scholarly journals Archaeal distribution and abundance in water masses of the Arctic Ocean, Pacific sector

2013 ◽  
Vol 69 (2) ◽  
pp. 101-112 ◽  
Author(s):  
C Amano-Sato ◽  
S Akiyama ◽  
M Uchida ◽  
K Shimada ◽  
M Utsumi
Keyword(s):  
Arctic Ocean ◽  
Water Masses ◽  
The Arctic ◽  
The Arctic Ocean

Spatial Distributions of DDTs in the Water Masses of the Arctic Ocean

2017 ◽  
Vol 51 (14) ◽  
pp. 7913-7919 ◽  
Author(s):  
Daniel Carrizo ◽  
Anna Sobek ◽  
Joan A. Salvadó ◽  
Örjan Gustafsson
Keyword(s):  
Arctic Ocean ◽  
Water Masses ◽  
The Arctic ◽  
Spatial Distributions ◽  
The Arctic Ocean

scholarly journals Upper Arctic Ocean water masses harbor distinct communities of heterotrophic flagellates

2013 ◽  
Vol 10 (6) ◽  
pp. 4273-4286 ◽  
Author(s):  
A. Monier ◽  
R. Terrado ◽  
M. Thaler ◽  
A. Comeau ◽  
E. Medrinal ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Water Column ◽  
Community Composition ◽  
Beaufort Sea ◽  
Water Masses ◽  
The Arctic ◽  
Heterotrophic Flagellates ◽  
Chlorophyll Maximum ◽  
Subsurface Chlorophyll Maximum ◽  
The Arctic Ocean

Abstract. The ubiquity of heterotrophic flagellates (HFL) in marine waters has been recognized for several decades, but the phylogenetic diversity of these small (ca. 0.8–20 μm cell diameter), mostly phagotrophic protists in the upper pelagic zone of the ocean is underappreciated. Community composition of microbes, including HFL, is the result of past and current environmental selection, and different taxa may be indicative of food webs that cycle carbon and energy very differently. While all oceanic water columns can be density stratified due to the temperature and salinity characteristics of different water masses, the Arctic Ocean is particularly well stratified, with nutrients often limiting in surface waters and most photosynthetic biomass confined to a subsurface chlorophyll maximum layer, where light and nutrients are both available. This physically well-characterized system provided an opportunity to explore the community diversity of HFL from different water masses within the water column. We used high-throughput DNA sequencing techniques as a rapid means of surveying the diversity of HFL communities in the southern Beaufort Sea (Canada), targeting the surface, the subsurface chlorophyll maximum layer (SCM) and just below the SCM. In addition to identifying major clades and their distribution, we explored the micro-diversity within the globally significant but uncultivated clade of marine stramenopiles (MAST-1) to examine the possibility of niche differentiation within the stratified water column. Our results strongly suggested that HFL community composition was determined by water mass rather than geographical location across the Beaufort Sea. Future work should focus on the biogeochemical and ecological repercussions of different HFL communities in the face of climate-driven changes to the physical structure of the Arctic Ocean.

scholarly journals Multibeam Bathymetry and CTD-Measurements in two fjord systems in Southeast Greenland

2017 ◽  
Author(s):  
Kristian Kjellerup Kjeldsen ◽  
Wilhelm Weinrebe ◽  
Jørgen Bendtsen ◽  
Anders Anker Bjørk ◽  
Kurt Henrik Kjær
Keyword(s):  
Arctic Ocean ◽  
Bottom Water ◽  
Outer Part ◽  
Satellite Observations ◽  
Water Masses ◽  
The Arctic ◽  
Multibeam Bathymetry ◽  
The Arctic Ocean ◽  
Bathymetric Map ◽  
Subglacial Meltwater

Abstract. We present bathymetry and hydrological observations collected in the summer of 2014 from two fjord systems in Southeast Greenland, using SS Activ with a multibeam system temporally installed over the side of the ship. Our results provide a detailed bathymetric map of the fjord complex around Skjoldungen Island and the outer part of Timmiarmiut Fjord and show far greater depths compared to the International Bathymetric Chart of the Arctic Ocean. The hydrography collected show different properties in the fjords with the bottom water masses below 240 m in Timmiarmiut Fjord being 1–2 °C warmer than in the two fjords around Skjoldungen Island, but data also illustrate the influence of sills on the exchange of deeper water masses within fjords. Moreover, evidence of subglacial discharge in Timmiarmiut Fjord, consistent with satellite observations of ice mélange set into motion, adds to our increasing understanding of the distribution of subglacial meltwater. Data is available through the PANGAEA website https://doi.pangaea.de/10.1594/PANGAEA.860627.

Transports of Nordic Seas water masses and excess SF6 through Fram Strait to the Arctic Ocean

2008 ◽  
Vol 78 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Marika Marnela ◽  
Bert Rudels ◽  
K. Anders Olsson ◽  
Leif G. Anderson ◽  
Emil Jeansson ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Water Masses ◽  
The Arctic ◽  
Fram Strait ◽  
Nordic Seas ◽  
The Arctic Ocean

scholarly journals Upper Arctic Ocean water masses harbor distinct communities of heterotrophic flagellates

2013 ◽  
Vol 10 (2) ◽  
pp. 3397-3430 ◽  
Author(s):  
A. Monier ◽  
R. Terrado ◽  
M. Thaler ◽  
A. M. Comeau ◽  
E. Medrinal ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Water Column ◽  
Community Composition ◽  
Beaufort Sea ◽  
Water Masses ◽  
Community Diversity ◽  
The Arctic ◽  
Heterotrophic Flagellates ◽  
Environmental Selection ◽  
The Arctic Ocean

Abstract. The ubiquity of heterotrophic flagellates (HFL) in marine waters has been recognized for several decades, but the phylogenetic diversity of these small (ca. 0.8–20 μm cell diameter), mostly phagotrophic protists in the pelagic zone of the ocean is underappreciated. Community composition of microbes, including HFL, is the result of past and current environmental selection, and different taxa may be indicative of food webs that cycle carbon and energy very differently. While all oceanic water columns can be density stratified due to the temperature and salinity characteristics of different water masses, the Arctic Ocean is particularly well stratified, with nutrients often limiting in surface waters and most photosynthetic biomass confined to a subsurface chlorophyll maximum (SCM) layer. This physically well-characterized system provided an opportunity to explore the community diversity of HFL across a wide region, and down the water column. We used high-throughput DNA sequencing techniques as a rapid means of surveying the diversity of HFL communities in the southern Beaufort Sea (Canada), targeting the surface, the SCM and just below the SCM. In addition to identifying major clades and their distribution, we explored the micro-diversity within the globally significant but uncultivated clade of marine stramenopiles (MAST-1) to examine the possibility of niche differentiation within the stratified water column. Our results strongly implied that HFL community composition was determined by water mass rather than geographical location across the Beaufort Sea. Future work should focus on the biogeochemical and ecological repercussions of different HFL communities in the face of climate driven changes to the physical structure of the Arctic Ocean.

The modern Northeast Atlantic Radiocarbon Content viewed along a basin transect from 29°- 61°N

2020 ◽  
Author(s):  
Norbert Frank ◽  
Markus Miltner ◽  
Steffen Therre ◽  
Marleen Lausecker ◽  
Nadine Tisnerat-Laborde ◽  
...  
Keyword(s):  
Arctic Ocean ◽  
Dissolved Inorganic Carbon ◽  
Water Masses ◽  
The Arctic ◽  
Carbon Uptake ◽  
East Atlantic ◽  
Northeast Atlantic ◽  
The North ◽  
Basin Scale ◽  
The Arctic Ocean

<p>The Northeast Atlantic is crucial regarding the northward heat and carbon export into the Arctic Ocean. At the surface and at mid-depth (0 -1000 m), however, most of the water re-circulates through two basin scale gyres, with warm and salty waters in the sub-tropical gyre (STG) and significantly fresher and colder waters in the sub-polar gyre (SPG). In addition, the Azores Front (AF) separates the northeastern branch from the southeastern branch of the STG, which is today positioned around 34.5°N in the east Atlantic. Underneath both gyres newly formed deep waters from the Arctic Ocean and Labrador Sea are spread into the Atlantic basin. Here we investigate, whether these water masses and recirculation patterns reveal distinct histories of carbon uptake and advection in the eastern North Atlantic. Therefore, water samples spanning the entire water column have been collected at 6 stations along a north-south transect at 25°W spanning from 42° to 61°N in 2012 (N/O Thalassa ICE-CTD cruise). In 2018 (RV Meteor M151 ATHENA cruise) samples further south were collected spanning until 29.5°N thus including the present day AF.</p><p>The radiocarbon content of Dissolved Inorganic Carbon (DIC) from 8 profiles (N>60, 30° to 61°N, 50-3000m depth) were measured at the AMS facility at CEZA facility in Mannheim following CO<sub>2</sub> extraction from seawater at Heidelberg University. Δ<sup>14</sup>C values range from +50 ‰ in the upper layers of the subtropical Atlantic to -100 ‰ in 3000 m depth also in the subtropical Atlantic. Three main feature appear in the radiocarbon distribution. The surface shows a moderate difference between SPG and STG Δ<sup>14</sup>C values of <15‰ with a decreasing trend towards the North, hence indicating equilibration with the atmosphere. Underneath, between 100-1000 m depth SPG (46° – 61°N) Δ<sup>14</sup>C values of nearly 0‰ are found identical to the modern Northern Hemisphere atmosphere. In contrast, the STG (30°-43°N) reveals up to 50‰ enriched water reflecting limited carbon uptake from the atmosphere. Thus this layer will act as a source of radiocarbon to the polar seas and atmosphere in the near future. Below, between 1000 and 2000 m water masses north of the AF reveal a nearly homogeneous Δ<sup>14</sup>C value of -10‰ with a moderate decreasing trend with depth. South of the AF Δ<sup>14</sup>C values show a strong decrease with depth from 0 to -75‰, hence water masses remain still little affected by the advection of bomb radiocarbon (thus anthropogenic carbon). Thus, as expected the AF and the mid-depth gyre play a crucial role in distributing carbon throughout the east Atlantic.</p>

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