| 저자(한글) |
Jang, Yang-Hee,Khim, Boo-Keun,Shin, Hyoung-Chul,Sigman, Daniel M.,Wang, Yi,Hong, Chang-Su |
| 저자(영문) |
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| 소속기관 |
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| 소속기관(영문) |
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| 출판인 |
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| 간행물 번호 |
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| 발행연도 |
2008-01-01 |
| 초록 |
Seawater samples were collected at discrete depths from five stations across the polar front in the Drake Passage (Antarctic Ocean) by the $20^{th}$ Korea Antarctic Research Program in December, 2006. Nitrate concentrations of seawater increase with depth within the photic zone above the depth of Upper Circumpolar Deep Water (UCDW). In contrast, ${ delta}^{15}N$ values of seawater nitrate decrease with depth, showing a mirror image to the nitrate variation. Such a distinct vertical variation is mainly attributed to the degree of nitrate assimilation by phytoplankton as well as organic matter degradation of sinking particles within the surface layer. The preferential $^{14}{NO_3}^-$ assimilation by the phytoplankton causes $^{15}{NO_3}^-$ concentration to become high in a closedsystem surface-water environment during the primary production, whereas more $^{14}{NO_3}^-$ is added to the seawater during the degradation of sinking organic particles. The water-mass mixing seems to play an important role in the alteration of ${ delta}^{15}N$ values in the deep layer below the UCDW. Across the polar front, nitrate concentrations of surface seawater decrease and corresponding ${ delta}^{15}N$ values increase northward, which is likely due to the degree of nitrate utilization during the primary production. Based on the Rayleigh model, the calculated ${ varepsilon}$ (isotope effect of nitrate uptake) values between 4.0%o and 5.8%o were validated by the previously reported data, although the preformed ${ delta}^{15}{{NO_3}^-}_{initial}$ value of UCDW is important in the calculation of ${ varepsilon}$ values. |
| 원문URL |
http://click.ndsl.kr/servlet/OpenAPIDetailView?keyValue=03553784&target=NART&cn=JAKO200809651047926 |
| 첨부파일 |
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