초록 ▼

○ 쇄빙연구선 아라온호를 이용한 아문젠해 종합해양연구 (서남극 온난화 원인과 경향, 기후변화에 따른 생태계와 생지화학순환 변화 연구) 2010/2011 제 1차 현장조사와 2011/2012 제 2차 현장조사에서 획득한 시료와 자료 처리 및 분석, 논문화작업 연중 실시
○ 아문젠해역 수괴 분포와 해류 순환 패턴, 빙해역, 폴리니아, 대륙사면 등 해양환경의 식물플랑크톤 종류, 분포, 생산력, 규산염, 아질산염+잘산염, 암모니아, 인산염 등 기초자료 분석.
○ 광대역 식물플랑크톤 생리활성 (FlRe: Fluorescence I

○ 쇄빙연구선 아라온호를 이용한 아문젠해 종합해양연구 (서남극 온난화 원인과 경향, 기후변화에 따른 생태계와 생지화학순환 변화 연구) 2010/2011 제 1차 현장조사와 2011/2012 제 2차 현장조사에서 획득한 시료와 자료 처리 및 분석, 논문화작업 연중 실시
○ 아문젠해역 수괴 분포와 해류 순환 패턴, 빙해역, 폴리니아, 대륙사면 등 해양환경의 식물플랑크톤 종류, 분포, 생산력, 규산염, 아질산염+잘산염, 암모니아, 인산염 등 기초자료 분석.
○ 광대역 식물플랑크톤 생리활성 (FlRe: Fluorescence Induction and Relaxation), 부유 원생동물 생태적 분포 특성, 증형 동물플랑크톤 분포와 우점종 섭식율 등 자료 분석
○ 해색위성자료의 검보정 자료 (식물플랑크톤 흡광 (aph), 부유물질 흡광 (ass), 용존유기물 흡광(aCDOM), 수심별 광스펙트럼 변화, 해수변 반사도 및 온도 (lnfrared) 자료 분석.
○ 아문젠해 온난화에 따른 생태계 환경변화 및 반응, 탄소순환,생지화학순환 경로 연구.

Abstract ▼

IV. Results
1. Physical Oceanography in the Amundsen Sea
In order to understand the role of CDW in controlling the hydrodynamics and related biochemical processes on the continental shelf of the Amundsen Sea, the shipbome measurements were conducted during the 2010/11 and 2012 expeditions. The

IV. Results
1. Physical Oceanography in the Amundsen Sea
In order to understand the role of CDW in controlling the hydrodynamics and related biochemical processes on the continental shelf of the Amundsen Sea, the shipbome measurements were conducted during the 2010/11 and 2012 expeditions. The overall purposes of physical oceanography are: (1) to identify the temporal and spatial distribution of CDW on the Amundsen shelf; (2) reveal the main forcing that affects the flow rate of CDW onto the Amundsen shelf. CDW shows a seasonal variability in thickness. The thickness in austral summer season is much thicker than that in winter season. And the calculated heat content mirrors the seasonal variation in the thickness of the CDW layer. To investigate the effects of wind and sea ice concentration on the seasonal variation of the CDW's warm layer thickness, a simplified Ekman pumping model was used. The Ekman pumping at the shelf break, where the warm layer is elevated, shows a strong seasonal variation coinciding with the mooring data.
2. The distribution of dissolved carbon and glacial meltwater in the Amundsen Sea
The Amundsen Sea hosts two most productive polynyas among 37 coastal polynyas and experiences the rapid decline of sea ice extent and glacial retreat melting. We investigated the distribution of dissolved carbon species (pCO₂, DIC, TA) and meltwater faction in order to understand the role of the Amundsen Sea
in the carbon cycle and its possible change due to the changing climate. The Surfacr waters in the outer shelf and sea ice zones were slightly oversaturated in CO₂ with pCO₂ of ~ 400 μatm. In contrast, pCO₂ in the polynyas were strikingly low with the minimum of 150 ppm in Februrary, 2012, which is ascribd to the fast removal of CO₂ by phytoplankton synthesis. Circumpolar Deep Water (CDW) exhibited Dissolved Inorganic Carbon (DIC) around 2300 μmol/kg and Winter Water (WW) revealed slightly lower values of 2200 μmol/kg. The surface water exhibited distinctively lower values of 2000 μmol/kg due to net carbon consumption by photosynthesis, often coinciding with SST increase. The DHe distribution along the Amundsen Trough reveals that glacial meltwater from ice shelves spreads throught the seawater on the continental shelf. DHe distributions along the selves suggest that glasial melting is more pronounced at the western side of Dotson and Pine Island ice shelves due to hogher CDW upwelling. In addintion to the spatial variation, it is noteworthy that the meltwater fraction in 2012 decrease by 50% compared with that in 2012.
3. Different phytoplankton physiology in two polynyas of the Amundsen Sea
The phytoplankton physiological parameters were measured by Fluorescence Induction and Relaxation (FIRe) system in the Amundsen Polynya (AP) and Pine Island Polynya (PIP) of the Amundsen Sea (west Antarctic) in late summer (10 February - 10 March), 2012. The FIRe physiological parameters provide an express diagnostics of the effects of environmental factors, including iron limitation, on photosynthetic processes. On-board FIRe measurements showed that the quantum efficiencies of photosynthesis (Fv/Fm) in near-surface phytoplankton were high (Fv/Fm ~ 0.5) in the PIP, but were drastically reduced in the AP(Fv/Fm ~ 0.3). This difference suggests that phytoplankton physiology was severely iron-limited in the AP, but remained iron-replete in the PIP. Short-term iron enrichment experiments in on-deck incubators have confirmed this inference. However, chlorophyll-a concentrations were higher in the central regions of polynyas rather than in the vicinity of sea ice and ice shelves, suggesting that phytoplankton bloom in polynyas is a slowly developing process that is limited by low light availability in this polar region. We also used underway measurements of FIRe physiological parameters and ocean colour data to extrapolate the results of station measurements over the larger areas. These data provided additional evidence that iron limitation is more prevailed In the AP, compared with that in the PIP.
4. Trophic role of microzooplankton in Phaeocystis and diatom dominated waters in the Amundsen Sea, Antarctica
To elucidate the trophic role of microzooplankton In the Phaeocystis antarctica and diatom dominated waters,we investigated microzooplankton biomass, conmmunity structure and their herbivory in the Amundsen Sea during austral summer. Sampling area was covered the three main the Amundsen environments of the open ocean, Sea Ice continental shelf area and polynya. Polynyas are areas of increased phytoplankton biomass, which can be considered as 'hot spots' of biological productivity mice covered seas. During the study periods, phytoplankton conmlUnity was dominated by solitary type Phaeocystis antarctica in the polynya, and by pennate diatom in the open ocean and continental shelf area. Heterotrophic dinoflagellate was the most dominant microzooplankton grazer In the Amundsen Sea, particularly In the polynya. Phytoplankton and microzooplankton biomass were the highest in the polynya and the lowest in the open ocean. Microzooplankton grazing impacts on phytoplankton was relatively high in the polynya compared to open ocean and continental shelf area. In the polynya, microzooplankton grazing rates often equaled or exceeded phytoplankton growth rates. In this study site, microzooplankton grazing rates were extremely high compared to rates reported sunmler and spring 1997 in the Ross Sea polynya. These results show that microzooplankton was grazing more vigorously in the polynya than the open ocean. The high microzooplankton grazing rates on Phaeocystis antarctica suggest that microzooplankton herbivory may be one of the most important loss processes affecting phytoplankton biomass and composition, particularly in the Amundsen Sea polynya.
5. Distribution of mesozooplankton and metabolism of major copepods
We examined the distribution of mesozooplankton, grazing impact on the phytoplankton, and oxygen consumption rate (respiration rate) of major copepods in the Amundsen Sea. Mesozooplankton samples were collected with a Bongo net (330 and 505 ㎛ mesh). A total of 32 mesozooplanktonic taxa were identified, including 10 copepod species and 3 euphausia species. Mesozooplankton followed a latitudinal distribution in relation to hydrographic and environmental features, with copepods dominating in the oceanic area and euphausiids dominating in the polynya. The grazing impact of three copepods (Rhincalanus gigas, Calanoides acutus, and Metridia gerlachei) on phytoplankton was low, with the consumption of 3 % of phytoplankton standing stock and about 4 % of daily primary production. Euphausia crystallorophias consumed 17 % of phytoplankton biomass and 84 % of daily primary production. The respiration rates of major copepods and E. crystallorophias furcilia were detemlined usmg a Clark-type oxygen microsensor with a high temporal resolution. The estimated respiration rates of major copepods and E. crystaliorophias furcilia fell within the range of previously reported values. The respiration rates of the species of relatively large body size were rather low, whereas the smaller species appeared to show higher rates. The difference of respiration rate between the two groups may reflect the length of their life cycle, the timing of reproduction, and their past feeding history. Our findings suggest that this simple microsensor technique can yield reliable data for high resolution analysis of the zooplankton metabolism.
6. Acoustic observation of krill distribution along the ice shelves
Acoustic survey was conducted to understand the variability of krill distribution along two representative ice shelves in the Amundsen Sea: Dotson ice shelf (DIS) and Getz ice shelf (GIS).Acoustic data were collected from surface to 500 m depths usmg a scientific echo sounder (EK60, Simrad) configured with down looking 38, 120, and 200 kHz split beam transducers mounted in the hull of IBRVAraon.Therectangulametwashauledtoobtainthelength frequencydistributionofdo minant species, which can affect the distribution of sound scattering layer. Euphausiacrystallorophias(ice krill) was predominant species and mean body length was 12.4 mm (SD: 5.9 mm) ranged from 4 to 31 mm. In this report, 120 kHz echogram shows the horizontal and vertical variability of acoustic signals between DIS and GIS. Around DIS, the strong sound scattering layer wasmainly detected above 100 m depth, while this was distributed not only above 100 m depth but also below 100-m around GIS. Further study will be investigated to reveal variability of ice krill density associated with different environmental conditions between DIS and GIS.

목차 Contents

• 표지 ... 1
• 제 출 문 ... 2
• 보고서 초록 ... 4
• 요 약 문 ... 5
• SUMMARY ... 12
• CONTTENTS ... 18
• 목 차 ... 19
• 제 1 장 서 론 ... 21
• 제 2 장 국내·외 기술개발 현황 ... 22
• 제 1 절 국내기술개발현황 ... 22
• 제 2 절 국외기술개발현황 ... 22
• 제 3 장 연구개발수행 내용 및 결과 ... 24
• 제 1 절 수층 구조 특성 ... 24
• 제 2 절 아문젠해의 용존 탄소와 빙하용융수 분포 연구 ... 33
• 제 3 절 아문젠해 폴리냐 내 식물플랑크톤 생리 특성 차이 ... 48
• 제 4 절 종속영양 원생동물의 생태 특성 ... 56
• 제 5 절 중형동물플랑크톤 분포와 우점 요각류의 물질대사 ... 63
• 제 6 절 아문젠해 빙붕 부근의 크릴 분포 ... 71
• 제 7 절 위탁연구 수행성과 ... 78
• 제 4 장 연구개발목표 달성도 및 대외기여도 ... 79
• 제 1 절 2단계 연도별 연구목표 ... 79
• 제 2 절 연구개발목표 달성도 (정성적 성과) ... 80
• 제 3 절 주요 정성적 성과 (국제협력분야) ... 80
• 제 5 장 연구개발결과의 활용계획 ... 82
• 제 6 장 연구개발과정에서 수집한 해외과학기술정보 ... 83
• 끝페이지 ... 84