https://repository.kopri.re.kr/handle/201206/5064 2026-04-20T22:57:06Z 2026-04-20T22:57:06Z Ohneiser, Christian Yoo, Kyu-Cheul Albot, Olga Cortese, Guiseppe Riesselman, Christina Lee, Jae Il McKay, Rob Bollen, Michael Lee, Min Kyung Moon, Heung Soo Kim, Sung-Han Beltran, Catherine Levy, Richard Wilson, Gary S. https://repository.kopri.re.kr/handle/201206/10546 2022-03-24T07:14:33Z 2019-05-01T00:00:00Z

Title: Magneto-biostratigraphic age models for Pleistocene sedimentary records from the Ross Sea Authors: Ohneiser, Christian; Yoo, Kyu-Cheul; Albot, Olga; Cortese, Guiseppe; Riesselman, Christina; Lee, Jae Il; McKay, Rob; Bollen, Michael; Lee, Min Kyung; Moon, Heung Soo; Kim, Sung-Han; Beltran, Catherine; Levy, Richard; Wilson, Gary S. Abstract: The Ross Sea is one of the major sites of formation for Antarctic Bottom Water (AABW), a key component of the global ocean overturning circulation. However, there is currently a lack of high quality stratigraphic records documenting how this water mass flows from the continental shelf into the abyssal ocean, and specifically how this pathway is affected by changes in ice sheet cover on the Ross Sea continental shelf through Pleistocene glacial-interglacial cycles. Over the course of two expeditions in 2015 and 2016, a suite of cores from the upper continental slope to the abyssal plain was obtained by the Korea Polar Research Institute from the R/V Araon. The age of these cores ranges from Holocene to the latest Pliocene, and they hold the potential to document a source-to-sink record of AABW transfer into the abyssal Pacific Ocean. The cores are located in regions with distinct differences in bottom water energy, with high-energy cascading water masses on the upper slope creating the potential for erosional hiatuses, passing downslope into a lower energy setting. To decipher the complex environmental records and allow core-to-core correlation, robust chronostratigraphies are essential. Here, we present age models for four of these cores, based on correlation between their magnetostratigraphy and the geomagnetic polarity timescale, resulting in sedimentation rates between 1.5 cm/ky and 0.5 cm/ky. Rock magnetic data indicate the remanence is carried by magnetite with an almost ubiquitous contribution of high coercivity fraction that is not demagnetised by 100 mT. We demonstrate that a reliable magnetostratigraphy is established for each of these cores, and magnetic properties can be used to identify potential hiatuses in the cores and as a proxy for sedimentary grain-size.

2019-05-01T00:00:00Z Yoon, Joo-Eun Kim, Il-Nam Kim, Kitae Park, Jisoo Kim, Seong-Su Kim, Soyeon Lee, Jiyoung Jung, Jinyoung Lee, Min Kyung Lee, Jae Il Kim, Hyun-cheol Yang, Eun Jin Park, Ki-Tae Yoon, Ho Il Macdonald, Alison M. Yoo, Kyu-Cheul https://repository.kopri.re.kr/handle/201206/10510 2022-03-24T07:14:20Z 2018-10-01T00:00:00Z

Title: Ocean iron fertilization experiments - past, present, and future looking to a future Korean Iron Fertilization Experiment in the Southern Ocean (KIFES) project Authors: Yoon, Joo-Eun; Kim, Il-Nam; Kim, Kitae; Park, Jisoo; Kim, Seong-Su; Kim, Soyeon; Lee, Jiyoung; Jung, Jinyoung; Lee, Min Kyung; Lee, Jae Il; Kim, Hyun-cheol; Yang, Eun Jin; Park, Ki-Tae; Yoon, Ho Il; Macdonald, Alison M.; Yoo, Kyu-Cheul Abstract: Since the start of the industrial revolution, human activities have caused a rapid increase in atmospheric CO2 concentrations, which have, in turn, had an impact on climate leading to global warming and ocean acidification. Various approaches have been proposed to reduce atmospheric CO2. The 'Martin (or Iron) Hypothesis' suggests that ocean iron fertilization (OIF) could be an effective method for stimulating oceanic carbon sequestration through the biological pump in iron-limited, high-nutrient, low-chlorophyll (HNLC) regions. To test the Martin hypothesis, 13 artificial OIF (aOIF) experiments have been performed since 1990 in HNLC regions. These aOIF field experiments have demonstrated that primary production can be significantly enhanced by the artificial addition of iron. However, except in the Southern Ocean European Iron Fertilization Experiment, no significant change in the effectiveness of aOIF (i.e., the amount of iron-induced carbon export flux below the winter mixed layer depth) has been detected. These results, including possible side effects, have been debated amongst those who support and oppose aOIF experimentation, and many questions such as effectiveness of scientific aOIF, environmental side effects, and international aOIF law frameworks remain. In the context of increasing global and political concerns associated with climate change, it is valuable to examine the validity and usefulness of the aOIF experiments. Furthermore, it is logical to carry out such experiments because they allow one to study how plankton-based ecosystems work by providing insight into mechanisms operating in real time and under in situ conditions. To maximize the effectiveness of aOIF experiments under international aOIF regulations in the future, thus we suggest a design that incorporates several components. (1) Experiments conducted in the center of an eddy structure when grazing pressure is low and silicate levels are high (e.g., in the Southern Ocean south of polar front during early summer). (2) Shipboard observations extending over a minimum of ~40 days, with multiple iron injections (at least 2 (or 3) iron infusions of ~2,000 kg with an interval of ~10？15 days to fertilize a patch of 300 km2 and obtain a ~2 nM concentration). (3) Tracing of the iron fertilized patch using both physical (e.g., a drifting buoy) and biogeochemical (e.g., sulfur hexafluoride, photosynthetic quantum efficiency, and partial pressure of CO2) tracers. (4) Employment of neutrally buoyant sediment traps and application of the water-column derived 234Thorium method at two depths (i.e., just below the in situ mixed layer depth and at the winter mixed layer depth), with autonomous profilers equipped with an underwater video profiler and a transmissometer. (5) Monitoring of side effects on marine/ocean ecosystems, including production of climate-relevant gases (e.g., N2O, dimethyl sulfide, and halogenated volatile organic compounds), decline in oxygen inventory, and development of toxic algae blooms, with optical sensor equipped autonomous moored profilers and/or autonomous benthic vehicles. Lastly, we introduce the scientific aOIF experimental design guidelines for a future Korean Iron Fertilization Experiment in the Southern Ocean.

2018-10-01T00:00:00Z Kim, JinWook https://repository.kopri.re.kr/handle/201206/9083 2022-03-24T07:14:34Z 2017-07-20T00:00:00Z

Title: The study of biogeochemical behavior of iron in low temperature environments Authors: Kim, JinWook

2017-07-20T00:00:00Z Kim, Il-Nam https://repository.kopri.re.kr/handle/201206/9104 2022-03-24T07:14:21Z 2017-07-20T00:00:00Z

Title: Investigation of variation in oceanic N2O production by iron fertilization experiment Authors: Kim, Il-Nam

2017-07-20T00:00:00Z