Ocean and Polar Research

Korea Institute of Ocean Science & Technology (한국해양과학기술원)
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The Characteristics of Physical Oceanographic Environments and Bottom Currents in the KODOS Study Area of the Northeastern Tropical Pacific

동태평양 KODOS 탐사해역에서의 물리해양환경 및 저층해류 특성

  • Shin, Hong-Ryeol (Department of Atmospheric Science, Kongju National University) ;
  • Hwang, Sang-Chul (Ocean Climate and Environment Research Division, KORDI) ;
  • Jeon, Dong-Chull (Ocean Climate and Environment Research Division, KORDI) ;
  • Kim, Ki-Hyune (Marine Geoenvironment and Resources Research Division, KORDI) ;
  • Kwak, Chong-Heum (Department of Atmospheric Science, Kongju National University) ;
  • So, Seun-Seup (Department of Atmospheric Science, Kongju National University)
  • 심홍렬 (공주대학교 자연과학대학 대기과학과) ;
  • 황상철 (한국해양연구원 해양기후.환경연구본부) ;
  • 전동철 (한국해양연구원 해양기후.환경연구본부) ;
  • 김기현 (한국해양연구원 해저환경.자원연구본부) ;
  • 곽종흠 (공주대학교 자연과학대학 대기과학과) ;
  • 소선섭 (공주대학교 자연과학대학 대기과학과)
  • Received : 2004.04.27
  • Accepted : 2004.06.09
  • Published : 2004.06.30
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Abstract

Hyrdography and deep currents were measured from 1997 to 1999 to investigate deep-sea environments in the KODOS (Korea Deep Ocean Study) area of the northeastern tropical Pacific. KODOS area is located meridionally from the North Equatorial Current to the boundary between the North Equatorial Current and the Equatorial Counter Current. Strong thermocline exists between 10 m and 120 m depths at the study area. Since that strong thermocline does hardly allow vertical mixing between surface and lower layer waters, vertical distributions of temperature, salinity, dissolved oxygen and nutrients drastically change near the thermocline. Salinity-minimum layer, which indicate the North Pacific Intermediate Water (NPIW) and the Antartic Intermediate Water (AAIW), vertically occupies vertically at the depths from 500 m down to 1400 m. The NPIW and the AAIW horizontally occur to the north and to the south of $7^{\circ}N$, respectively. The near-bottom water shows the physical characteristics of $1.05^{\circ}C$ and 34.70 psu at the depths of 10 m to 110 m above the bottom (approximately 4000-5000 m), which was originated from the Antarctic Circumpolar Water. It flows northeastwards for 2 to 4 months at the study area, and its mean velocity was 3.1-3.7 cm/s. Meanwhile, reverse (southwestward) currents appear for about 15 days with the average of 1.0-6.1 cm/s every 1 to 6 months. Dominant direction of the bottom currents obtained from the data for more than 6 months is northeastward with the average speeds of 1.7-2.1 cm/s. Therefore, it seems that deep waters from the Antarctica flow northwards passing through the KODOS area in the northeastern tropical Pacific.

Keywords

Acknowledgement

Grant : 심해저광물자원 개발사업

Supported by : 해양수산부

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