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1970년대 이후 남극 로스해 대륙붕에서 수행되어온 탄성파 탐사 및 심부퇴적물 시추를 통해 남극대륙빙상의 발달이 시작된 에오세-올리고세 경계(~34 Ma) 이후의 주요 탄성파 경계면(RSU)과 층서가 규정되었다. 하지만 중기 마이오세(~15.5 Ma) 이후 남극빙상의 반복된 진출과 후퇴로 인한 퇴적기록의 단절이 대륙붕에서 관찰되며, 보다 연속적이고 자세한 기록이 보존된 것으로 추정되는 외대륙경계부에 대한 연구는 탄성파탐사자료 및 심부시추자료의 부족으로 인해 많은 연구가 수행되지 않았다. 본 연구에서는 북서부 로스해 외대륙경계부에 위치한 센트럴분지 인근에서 2013년 이후 획득한 다채널탄성파 탐사자료를 분석하고 선행연구결과와 결합하여 중기 마이오세 이후 남극빙상의 발달 및 저층해류의 흐름변화를 유추하고자 한다. 새롭게 획득된 탄성파 탐사자료를 통해 탄성파상과 퇴적형태를 분류하였으며, 남극 탄성파 탐사자료 공유시스템(SDLS)에 등록된 기존 탄성파 탐사자료와 결합하여 주요 탄성파 층서경계면(RSU1~4)를 센트럴 분지의 대륙사면, 대륙대로 연장하고, 고해저지형 복원 및 퇴적층두께 분포도 작성을 수행하였다. 중기 마이오세의 주요탄성파 경계면 RSU4 이후 중력류에 의해 공급되어 형성된 것으로 추정되는 탄성파상과 퇴적구조가 외대륙붕-대륙사면과 센트럴분지를 채운 하부 퇴적층에서 관찰된다. 후기 마이오세를 지나며 퇴적층의 두께가 대륙사면-대륙대를 따라 점차 감소하고, 중-후기 플라이오세(~3.3 Ma) 주요경계면인 RSU2 이후 쐐기형태의 전진퇴적구조가 대륙사면 상부에 발달하였다. 상부대륙사면에 위치한 소규모 분지에서는 중기 마이오세 이후 사면을 따라 흐르는 저층해류에 의해 형성된 것으로 추정되는 등수심 퇴적층(contourite) 형태가 잘 발달하였으며, 센트럴분지의 북부에 위치한 심해의 기반암상부와 경사면에서도 등수심 퇴적층의 발달이 관찰된다. 하지만 RSU2 이후 상부대륙사면의 소규모 분지에서 발달하던 등수심 퇴적층은 중력류에 의해 공급된 퇴적물에 의해 덮여 형성이 중단된 반면, 심해에서는 계속 발달하였다. 복원된 고해저지형과 퇴적층두께 분포도에서는 북서부 로스해 대륙붕단(shelf break)의 전진과 대륙대에서 상부 대륙사면으로의 퇴적중심부 이동양상이 관찰되었다. 탄성파 탐사자료 분석결과를 통해 중기 마이오세(RSU4) 이후 남극빙상이 보다 차갑고 건조한 형태로 진화함에 따라 대륙사면-대륙대로의 중력류에 의한 퇴적물 공급이 감소하였고, 중-후기 플라이오세(RSU2) 이후 대륙붕단까지 진출한 빙상에 의해 대륙사면상부에 전진퇴적구조가 형성된 것으로 추정된다. 대륙사면을 따라 발달한 저층해류의 흐름은 RSU2 이후 상부 대륙사면에서 약화되었으나, 심해에서는 지속적으로 유지되었던 것으로 추정된다.
1Carbon monoxide (CO) and ozone (O<sub>3</sub>) were continuously measured in the marine boundary layer of the East Sea, the Northwestern Pacific, and the Bering Sea onboard R/V Araon in the second halves of July and
September of 2012, as a part of the SHIpborne Pole-to-Pole Observations (SHIPPO) program. Depending on the characteristics of each section of the cruise track, up to 66 ppbv and 17 ppbv of CO and O</sub>3</sub>
variability were observed, respectively. The O</sub>3</sub>/CO ratio suggests that O</sub>3</sub> was dominantly produced by photochemical reactions in the troposphere, although in the northern sections of the cruise track, the ratio likely suggests vertical transport from the free troposphere or the lowermost stratosphere. To analyze the source characteristics and the transport of both trace gases, a tagging technique in a 3-D
global chemical transport model (Model for OZone And Related chemical Tracers-4; MOZART-4) was applied. The model reproduced the observations fairly well, and the technique enabled us to characterize
the source regions and composition of the observed CO. Anthropogenic emissions from Northeastern Asian countries appeared to be substantial sources of the CO in the southern sections, and biomass
burning in Siberia was an important source of the CO observed in the northern sections of the cruise track. Long-range transport of anthropogenic CO emissions was distinct over the Bering Sea, where the
comparable contributions from North America, Northeast Asia, and Europe were identified. Low CO events driven by southern hemispheric invasion were encountered at the southern coast of the Korean
peninsula and in the North Pacific at ~50N latitude. The model pointed to a noticeable contribution from the open ocean in the Southern Hemisphere for these events.
2007년과 2012년 여름, 북극해의 척치해 부근에서 해빙의 급속한 후퇴가 관측되었다. 이러한 후퇴의 원인은 대기외력의 열역학적인 역할, 고위도 해역에서의 온난화로 인한 융빙, 해수 표층의 태양복사열 증대 및 태평양과 대서양으로부터 유입된 해양 열에너지의 영향 등으로 파악되고 있다 (Polyakov et al., 2012). 본 연구에서는 해빙 급속 후퇴 후 북극해 태평양 해역의 해수의 분포 및 변화 양상을 파악하기 위하여 2008년 여름 일본 쇄빙선 미라이호에서 관측한 해수 특성 자료와 2010년부터 2014년까지 극지연구소 쇄빙선 아라온호에서 관측한 해수 특성 자료를 분석하고 비교하였다. 특히 태평양 여름수의 수평적인 분포는 해빙 급속 후퇴 후 척치해역 내에서의 해양 열염 이동을 이해하는데 큰 역할을 한다. 또한 북부 척치해에서의 수온의 연간 수직 자료를 분석하여 해빙 급속 후퇴 전후의 수직구조의 변화 및 복원을 조사하였다. 그 결과 수심 100m보다 깊은 중층의 수온 아노말리가 해빙 후퇴 전후가 뚜렷하게 반대로 나타났으며 수심 100m보다 얕은 표층에서는 중층 구조와 다른 경향을 보였다. 이는 북부 척치해에서 바람, 해빙움직임 및 해수 순환에 대한 태평양 여름수와 태평양 겨울수의 반응이 서로 다르다는 것을 나타낸다. 마지막으로 2008년과 2012년 해수 특성의 분포 비교를 통해 두 해빙 급속 후퇴 시기의 해양의 열역학적 역할에 대해서도 논의될 것이다.
2008년 AMEX 1 (ARK23/3) 탐사프로그램에 이어 2014년 여름 독일 AWI 극지·해양연구소 쇄빙선 「폴라스턴」을 이용하여 북부 그린란드에서 랍테프 해 방향으로 가로지르며 유라시아 분지와 아메라시안 분지로 나누고 있는 로모노소프 해령을 따라 북극점을 포함한 중앙해역 해역에서 제 28/4차 북극해 ALEX-2014 탐사(ARK-28/4)를 약 10주간 수행하였다. 총 10개국 45명이 참가한 ALEX-2014 (PS87) 탐사목적은 알파해령(Alpha Ridge)과 로모노소프해령(Lomonosov Ridge)에서 북극해 진화역사를 이해하는데 결층으로 남아있는 신생대 고기층과 플라이스토세 퇴적층을 시추하기 위하여 심부 및 천부탄성파탐사 및 Hydrosweep 시스템을 이용하여 정밀한 해저지형탐사를 수행하였다. 또한 Hydrosweep 자료와 함께 Parasound 자료를 이용하여 선정한 시추정점에서 자이언츠박스코어(GKG), 멀티코어(MUC), 중력코어(SL) 및 자이언츠시추코어(KAL) 장비를 이용하여 로모노소프 해령과 마카로프 분지(Makarov Basin)에서 약 20여점의 퇴적물 코어를 시추하였다. ALEX-2014 (PS87) 탐사의 목적은 북극해 중앙해역인 알파해령과 로모노소프해령을 포함한 마카로프 분지해역에서 심부/천부 탄성파탐사자료를 획득하고 탐사해역에 대한 정확한 해저지형 자료를 획득하는데 있다. 연중 대부분 다년 빙으로 덮인 중앙해역에서 플라이스토세 이전 퇴적층을 획득하여 결층으로 남아있는 북극해의 진화역사를 완성하여 북극해의 해빙 생성 시기와 주변대륙에 형성되었던 빙하성장과 후퇴의 역사를 비롯한 심층수 생성 시기 등 고기후/고해양환경변화의 기록을 정확하게 복원하는데 있다. 특히 북극해 중앙해역에서 시추된 빙·해양 퇴적물 코어를 이용하여 중기 제4기 빙하기-간빙기에 일어난 기후변화 기록을 정밀 복원하여 최근 급격히 해빙감소에 따른 북극해 환경변화를 이해하고 그 원인을 규명하는데 탐사의 목적이 있다. 이를 위하여 퇴적물 코어의 층서를 정립하고 퇴적물에 기록되어 다중 프록시(퇴적물 물성, XRF 코어 스캐닝분석, 유공충 안정동위원소와 유기지화학 분석, IP25 및 와편모 조류, 저서성 유공충 미화석 동정 등)에 대한 정밀 분석이 이루어질 예정이다. 본 발표에서는 ALEX-2014 (PS87) 프로그램에서 수행된 탐사와 선상에서 수행한 퇴적물 코어의 예비결과 및 본 탐사와 관련된 향후 북극해 국제공동시추탐사(IODP) 계획 등을 소개하고자 한다.
2014년 여름 독일 AWI 극지·해양연구소 쇄빙선 「폴라스턴」에 승선하여 북부 그린란드에서부터 러시아의 랍테프 해 방향으로 가로지르며 북극해를 유라시아 분지와 아메라시안 분지로 나누고 있는 로모노소프 해령을 따라 북극점을 포함한 중앙해역 해역에서 제 28/4차 북극해 ALEX-2014 탐사(ARK-28/4)를 약 10주간 수행하였다. 총 10개국 45명이 참가한 ALEX-2014 (PS87) 탐사는 북극해 4대 해령 중 알파해령(Alpha Ridge)과 로모노소프해령(Lomonosov Ridge) 해역에서 심부 및 천부탄성파탐사 및 Hydrosweep 시스템을 이용하여 정밀한 해저지형탐사를 수행하였다. 또한 Hydrosweep 자료와 함께 4 kHz Parasound 자료를 이용하여 선정한 시추정점에서 자이언츠박스코어(GKG), 멀티코어(MUC), 중력코어(SL) 및 자이언츠시추코어 (KAL) 장비를 이용하여 로모노소프 해령과 마카로프 분지(Makarov Basin) 및 아문센 분지(Amundsen Basin)에서 총 80정점에서 퇴적물 코어를 시추하였다. 그중에서 약 20여점의 박스코어와 멀티코어를 이용하여 표층 퇴적물 코어를 획득하였으며 중력코어와 자이언츠시추코어를 이용하여 40여점의 시추코어를 시추하였다.
또한 ALEX-2014 (PS87) 탐사의 주요 목적은 북극해 중앙 결빙해역인 알파해령과 로모노소프 해령을 포함한 마카로프분지와 아문센분지 해역에서 심부/천부 탄성파탐사자료를 획득하고 탐사해역에 대한 정확한 해저지형 자료를 획득하는데 있다. 특히 해양지질탐사의 주요 목적은 연중 대부분 다년 빙으로 덮여있는 북극해 중앙해역에서 중생대 이후 북극해 진화역사를 이해하는데 결층으로 남아있는 제 3기 고기층과 플라이스토세 퇴적층을 획득하여 결층(hiatus)으로 남아있는 북극해의 진화역사를 완성하여 북극해의 해빙 생성 시기와 주변대륙에 형성되었던 빙하성장과 후퇴의 역사를 비롯한 북극해와 북대서양이 열린 이후 형성된 전 지구적인 심층수 생성 시기 등 고기후/고해양환경변화의 기록을 정확하게 복원하는데 있다. 또한 북극해 중앙해역에서 시추된 빙·해양 퇴적물 코어를 이용하여 중기 제4기 빙하기-간빙기에 일어난 기후변화 기록을 정밀 복원하여 최근 급격히 해빙감소에 따른 북극해 환경변화를 이해하고 그 원인을 규명하는데 탐사의 목적이 있다. 이를 위하여 시추된 퇴적물 코어의 층서를 정립하고 퇴적물에 기록되어 다중 프록시(퇴적물 물성, XRF 코어 스캐닝분석, 유공충 안정동위원소와 Nd 및 Mg/Ca분석 및 유기지화학 분석, IP25및 생체지표분석, 와편모 조류 및 저서성 유공충 미화석 동정 등)에 대한 정밀 분석이 이루어질 예정이다. 본 발표에서는 ALEX-2014 (PS87) 프로그램에서 수행된 탐사와 선상에서 수행한 16점의 박스코어 퇴적물과 4점의 KAL 퇴적물 코어를 분석한 예비결과 및 본 탐사와 관련된 향후 북극해 로모노소프 해령에서 수행 될 국제공동시추탐사(IODP) 계획 등을 소개하고자 한다.
A 4.7-m-long sediment core JV10 covering about 4000 years was collected from the Weddell Sea
located near the Joinville Island (63° 15’S, 55° 45’W), the northern tip of the Antarctic Peninsula.
The study area is influenced by both Weddell Sea Transitional Water and Upper Circumpolar
Deep Water, so it can be a good site to study ocean circulation of Southern Ocean. Six AMS
radiocarbon ages were determined by carbonate shells at the CAIS (Center for Applied Isotope
Studies) at the University of Georgia. No age inversions were observed, implying a lack of
reworking during deposition. Sedimentological, geochemical, and micropaleontological parameters
were analyzed to reconstruct paleoenvironmental changes. The core was visually described and
sliced for X-radiographs, and analyzed to determine magnetic susceptibility (MS) and the content
of total organic carbon (TOC) and calcium carbonate (CaCO3) content. Grain size is analyzed at 4
cm interval and diatom assemblage composition and abundance are analyzed at about 2 cm
interval. Long chain alkyl 1,13- and 1,15-diols, specific lipids of diatoms of the genus Proboscia,
are analyzed to test as a new proxy of sea surface temperature (SST). Chemosynthetic Bivalve
shell Calyptogena sp. which is associated with the cold seep occurred at six horizons from ca.
4000 to 2500 yr BP. We postulate that the environment of study area was relatively stable during
this period. It is consistent with the result of the James Ross Island close to the study area. After
2500 yr BP, MS, TOC, diatom abundance changed by about 500-year periodicity. This trend is
being examined in terms of the Antarctic sea ice variability.
A 4.76-m-long sediment core JV10-GC01 covering about 4000 years was collected near
the Joinville Island, which is located on the northern tip of the Antarctic Peninsula. Six AMS
radiocarbon ages were determined by carbonate shells. No age inversions were observed,
implying a lack of reworking during deposition. Sedimentological, geochemical, and micropaleontological
parameters were analyzed to reconstruct paleoenvironmental changes. The
records of total organic carbon, diatom abundance, diatom assemblage suggest that warm,
stratified and stable condition lasted from 3900 to 2500 yr BP. After that, cooling condition
persisted for about 1300 years from 2500 to 1200 yr BP. The onset of Neoglacial in this study
is contemporaneous with James Ross Island, Bransfield Basin, and Maxwell Bay. However,
the periods of Neoglacial, MWP, LIA are different from the Firth of Tay, although two sites
are very close. In this core sediment, about 500 year periodicity of climate cooling is observed
since 3000 yr BP. It may be correlative with 550-yr cyclicities in North Atlantic circulation patterns
during the Holocene.
A bacterium with lipolytic activity was isolated from the Chukchi Sea within the Arctic Ocean. The lipase BpL5 from the isolate, Bacillus pumilus ArcL5, belongs to subfamily 4 of lipase family I. The optimum pH and temperature of the
recombinant enzyme BpL5, as expressed in Escherichia coli, were 9.0 and 20℃, respectively. The enzyme retained 85 % of its activity at 5 ℃. There was a significant difference between temperatures for maximal activity (20℃) and for protein denaturation (approx. 45℃). The enzyme preferred middle-chain
(C8) p-nitrophenyl substrates. Two mutants, S139A
and S139Y, were rationally designed based on the 3D structure
model, and their activities were compared
with that of the wild type. The both mutants showed
significantly improved activity against tricaprylin.
A better understanding of the impact of global change on Southern Ocean ecosystem is one of major science themes of SOOS. The Ross Sea is a good site for monitoring of ongoing ecosystem changes and their effects because it is a particularly productive region of the Southern Ocean system. And the high primary productivity in the Antarctic polynyas reflects the highly variable environmental conditions. The KOPRI Antarctic Research Program of oceanic observation, especially which is focused on the Ross Sea and the Amundsen Sea, is an integration of interdisciplinary studies and is pursuing the multi-level from satellite to ocean floor. The KOPRI biology/ecosystem research group is studying the plankton ecology such as primary production, phytoplankton physiology, abundance, temporal and spatial distribution, dominant species, community structure, grazing impact, and trophic interaction among plankton. We are also planning to process study by using sediment traps as well as experimental observations. KOPRI’s previous activities in the Amundsen Sea will be presented today, and our future plans for long-term ecosystem monitoring in the Ross Sea region are discussed. productive region of the Southern Ocean system. And the high primary productivity in the Antarctic polynyas reflects the highly variable environmental conditions. The KOPRI Antarctic Research Program of oceanic observation, especially which is focused on the Ross Sea and the Amundsen Sea, is an integration of interdisciplinary studies and is pursuing the multi-level from satellite to ocean floor. The KOPRI biology/ecosystem research group is studying the plankton ecology such as primary production, phytoplankton physiology, abundance, temporal and spatial distribution, dominant species, community structure, grazing impact, and trophic interaction among plankton. We are also planning to process study by using sediment traps as well as experimental observations. KOPRI’s previous activities in the Amundsen Sea will be presented today, and our future plans for long-term ecosystem monitoring in the Ross Sea region are discussed.
A continuous series of 60 snow samples was collected at a 2.5-cm interval from a 1.5-m snow
pit at a site on the Styx Glacier Plateau in Victoria Land, Antarctica, during the 2011/2012 austral summer
season. Various chemical components (δD, δ<sup>18</sup>O, Na<sup>+</sup>, K<sup>+</sup>, Mg<sup>2+</sup>, Ca<sup>2+</sup>, Cl<sup>-</sup>, SO<sub>4</sub><sup>2-</sup>, NO<sub>3</sub><sup>-</sup>, F<sup>-</sup>, CH<sub>3</sub>SO<sub>3</sub><sup>-</sup>,CH<sub>3</sub>CO<sub>2</sub><sup>-</sup> and HCO<sub>2</sub><sup>-</sup>) were determined to understand the highly resolved seasonal variations of these
species in the coastal atmosphere near the Antarctic Jang Bogo station. Based on vertical profiles of δ<sup>18</sup>O,
NO<sub>3</sub><sup>-</sup> and MSA, which showed prominent seasonal changes in concentrations, the snow samples were dated
to cover the time period from 2009 austral winter to 2012 austral summer with a mean accumulation rate of
226 kg H<sub>2</sub>O m<sup>-2</sup> yr<sup>-1</sup>. Our snow profiles show pronounced seasonal variations for all the measured chemical
species with a different pattern between different species. The distinctive feature of the occurrence patterns
of the seasonal variations is clearly linked to changes in the relative strength of contributions from various
natural sources (sea salt spray, volcanoes, crust-derived dust, and marine biogenic activities) during different
short-term periods. The results allow us to understand the transport pathways and input mechanisms for
each species and provide valuable information that will be useful for investigating long-term (decades to
century scale periods) climate and environmental changes that can be deduced from an ice core to be
retrieved from the Styx Glacier Plateau in the near future.
A data set containing sea surface skin and bulk temperature, measured simultaneously at same location in Pacific during 2010, 2011, 2012 using trasits of icebreaker Araon and difference are assessed to evaluate the implications of temperature difference to satellite remote sensing. Skin temperature(Ts) at depth 0m and bulk temperature(Tb) at depth 7m are observed using methods that coupled temperature(T) must share spationtemporally and have explicitly overall evaluation errors of deference(△) wwhich were presented by in terms of standard deviation(SD), standard error(SE), and error of smmpling(ES) of in situe daa. Experimental results show T△ can be discussed that Tb is warmer △T average fo 0.986K within the accuracy of ±0.78K SD and ±0.01K SE in ca of ±2.18% ES within the confidence interval of 95% than Ts durin spring, summer and fall in Pacific and Southern Ocean.
A denitrifying bacterium, Paracoccus marcusii PAMC 22219, was isolated from Arctic marine sediment in Svalbard, Norway. The obtained contigs were 265 with genome size of 4.0 Mb and G + C content of 66.1%.
This bacterial genome revealed that it had nitrate and nitrite ammonification genes involved in the denitrification process, suggesting that P.marcusii PAMC 22219 is a denitrifying bacterium. This is the first genome that has been
sequenced in the genus Paracoccus, isolated from an Arctic environment.
A detailed palynological investigation of the almost continuous middle through upper Miocene sediment sequence of ODP Hole 907A in the Iceland Sea revealed the presence of a new species of the dinoflagellate cyst
genus Batiacasphaera, and a new species of the acritarch genus Lavradosphaera. Batiacasphaera bergenensis sp.nov. and Lavradosphaera elongata sp. nov. are both morphologically distinctive and have well-defined stratigraphic
range tops that are independently constrained by the pristine paleomagnetic record of Hole 907A. Both species disappeared within a narrow interval across the middle to late Miocene boundary, when smallscale
glaciations on Greenland were large enough to reach sea level. The distinct morphology of the proposed species and their highest occurrence in this critical interval highlights their potential for future biostratigraphic
application in the Miocene of the high northern latitudes, an area important for understanding the Late Cenozoic transition into a bipolar glaciated world.
A Gram-negative, rod-shaped, red-pink in color, and UV radiation-resistant bacterium Hymenobacter sp. strain PAMC26554 was isolated from Usnea sp., an Antarctic lichen, and belongs to the class of Cytophagia and the phylum of Bacteroidetes. The complete genome of Hymenobacter sp. PAMC26554 consists of one chromosome (5,244,843 bp) with two plasmids (199,990 bp and 6421 bp). The genomic sequence indicates that Hymenobacter sp. strain PAMC26554 possesses several genes involved in the nucleotide excision repair pathway that protects damaged DNA. This complete genome information will help us to understand its adaptation and novel survival strategy in the Antarctic extreme cold environment.
A Gram-stain-negative, facultatively aerobic, cream-coloured, ovoid-shaped, non-motile and psychrotolerant bacterial strain, PAMC 27389<sup>T</sup>, was isolated from terrestrial soil collected on King George Island, Antarctica. Phylogenetic analysis based on the 16S rRNA gene sequence
revealed that strain PAMC 27389<sup>T</sup> belongs to the genus Pseudorhodobacter, sharing highest
similarities with the type strains of Pseudorhodobacter wandonensis (96.9 %),
Pseudorhodobacter antarcticus (96.8 %), Pseudorhodobacter ferrugineus (96.5 %) and
Pseudorhodobacter aquimaris (95.4 %). Average nucleotide identity values between strain
PAMC <sup>T</sup> and the type strains of P. wandonensis, P. antarcticus, P. ferrugineus and
P. aquimaris were 70.8, 70.9, 71.0 and 70.5 %, respectively and the genome-to-genome
distances were 18.4 - 19.1 %, indicating PAMC 27389T is clearly distinguished from the most
closely related Pseudorhodobacter species. The genomic DNA G+C content was 60.1 mol%.
Strain PAMC <sup>T</sup> grew at 0 - 37 8C (optimally at 15 - 20 8C), at pH 5.5 - 9.0 (optimally at
pH 6.5 - 7.0) and in the presence of 0.5 - 3.0 % (w/v) sea salt (optimally with 0.5 %). It lacked
bacteriochlorophyll a. The major fatty acids (.5 %) were summed feature 8 (C18 : 1v7c and/or
C18 : 1v6c) and C18 : 1v7c 11-methyl. The major polar lipids were phosphatidylcholine,
phosphatidylglycerol, an unidentified phospholipid, an unidentified aminolipid, an unidentified
lipid and three unidentified aminophospholipids. The major respiratory quinone was Q-10.
Based on the phenotypic, chemotaxonomic and genomic data presented, we propose the name
Pseudorhodobacter psychrotolerans sp. nov. with the type strain PAMC 27389<sup>T</sup> (=KCTC42640<sup>T</sup>=JCM 30764<sup>T</sup>)
A Gram-stain-negative, rod-shaped and motile strain, designated PAMC 27536<sup>T</sup>, was isolated from deep-sea sediment in the East Sea, Korea. Analysis of the 16S rRNA gene sequence of the strain showed an affiliation with the genus Marinobacterium. Phylogenetic analyses revealed that strain PAMC 27536<sup>T</sup> was most closely related to the type strain of Marinobacterium rhizophilum CL-YJ9<sup>T</sup> with a 16S rRNA gene sequence similarity of 98.5 % and to other members of the genus Marinobacterium (94.0-91.7 %). Genomic relatedness analyses between strain PAMC 27536<sup>T</sup> and M. rhizophilum KCCM 42386T resulted in the average nucleotide identity of 85.6% and the estimated DNA-DNA hybridization of 24.6 % by the genome-to-genome distance calculator, indicating that they represent genomically distinct species. Cells of strain PAMC 27536<sup>T</sup> grew optimally at 25-30 ℃ and pH 7.0-7.5 in the presence of 3 % (w/v) sea salts. The major cellular fatty acids were C16:1 ω6c and/or C16:1 ω7c (42.7 %), C18:1 ω6c and/or C18:1 ω7c (20.9 %) and C16:0 (19.1 %). The major isoprenoid quinone was Q-8. The genomic DNA G+C content was 56.1-57.2 mol%. Based on the phylogenetic, chemotaxonomic, genomic and phenotypic data presented, we propose the name Marinobacterium profundum sp. nov. with the type strain PAMC 27536<sup>T</sup> (= KCCM 43095<sup>T</sup> = JCM 30410<sup>T</sup>).
A Gram-staining-negative, motile, aerobic and rod-shaped bacterial strain, PAMC 27157<sup>T</sup>, was isolated from a melt pond on sea ice in the Chukchi Sea. Phylogenetic analysis of the 16S rRNA gene sequence of strain PAMC 27157<sup>T</sup> revealed an affiliation to the genus Aureimonas with the closest sequence similarity (96.2 %) to that of Aureimonas phyllosphaerae. Strain PAMC 27157<sup>T</sup> grew optimally at 30°C and pH 7.0 in the presence of 3.5 % (w/v) NaCl. The major polar lipids were diphosphatidylglycerol, phosphatidylglycerol, phosphatidylethanolamine,phosphatidylcholine, phosphatidylmonomethylethanolamine, sulfoquinovosyldiacylglycerol and an unidentified aminolipid. The major cellular fatty acid was summed feature 8 (C<sub>18</sub> : <sub>1</sub>ω7c and/or C<sub>18</sub> : <sub>1</sub>ω6c, 83.1 %) and the major respiratory quinone was Q-10. The genomic DNA G+C content was 69.1 mol%. The combined phylogenetic, phenotypic and chemotaxonomic data showed that strain PAMC 27157<sup>T</sup> could be clearly distinguished from species of the genus Aureimonas with validly published names. Thus, strain PAMC 27157<sup>T</sup> should be classified as representing a novel species in the genus Aureimonas, for which the name Aureimonas glaciistagni sp. nov. is proposed. The type strain is PAMC 27157<sup>T</sup> (=KCCM 43049<sup>T</sup> =JCM 30183<sup>T</sup>).
A Gram-staining-negative, rod-shaped and non-motile strain, designated PAMC 27266<sup>T</sup> , was isolated from deep-sea sediment of the Arctic Ocean. Analysis of the 16S rRNA gene sequence of strain PAMC 27266<sup>T</sup> showed the closest affiliation with the genus Sediminicola. Phylogenetic analyses revealed that strain PAMC 27266<sup>T</sup> formed a robust clade with Sediminicola lutes NBRC 100966T with the 16S rRNA gene sequence similarity of 98.9%. Genomic relatedness analyses based on the average nucleotide identity and the genome-to-genome distance showed that strain PAMC 27266T is clearly distinguished from S. lutes NBRC 100966<sup>T</sup>. Cells of strain PAMC 27266<sup>T</sup> grew optimally at 15℃ and pH 6.5-7.5 in the presence of 3.5% (w/v) sea salts. The major polar lipids were phosphatidylethanolamine, two unidentified aminophospholipids and two unidentified lipids. The only respiratory quinone was menaquinone-6. The major cellular fatty acids (> 10%) were C16 : 1 ω6c and/or C16 : 1ω7c and C15 : 0. The genomic DNA G+C content was 37.9 mol%. Based on the phylogenetic, genomic, chemotaxonomic and phenotypic data presented, we propose a new species for strain PAMC 27266T (= KCCM 43038<sup>T</sup> = JCM 19894<sup>T</sup>) with the name Sediminicola arcticus sp. nov.
A High-resolution lithological and isotope-geochemical results of a well age constrained sediment core was raised from the northeastern Japan (East) Sea recording 10 dark layers (DL) over the last 40 ka BP. Pollen analysis of the core allows us to reconstruct the history of surrounding landmass vegetation and to determine pronounced vegetation/climate changes. We found that DL 10 correlated with a DO/Chinese interstadial 8 was forced by increased East Asian humidity and influx of the nutrient-rich water into the sea. DL5 formed during cold the Heinrich event 3 (HE), 30-31 ka BP, was most likely to be initiated by the global sea level descent and reduction of seawater exchange with the North Pacific. High resolution of δ<sup>18</sup>O<sub>pf</sub> records reflect a unique sensitivity of the Japan (East) Sea to input of the North Pacific water through the shallow Tsushima and Tsugaru Straits. This led us to the important evidence of the eustatic-sea level changes during the last 40 ka BP. Since 29 ka BP, δ<sup>18</sup>O<sub>pf</sub> curve shows a continuous descending sea level interrupted by sharp drops of HE 2 at time with a following rise of DO interstadial 2. A sharp δ<sup>18</sup>O<sub>pf</sub> increase since 18.6 ka BP is consistent with coral results which indicate abrupt termination of LGM lowstand by a rapid sea level rise initiated at 19.0 ka BP.
A long-term change in weather extremes seemingly occurs along the change of global/regional mean temperatures. Thus far, this notion is grounded by statistical records of occurrences of weather extremes alone. This study investigates the global changes of the extreme cold anomaly (ECA) with three different aspects, as presented by the so-called Markovian climate descriptors such as recurrence time, persistence, and entropy (or irregularity). Here the ECA is defined as the bottom two percentile of deseasonalized daily surface temperature records for each 2.5°-grid of NCEP/NCAR reanalysis I data for the period of 1951-2010. By the definition, the threshold of temperature for ECA turns out to be 0°C (for the tropical region) to -20°C (for the polar region). As results, the ECA is found to have experienced the increase in recurrence time (25 days per decade), the decrease in persistence (？0.15 days per decade), and the decrease in entropy (？0.01 per decade). These trends indicate that the ECA has occurred less frequently and more regularly, and lasted shorter. These changes have been more rapid over East and Southeast Asia, while the opposite changes are shown over the area around 30°S (i.e., Australia, South Africa, and the center of South America). Time series of the Markovian climate descriptors for each region demonstrate that the regional ECAs do vary on the decadal timescale. To ensure our results, the same analyses are carried out with two additional data: ERA-interim reanalysis data (1979？2010) and Hadley Centre quality-controlled gridded station data (HadGHCND) (1951？2010). The trends of the descriptors from the two additional data are similar to those from the NCEP/NCAR reanalysis data in North America. In the other regions, the time variations in the descriptors during the 2000s (1980s and 1990s) from ERA-interim reanalysis data agree (disagree) with those from the NCEP/NCAR reanalysis data. The present study suggests that the Markovian climate descriptors would serve to systematically cover important characteristics of the changes of weather extremes, which cannot be revealed by a single parameter like the frequency.
A minor stratospheric sudden warming (SSW) event was noticed in the southern hemisphere (SH) during September (day259) 2010 along with two episodic warmings in early August (day212) and late October
(day 300) 2010. Among the three warming events, the signature of mesosphere response was detected only for the September event in the mesospheric wind dataset from both meteor radar and MF radar
located at King Sejong Station (62°S, 59°W) and Rothera (68°S, 68°W), Antarctica, respectively. The zonal winds in the mesosphere reversed approximately a week before the September SSW event, as has been
observed in the 2002 major SSW. Signatures of mesospheric cooling (MC) in association with strato-spheric warmings are found in temperatures measured by the Microwave Limb Sounder (MLS). Simu-
lations of specified dynamics version of Whole Atmosphere Community Climate Model (SD-WACCM) are able to reproduce these observed features. The mesospheric wind field was found to differ significantly
from that of normal years probably due to enhanced planetary wave (PW) activity before the SSW. From the wavelet analysis of wind data of both stations, we find that strong 14？16day PWs prevailed prior to
the SSW and disappeared suddenly after the SSW in the mesosphere. Our study provides evidence that minor SSWs in SH can result insignificant effects on the mesospheric dynamics as in the northern
A new fatty acid ester disaccharide, 2-O-(β-Dglucopyranosyl)-
(1), a new ascorbic acid derivative, 2-caffeoyl-3-
ketohexulofuranosonic acid γ-lactone (2), and a new iridoid
glycoside, 10-dimethoxyfermiloside (3), were isolated along with
13 known compounds (4？16) from fermented noni fruit juice
(Morinda citrifolia). The structures of the new compounds,
together with 4 and 5, were determined by 1D and 2D NMR
experiments, as well as comparison with published values.
Compounds 2 and 7 showed moderate inhibitory activities in a
TNF-α-induced NF-κB assay, and compounds 4 and 6 exhibited
considerable quinone reductase-1 (QR1) inducing effects.
A new investigation of paleoclimate and environmental changes using beryllium isotopes in sediment from the Mendeleev Ridge of the western Arctic Ocean was accomplished using a 39 cm-long box core record. The age of core PS72/396-3 appears to date back to MIS 5.d based on the stratigraphy of beryllium isotopes and paleomagnetic data and other isotopic data of this study, AMS <sup>14</sup>C ages and oxygen and carbon isotopes of
planktonic foraminifera N. pachyderma sin. Both authigenic <sup>10</sup>Be and <sup>9</sup>Be records show that there are three major cold periods during MIS 5.d and reveals a much longer warm period after the second cold period based on <sup>9</sup>Be record. The <sup>10</sup>Be stratigraphy also reveals a paleomagetic excursion at 45 kyr which is comparable to other records. At depths from 22 to 25 cm, the lowest <sup>10</sup>Be signal may be due to the highest paleomagnetic intensity,
which is indicated as an age of 75 kyr from other records. However, a reduction in cosmogenic 10Be could be due to ice cover, and is correlated with δ<sup>10</sup>O evidence fo a cold period. Interestingly, Be data show that constant input of Be to the Mendeleev Ridge is observed for this time period. During this time period, TOC (%) values also show a similar pattern. The record of authigenic Be is inversely correlated to that of Ca and proportional
to opal production. These observations confirm that Be can also be a good proxy as a climatic tracer. This study may be a useful approach for understanding Arctic climate change.
A novel exopolysaccharide (EPS) producing psychrotrophic bacterium Flavobacterium sp. ASB 3-3 was isolated from Arctic glacier soil and identified. The optimum fermentation conditions for EPS production were an initial medium pH of 7.2 and an initial inoculum size of 5% (v/v). The maximum yield of EPS (7.25 ± 0.26 g L-1) was obtained after cultivation at 25 °C for 120 h with glycerol as the sole carbon source. The EPS was purified and its structural characteristics were analyzed by 1H and 13C NMR. The predominant repeating units of this EPS are (α, β) D-glucose and D-galactose and it is different from the structure of EPSs produced by other Arctic and Antarctic bacteria, which have mannose units. In addition, EPS has demonstrated a comparable emulsifying property than SDS and flocculating properties with kaolinite, suggesting their potential applications in various industries. The EPS also significantly improved the tolerance of Flavobacterium sp. and Escherichia coli from freeze？thaw cycles, suggesting that it might be used to survive in polar regions and it can have possible usage as microbial cryoprotectants.
A series of evaporation and deposition, a long-range atmospheric transport, and a cold condensation process is important processes to widespread distribution of Persistent Organic Pollutants(POPs) in remote polar regions. The atmospheric POPs from the source regions could be deposited into the surface snow in Antarctica. However, the data of the snow concentration of POPs are limited than other environmental matrixes. In the present work, we report the concentrations of hexachlorocyclohexanes (HCHs) and hexachlorobenzene (HCB) in the surface snow samples obtained from the East Antarctica between 2011 and 2013. The concentrations of HCHs and HBC in the East Antarctic snow were low compared to those in remote regions of the northern hemisphere. Our previous snow concentrations of POPs from Dome Fuji and Dome A were compared to those od the present studies. Our results indicate that the surface snow in East Antarctica contains low levels of POPs, which could affect Antarctic ecosystem.
A small plasmid (pDK4) from the Antarctic marine organism Pseudoalteromonas sp. PAMC 21150, was purified, sequenced and analyzed. pDK4 was determined to be 3,480 bp in length with a G+C content of 41.64% and contains three open reading frames encoding a replication initiation protein (RepA), a conjugative mobilization protein (Mob) and a hypothetical protein. PCR-amplified pDK4 was cloned in high-copy pUC19 to yield the fusion vector pDOC153. The chloramphenicol resistance gene was inserted into pDOC153 to give an ampicillin and chloramphenicol-resistant, Pseudoalteromonas ？ Escherichia coli shuttle vector (7,216 bp; pDOC155). The TonB-dependent receptor (chi22718_IV ) and exochitinase (chi22718_III ) genes from Arctic marine P. issachenkonii PAMC 22718 were cloned into pDOC155 to produce pDOC158 and pDOC165, respectively. Both vector derivatives were transferred into plasmid-free Pseudoalteromonas sp. PAMC 22137 by the triparental mating method. PCR experiments showed that the genes were stably maintained both in Pseudoalteromonas sp. PAMC 22137 and E. coli DH5α cells, indicating the potential use of pDOC155 as a new gene transfer system into marine Pseudoalteromonas spp.
A strain isolated from seawater samples in the Chuckchi Sea and exhibiting extracellular lipolytic activity was identified using 16S rRNA gene sequence analysis as Psychrobacter sp. ArcL13. The lipolytic enzyme exhibited cold-active properties and high hydrolytic activity toward p-itrophenyl
caprylate (C<sub>8</sub>), p-nitrophenyl decanoate (C<sub>10</sub>), and sunflower oil. Statistical optimization of the medium components was performed to enhance the production of cold-active extracellular lipolytic activity. Glucose, yeast extract (YE), and NaCl were selected as the main efficient nutrient sources.
Fed-batch fermentation using optimized medium with concentrated YE as the main feeding material showed a maximum lipolytic activity of 10.7U=mL, which was a 21-fold increase in production over unoptimized flask culture conditions. The information obtained in the present study could prove
applicable to the production of cold-active lipase on a large scale.
According to the recent observation by NOAA(US National Oceanic and Atmospheric
Administration), 2015 is the warmest year based on global average temperature since 1880. The air temperatures in the Arctic have been rising at almost twice the global average and the extent and thickness of sea ice in the Arctic have declined. And the warming process in the Arctic is accelerating rapidly. These impacts of drastic change in sea ice caused by climate change in the Arctic threaten the eco-system service and biodiversity in the Arctic. This study intends to estimate the economic value on changes in eco-system services and biodiversity of the Arctic caused by climate change. The result of the valuation indicates that the total benefit from improvement of ecosystem in the Arctic ranges from 318.6 billion won to 715.9 billion won per annum. Replication scenarios can be explored into two broad categories in
future studies: scenarios in consideration of conflicts of different stakeholders and scenarios based on wider or narrower definition of biodiversity in the Arctic.
Active halogens play a significant role in Earth’s environmental systems. Especially, iodine species are known to related to perturbation of HOx/NOx cycles, ozone depletion event, formation of CCN(cloud condensation nuclei), controlling the atmospheric oxidizing capacity. However, the mechanism for abiotic generation of iodine compounds is still not clear. Although the reaction processes taking place in ice matrix are greatly different from those in aqueous solution, chemical reactions of halogens in frozen condition have rarely investigated compared to those in water. In this work, we investigated the formation of tri-iodide (I<sub>3</sub><sup>-</sup>) through iodide oxidation in ice phase under UV irradiation ( λ > 300 nm) and dark condition. The oxidative formation of I<sub>3</sub><sup>-</sup> through iodide oxidation, which is very slow in aqueous solution, was significantly accelerated in polycrystalline ice even in the absence of UV irradiation. The following release of gaseous iodine molecule (I<sub>2</sub>) to the atmosphere was also monitored by CRDS (cavity ring-down spectroscopy). We suspect that the highly enhanced oxidation of iodide in ice is owing to the freeze concentration of iodides, protons, and dissolved oxygen in the ice crystal grain boundaries. The outdoor experiments carried out under ambient solar radiation of the Antarctic region (King George Island, 62°13′S 58°47′W, sea level) also confirmed that the generation of I3- via photooxidative process is enhanced when iodide is trapped in ice. The observed authentic redox transformation of iodide in ice phase suggests a previously unknown generation pathway for the considerable release of reactive halogen compounds to the atmosphere consequently influencing O3 and Hg depletion event, perturbation of OHx/NOx cycles, and DMS oxidation to form CCN.