycle in the East Sea, dissolved organic carbon (DOC) concentrations were measured during three cruises in summer 2009~2011. The sources of DOC at the study area was investigated based on Correlations between salinity (allochthonous source) and Chl a (autochthonous source), CDOM, FDOM. In the surface layer, DOC concentrations ranged from 51.5 to 172.7μM (ave: 111.1μM), 126.1 to 192.4μM (ave: 149.7μM), and 74.2~129.7μM (ave: 87.2μM) in August 2009, August 2010 and July 2011, respectively. The maximum DOC concentration was measured in the study area in August 2010. In 2009 and 2011, the distribution of DOC concentrations appeared higher in the coastal area than offshore area. The average concentration of DOC in 2009 for coastal area was 121μM, while for offshore area was 106.6μM. In 2011, the average concentration of DOC for coastal area was 121μM, while for offshore area was 106.6μM. High concentration patterns of FDOM and Chl a, and low concentration pattern of salinity were observed in the coastal area in 2009 and 2011. Both 2009 and 2011 showed the correlation between FDOM and Chl a were clearly influenced by autochthonous source (coastal area R2=0.8920, offshore area R2=0.2541 and coastal area R2=0.7793, offshore area R2=0.5059 for 2009 and 2011, respectively). The relationship of FDOM and salinity in 2009 was influenced by allochthonous source (coastal area R2=0.7978, offshore area R2=0.3720) and the relationship of salinity and DOC in 2011 was also influenced by allochthonous source (coastal area R2=0.6306, offshore area R2=0.1447). As a result, in 2009 and 2011, the distribution of DOC was influenced by both allochthonous source and autochthonous source. The distribution pattern of DOC concentrations in 2010 was different from the one in 2009 and 2011. In Summer at 2010, DOC concentrations were found to be higher at offshore area compared to the one in coastal area (coastal areaave: 145.5μM, offshore areaave: 153.2μM). Similar distribution patterns of Chl a and DOC were observed in the offshore area with a clear correlation between both (coastal R2=0.1053, offshore R2=0.7752). Distribution of DOC showed to be influenced by autochthonous source in 2010 for offshore area.