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Papers by Lester Lembke-Jene

Research paper thumbnail of Stationkeeping in Solid Drift Ice

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Research paper thumbnail of AURORA BOREALIS A new European Combined Research Icebreaker and Drilling Vessel

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Research paper thumbnail of Development of New Offshore and Icebreaker Technologies for the European Research Icebreaker Consortium's Research Infrastructure

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Research paper thumbnail of The european research icebreaker AURORA BOREALIS : conceptual design study - summary report = Der europäische Forschungseisbrecher AURORA BOREALIS : Konzeptioneller Schiffsentwurf - Abschlussbericht

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Research paper thumbnail of AURORA BOREALIS - European Research Icebreaker With Drilling Capability

The polar oceans are the least known areas of the globe, in although they hold the key to many of... more The polar oceans are the least known areas of the globe, in although they hold the key to many of our climate´s secrets. How does the sea ice coverage and the sea water properties change? How do plants and animals survive under the most extreme conditions of the earth? Which information of past climate change can be read from the sediments at the sea-floor and how can the future changing climate be predicted? In order to answer such and further questions, for the moment a hypermodern research vessel, the AURORA BOREALIS, is planned, which can handle the cool summers and freezing winters of the polar oceans and which can drill deep into the sea floor. AURORA BOREALIS will be the most advanced Research Icebreaker in the world with a multi-functional role of drilling in deep ocean basins and supporting climate/environmental research and decision support for stakeholder governments for the next 35-40 years. It will have a high icebreaking capacity to penetrate autonomously (single ship ...

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Research paper thumbnail of Modern distribution of dinocysts from the North Pacific Ocean (37–64°N, 144°E–148°W) in relation to hydrographic conditions, sea-ice and productivity

Marine Micropaleontology, 2012

ABSTRACT Palynological analyses were performed on 53 surface sediment samples from the North Paci... more ABSTRACT Palynological analyses were performed on 53 surface sediment samples from the North Pacific Ocean, including the Bering and Okhotsk Seas (37-64 degrees N, 144 degrees E-148 degrees W), in order to document the relationships between the dinocyst distribution and sea-surface conditions (temperatures, salinities, primary productivity and sea-ice cover). Samples are characterized by concentrations ranging from 18 to 143816 cysts/cm(3) and the occurrence of 32 species. A canonical correspondence analysis (CCA) was carried out to determine the relationship between environmental variables and the distribution of dinocyst taxa. The first and second axes represent, respectively, 47% and 17.8% of the canonical variance. Axis 1 is positively correlated with all parameters except to the sea-ice and primary productivity in August, which are on the negative side. Results indicate that the composition of dinocyst assemblages is mostly controlled by temperature and that all environmental variables are correlated together. The CCA distinguishes 3 groups of dinocysts: the heterotrophic taxa, the genera Impagidinium and Spiniferites as well as the cyst of Pentapharsodinium dalei and Operculodinium centrocarpum. Five assemblage zones can be distinguished: 1) the Okhotsk Sea zone, which is associated to temperate and eutrophic conditions, seasonal up-wellings and Amur River discharges. It is characterized by the dominance of O. centrocarpum, Brigantedinium spp. and Islandinium minutum; 2) the Western Subarctic Gyre zone with subpolar and mesotrophic conditions due to the Kamchatka Current and Alaska Stream inflows. Assemblages are dominated by Nematosphaeropsis labyrinthus, Pyxidinopsis reticulata and Brigantedinium spp.; 3) the Bering Sea zone, depicting a subpolar environment, influenced by seasonal upwellings and inputs from the Anadyr and Yukon Rivers. It is characterized by the dominance of I. minutum and Brigantedinium spp.; 4) the Alaska Gyre zone with temperate conditions and nutrient-enriched surface waters, which is dominated by N. labyrinthus and Brigantedinium spp. and 5) the Kuroshio Extension-North Pacific-Subarctic Current zone characterized by a subtropical and oligotrophic environment, which is dominated by O. centrocarpum, N. labyrinthus and warm taxa of the genus Impagidinium. Transfer functions were tested using the modem analog technique (MAT) on the North Pacific Ocean (=359 sites) and the entire Northern Hemisphere databases (=1419 sites). Results confirm that the updated Northern Hemisphere database is suitable for further paleoenvironmental reconstructions, and the best results are obtained for temperatures with an accuracy of +/-1.7 degrees C.

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Research paper thumbnail of Varying growth rates in bamboo corals: sclerochronology and radiocarbon dating of a mid-Holocene deep-water gorgonian skeleton (Keratoisis sp.: Octocorallia) from Chatham Rise (New Zealand)

Facies, 2008

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Research paper thumbnail of Laminated sediments in the Bering Sea reveal atmospheric teleconnections to Greenland climate on millennial to decadal timescales during the last deglaciation

Climate of the Past, 2014

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Research paper thumbnail of Sclerochronology of a mid-Holocene Bamboo Coral Skeleton: Incremental Growth and Radiocarbon Dating

... HR: 1340h AN: PP23D-1801 TI: Sclerochronology of a mid-Holocene Bamboo Coral Skeleton: Increm... more ... HR: 1340h AN: PP23D-1801 TI: Sclerochronology of a mid-Holocene Bamboo Coral Skeleton: Incremental Growth and Radiocarbon Dating AU: * Noe, SU EM: snoe@ifm ...

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Research paper thumbnail of Deep-Water Isidid Gorgonians As High-Resolution Archives of Paleoceanographic Dynamics In The Western Pacific (Chatham Rise, New Zealand And Sea Of Okhotsk)

Isidid gorgonians (octocorals) represent potential archives of past oceanic and climatic dynamics... more Isidid gorgonians (octocorals) represent potential archives of past oceanic and climatic dynamics in intermediate water masses, based on the chemical composition of their slow-growing skeletons. The growth mode of recovered fossil, subrecent and recent isidid skeletons is characterised by a simultaneous lateral secretion of concentric increments around an organo-mineralic central axis and vertical accretion of alternating organic nodes and internodes

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Research paper thumbnail of Glacial reduction and millennial-scale variations in Drake Passage throughflow

Proceedings of the National Academy of Sciences, 2015

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Research paper thumbnail of Variations of an oxygen minimum zone in the Okhotsk Sea over the last glacial-interglacial cycle as recorded by benthic foraminiferal and sedimentological data

At present, the Okhotsk Sea contributes to ventilation of intermediate NW-Pacific via production ... more At present, the Okhotsk Sea contributes to ventilation of intermediate NW-Pacific via production of the oxygenated Okhotsk Sea Intermediate Water (OSIW: ~200-800 m). In the Okhotsk Sea, oxygen minimum zone appears as water layer between ~800 and 1500 m water depths with oxygen contents 0.3-1.5 ml/l. The paleoreconstructions of the OSIW production and the OMZ intensity in the Okhotsk Sea are important to understand the glacial-interglacial variations of oxygenation / ventilation of intermediate NW-Pacific. This study presents high-resolution benthic foraminiferal and sedimentological data for the last 115 ka of the IMAGES core MD01-2415 (Figure 1). The resulting reconstructions of the OMZ intensity for core MD01-2415 are compared with those for the KOMEX cores: LV28-2-4, LV28-40-5 and LV28-43-5 covering the last 52, 80 and 46 ka, respectively. To reconstruct intensity of the OMZ, we applied downcore distributions of the relative abundance (%) and accumulation rate (AR, sp. cm/kyr) of...

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Research paper thumbnail of Future Marine Polar Research Capacities - Science Planning and Research Services for a Multi-National Research Icebreaker

Despite significant advances in Arctic and Antarctic marine science over the past years, the pola... more Despite significant advances in Arctic and Antarctic marine science over the past years, the polar Southern Ocean remains a formidable frontier due to challenging technical and operational requirements. Thus, key data and observations from this important region are still missing or lack adequate lateral and temporal coverage, especially from time slots outside optimal weather seasons and ice conditions. These barriers combined with the obligation to efficiently use financial resources and funding for expeditions call for new approaches to create optimally equipped, but cost-effective infrastructures. These must serve the international science community in a dedicated long-term mode and enable participation in multi-disciplinary expeditions, with secured access to optimally equipped marine platforms for world-class research in a wide range of Antarctic science topics. The high operational and technical performance capacity of a future joint European Research Icebreaker and Deep-sea D...

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Research paper thumbnail of Aurora Borealis—Development of a New Research Icebreaker with Drililng Capability

Scientific Drilling, 2007

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Research paper thumbnail of Transdisciplinarity and Training Engaged Researchers

Ocean Yearbook Online, 2014

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Research paper thumbnail of A mid-Holocene shift and millennial-scale variations in North Pacific mesopelagic oxygenation and upper mixed layer hydrography

ABSTRACT The subarctic North Pacific and its marginal seas constitute a key area in which rapid e... more ABSTRACT The subarctic North Pacific and its marginal seas constitute a key area in which rapid environmental changes over the past decades have been observed in instrumental records, like sea ice decreases, or alterations of nutrient inventories and oxygenation of mid-depth water masses. However, knowledge about the past climatic and oceanographic variability beyond instrumental time series in the subarctic North Pacific and its marginal seas is limited. Few temporally and spatially well-resolved high-resolution and spatially well datasets exist, with spatial and temporal coverage being insufficient to gain a detailed picture of past variations. Our proxydata-based study focuses on a collection of sediment records from the Okhotsk Sea as major source area for well ventilated North Pacific Intermediate Water (NPIW) that cover the last ca. 12,000 years with high temporal and adequate spatial resolution. We decipher rapid changes in NPIW ventilation patterns on centennial to millennial time scales and show that the current ventilation of the mid-depth North Pacific has likely only been prevalent for the last 2 ka. We further provide evidence for a Mid-Holocene shift in mid-depth NPIW ventilation characteristics. Additionally, changes in North Atlantic Deep Water flow speed and patterns are reflected in our records of North Pacific mid-depth water mass dynamics, thus indicating a hemispheric-wide connection between the Atlantic and Pacific regions during the Holocene. Planktic oxygen isotope data suggest a high variability in the stratification of local surface water masses and the formation of sea ice, influencing the formation of new, well ventilated water masses near to our core sites. We compare the main Holocene baseline changes evidenced in our proxy reconstructions to Early Holocene and Pre-Industrial time slice results from the fully-coupled MPI-ESM (COSMOS) Earth System Model, with a focus on the Pacific Ocean to better understand NPIW and upper ocean dynamic changes.

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Research paper thumbnail of Drilling Polar Oceans with the European Research Icebreaker AURORA BOREALIS: the IODP Context

Polar oceans are characterized by extreme environmental conditions for humans and materials, and ... more Polar oceans are characterized by extreme environmental conditions for humans and materials, and have remained the least accessible regions to scientists of the IODP. DSDP and ODP have for long faced specific technical and logistical problems when attempting to drill in ice-covered polar deep-sea basins. The Arctic Ocean and large areas of the high-latitude Southern Ocean remained largely un-sampled by

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Research paper thumbnail of Variations of the oxygen minimum zone of the Okhotsk Sea during the last 50 ka as indicated by benthic foraminiferal and biogeochemical data

Oceanology, 2010

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Research paper thumbnail of Sea surface temperature variability and sea-ice extent in the subarctic northwest Pacific during the past 15,000 years

Paleoceanography, 2012

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Research paper thumbnail of Deglacial development of (sub) sea surface temperature and salinity in the subarctic northwest Pacific: Implications for upper-ocean stratification

Paleoceanography, 2013

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Research paper thumbnail of Stationkeeping in Solid Drift Ice

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Research paper thumbnail of AURORA BOREALIS A new European Combined Research Icebreaker and Drilling Vessel

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Development of New Offshore and Icebreaker Technologies for the European Research Icebreaker Consortium's Research Infrastructure

Bookmarks Related papers MentionsView impact

Research paper thumbnail of The european research icebreaker AURORA BOREALIS : conceptual design study - summary report = Der europäische Forschungseisbrecher AURORA BOREALIS : Konzeptioneller Schiffsentwurf - Abschlussbericht

Bookmarks Related papers MentionsView impact

Research paper thumbnail of AURORA BOREALIS - European Research Icebreaker With Drilling Capability

The polar oceans are the least known areas of the globe, in although they hold the key to many of... more The polar oceans are the least known areas of the globe, in although they hold the key to many of our climate´s secrets. How does the sea ice coverage and the sea water properties change? How do plants and animals survive under the most extreme conditions of the earth? Which information of past climate change can be read from the sediments at the sea-floor and how can the future changing climate be predicted? In order to answer such and further questions, for the moment a hypermodern research vessel, the AURORA BOREALIS, is planned, which can handle the cool summers and freezing winters of the polar oceans and which can drill deep into the sea floor. AURORA BOREALIS will be the most advanced Research Icebreaker in the world with a multi-functional role of drilling in deep ocean basins and supporting climate/environmental research and decision support for stakeholder governments for the next 35-40 years. It will have a high icebreaking capacity to penetrate autonomously (single ship ...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Modern distribution of dinocysts from the North Pacific Ocean (37–64°N, 144°E–148°W) in relation to hydrographic conditions, sea-ice and productivity

Marine Micropaleontology, 2012

ABSTRACT Palynological analyses were performed on 53 surface sediment samples from the North Paci... more ABSTRACT Palynological analyses were performed on 53 surface sediment samples from the North Pacific Ocean, including the Bering and Okhotsk Seas (37-64 degrees N, 144 degrees E-148 degrees W), in order to document the relationships between the dinocyst distribution and sea-surface conditions (temperatures, salinities, primary productivity and sea-ice cover). Samples are characterized by concentrations ranging from 18 to 143816 cysts/cm(3) and the occurrence of 32 species. A canonical correspondence analysis (CCA) was carried out to determine the relationship between environmental variables and the distribution of dinocyst taxa. The first and second axes represent, respectively, 47% and 17.8% of the canonical variance. Axis 1 is positively correlated with all parameters except to the sea-ice and primary productivity in August, which are on the negative side. Results indicate that the composition of dinocyst assemblages is mostly controlled by temperature and that all environmental variables are correlated together. The CCA distinguishes 3 groups of dinocysts: the heterotrophic taxa, the genera Impagidinium and Spiniferites as well as the cyst of Pentapharsodinium dalei and Operculodinium centrocarpum. Five assemblage zones can be distinguished: 1) the Okhotsk Sea zone, which is associated to temperate and eutrophic conditions, seasonal up-wellings and Amur River discharges. It is characterized by the dominance of O. centrocarpum, Brigantedinium spp. and Islandinium minutum; 2) the Western Subarctic Gyre zone with subpolar and mesotrophic conditions due to the Kamchatka Current and Alaska Stream inflows. Assemblages are dominated by Nematosphaeropsis labyrinthus, Pyxidinopsis reticulata and Brigantedinium spp.; 3) the Bering Sea zone, depicting a subpolar environment, influenced by seasonal upwellings and inputs from the Anadyr and Yukon Rivers. It is characterized by the dominance of I. minutum and Brigantedinium spp.; 4) the Alaska Gyre zone with temperate conditions and nutrient-enriched surface waters, which is dominated by N. labyrinthus and Brigantedinium spp. and 5) the Kuroshio Extension-North Pacific-Subarctic Current zone characterized by a subtropical and oligotrophic environment, which is dominated by O. centrocarpum, N. labyrinthus and warm taxa of the genus Impagidinium. Transfer functions were tested using the modem analog technique (MAT) on the North Pacific Ocean (=359 sites) and the entire Northern Hemisphere databases (=1419 sites). Results confirm that the updated Northern Hemisphere database is suitable for further paleoenvironmental reconstructions, and the best results are obtained for temperatures with an accuracy of +/-1.7 degrees C.

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Research paper thumbnail of Varying growth rates in bamboo corals: sclerochronology and radiocarbon dating of a mid-Holocene deep-water gorgonian skeleton (Keratoisis sp.: Octocorallia) from Chatham Rise (New Zealand)

Facies, 2008

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Research paper thumbnail of Laminated sediments in the Bering Sea reveal atmospheric teleconnections to Greenland climate on millennial to decadal timescales during the last deglaciation

Climate of the Past, 2014

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Sclerochronology of a mid-Holocene Bamboo Coral Skeleton: Incremental Growth and Radiocarbon Dating

... HR: 1340h AN: PP23D-1801 TI: Sclerochronology of a mid-Holocene Bamboo Coral Skeleton: Increm... more ... HR: 1340h AN: PP23D-1801 TI: Sclerochronology of a mid-Holocene Bamboo Coral Skeleton: Incremental Growth and Radiocarbon Dating AU: * Noe, SU EM: snoe@ifm ...

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Research paper thumbnail of Deep-Water Isidid Gorgonians As High-Resolution Archives of Paleoceanographic Dynamics In The Western Pacific (Chatham Rise, New Zealand And Sea Of Okhotsk)

Isidid gorgonians (octocorals) represent potential archives of past oceanic and climatic dynamics... more Isidid gorgonians (octocorals) represent potential archives of past oceanic and climatic dynamics in intermediate water masses, based on the chemical composition of their slow-growing skeletons. The growth mode of recovered fossil, subrecent and recent isidid skeletons is characterised by a simultaneous lateral secretion of concentric increments around an organo-mineralic central axis and vertical accretion of alternating organic nodes and internodes

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Glacial reduction and millennial-scale variations in Drake Passage throughflow

Proceedings of the National Academy of Sciences, 2015

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Variations of an oxygen minimum zone in the Okhotsk Sea over the last glacial-interglacial cycle as recorded by benthic foraminiferal and sedimentological data

At present, the Okhotsk Sea contributes to ventilation of intermediate NW-Pacific via production ... more At present, the Okhotsk Sea contributes to ventilation of intermediate NW-Pacific via production of the oxygenated Okhotsk Sea Intermediate Water (OSIW: ~200-800 m). In the Okhotsk Sea, oxygen minimum zone appears as water layer between ~800 and 1500 m water depths with oxygen contents 0.3-1.5 ml/l. The paleoreconstructions of the OSIW production and the OMZ intensity in the Okhotsk Sea are important to understand the glacial-interglacial variations of oxygenation / ventilation of intermediate NW-Pacific. This study presents high-resolution benthic foraminiferal and sedimentological data for the last 115 ka of the IMAGES core MD01-2415 (Figure 1). The resulting reconstructions of the OMZ intensity for core MD01-2415 are compared with those for the KOMEX cores: LV28-2-4, LV28-40-5 and LV28-43-5 covering the last 52, 80 and 46 ka, respectively. To reconstruct intensity of the OMZ, we applied downcore distributions of the relative abundance (%) and accumulation rate (AR, sp. cm/kyr) of...

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Future Marine Polar Research Capacities - Science Planning and Research Services for a Multi-National Research Icebreaker

Despite significant advances in Arctic and Antarctic marine science over the past years, the pola... more Despite significant advances in Arctic and Antarctic marine science over the past years, the polar Southern Ocean remains a formidable frontier due to challenging technical and operational requirements. Thus, key data and observations from this important region are still missing or lack adequate lateral and temporal coverage, especially from time slots outside optimal weather seasons and ice conditions. These barriers combined with the obligation to efficiently use financial resources and funding for expeditions call for new approaches to create optimally equipped, but cost-effective infrastructures. These must serve the international science community in a dedicated long-term mode and enable participation in multi-disciplinary expeditions, with secured access to optimally equipped marine platforms for world-class research in a wide range of Antarctic science topics. The high operational and technical performance capacity of a future joint European Research Icebreaker and Deep-sea D...

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Research paper thumbnail of Aurora Borealis—Development of a New Research Icebreaker with Drililng Capability

Scientific Drilling, 2007

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Transdisciplinarity and Training Engaged Researchers

Ocean Yearbook Online, 2014

Bookmarks Related papers MentionsView impact

Research paper thumbnail of A mid-Holocene shift and millennial-scale variations in North Pacific mesopelagic oxygenation and upper mixed layer hydrography

ABSTRACT The subarctic North Pacific and its marginal seas constitute a key area in which rapid e... more ABSTRACT The subarctic North Pacific and its marginal seas constitute a key area in which rapid environmental changes over the past decades have been observed in instrumental records, like sea ice decreases, or alterations of nutrient inventories and oxygenation of mid-depth water masses. However, knowledge about the past climatic and oceanographic variability beyond instrumental time series in the subarctic North Pacific and its marginal seas is limited. Few temporally and spatially well-resolved high-resolution and spatially well datasets exist, with spatial and temporal coverage being insufficient to gain a detailed picture of past variations. Our proxydata-based study focuses on a collection of sediment records from the Okhotsk Sea as major source area for well ventilated North Pacific Intermediate Water (NPIW) that cover the last ca. 12,000 years with high temporal and adequate spatial resolution. We decipher rapid changes in NPIW ventilation patterns on centennial to millennial time scales and show that the current ventilation of the mid-depth North Pacific has likely only been prevalent for the last 2 ka. We further provide evidence for a Mid-Holocene shift in mid-depth NPIW ventilation characteristics. Additionally, changes in North Atlantic Deep Water flow speed and patterns are reflected in our records of North Pacific mid-depth water mass dynamics, thus indicating a hemispheric-wide connection between the Atlantic and Pacific regions during the Holocene. Planktic oxygen isotope data suggest a high variability in the stratification of local surface water masses and the formation of sea ice, influencing the formation of new, well ventilated water masses near to our core sites. We compare the main Holocene baseline changes evidenced in our proxy reconstructions to Early Holocene and Pre-Industrial time slice results from the fully-coupled MPI-ESM (COSMOS) Earth System Model, with a focus on the Pacific Ocean to better understand NPIW and upper ocean dynamic changes.

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Drilling Polar Oceans with the European Research Icebreaker AURORA BOREALIS: the IODP Context

Polar oceans are characterized by extreme environmental conditions for humans and materials, and ... more Polar oceans are characterized by extreme environmental conditions for humans and materials, and have remained the least accessible regions to scientists of the IODP. DSDP and ODP have for long faced specific technical and logistical problems when attempting to drill in ice-covered polar deep-sea basins. The Arctic Ocean and large areas of the high-latitude Southern Ocean remained largely un-sampled by

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Variations of the oxygen minimum zone of the Okhotsk Sea during the last 50 ka as indicated by benthic foraminiferal and biogeochemical data

Oceanology, 2010

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Sea surface temperature variability and sea-ice extent in the subarctic northwest Pacific during the past 15,000 years

Paleoceanography, 2012

Bookmarks Related papers MentionsView impact

Research paper thumbnail of Deglacial development of (sub) sea surface temperature and salinity in the subarctic northwest Pacific: Implications for upper-ocean stratification

Paleoceanography, 2013

Bookmarks Related papers MentionsView impact