scholarly journals Impact of increasing inflow of warm Atlantic water on the sea‐air exchange of carbon dioxide and methane in the Laptev Sea

2016 ◽  
Vol 121 (7) ◽  
pp. 1867-1883
Author(s):  
Iréne Wåhlström ◽  
Christian Dieterich ◽  
Per Pemberton ◽  
H. E. Markus Meier
Keyword(s):  
Carbon Dioxide ◽  
Atlantic Water ◽  
Laptev Sea ◽  
The Laptev Sea ◽  
Air Exchange

scholarly journals Mooring-Based Observations of Double-Diffusive Staircases over the Laptev Sea Slope*

2012 ◽  
Vol 42 (1) ◽  
pp. 95-109 ◽  
Author(s):  
Igor V. Polyakov ◽  
Andrey V. Pnyushkov ◽  
Robert Rember ◽  
Vladimir V. Ivanov ◽  
Y.-D. Lenn ◽  
...  
Keyword(s):  
Double Diffusion ◽  
Atlantic Water ◽  
Arctic Sea Ice ◽  
Heat Fluxes ◽  
Laptev Sea ◽  
Depth Range ◽  
Diffusive Convection ◽  
Arctic Sea ◽  
Effective Transfer ◽  
The Laptev Sea

Abstract A yearlong time series from mooring-based high-resolution profiles of water temperature and salinity from the Laptev Sea slope (2003–04; 2686-m depth; 78°26′N, 125°37′E) shows six remarkably persistent staircase layers in the depth range of ~140–350 m encompassing the upper Atlantic Water (AW) and lower halocline. Despite frequent displacement of isopycnal surfaces by internal waves and eddies and two strong AW warming pulses that passed through the mooring location in February and late August 2004, the layers preserved their properties. Using laboratory-derived flux laws for diffusive convection, the authors estimate the time-averaged diapycnal heat fluxes across the four shallower layers overlying the AW core to be ~8 W m−2. Temporal variability of these fluxes is strong, with standard deviations of ~3–7 W m−2. These fluxes provide a means for effective transfer of AW heat upward over more than a 100-m depth range toward the upper halocline. These findings suggest that double diffusion is an important mechanism influencing the oceanic heat fluxes that help determine the state of Arctic sea ice.

scholarly journals Modified Halocline Water over the Laptev Sea Continental Margin: Historical Data Analysis

2012 ◽  
Vol 25 (16) ◽  
pp. 5556-5565 ◽  
Author(s):  
Igor A. Dmitrenko ◽  
Sergey A. Kirillov ◽  
Vladimir V. Ivanov ◽  
Bert Rudels ◽  
Nuno Serra ◽  
...  
Keyword(s):  
Continental Margin ◽  
North Atlantic Ocean ◽  
Source Region ◽  
Vertical Mixing ◽  
Atlantic Water ◽  
Laptev Sea ◽  
Boundary Current ◽  
Salinity Stratification ◽  
The North ◽  
The Laptev Sea

Abstract Historical hydrographic data (1940s–2010) show a distinct cross-slope difference of the lower halocline water (LHW) over the Laptev Sea continental margins. Over the slope, the LHW is on average warmer and saltier by 0.2°C and 0.5 psu, respectively, relative to the off-slope LHW. The LHW temperature time series constructed from the on-slope historical records are related to the temperature of the Atlantic Water (AW) boundary current transporting warm water from the North Atlantic Ocean. In contrast, the on-slope LHW salinity is linked to the sea ice and wind forcing over the potential upstream source region in the Barents and northern Kara Seas, as also indicated by hydrodynamic model results. Over the Laptev Sea continental margin, saltier LHW favors weaker salinity stratification that, in turn, contributes to enhanced vertical mixing with underlying AW.

scholarly journals Changes in the paleohydrological conditions in the Laptev Sea during the late Pleistocene and Holocene based on a study of aquatic palynomorphs

2019 ◽  
Vol 59 (3) ◽  
pp. 433-448
Author(s):  
T. S. Klyuvitkina ◽  
Ye. I. Polyakova
Keyword(s):  
Environmental Change ◽  
Sea Level ◽  
Continental Margin ◽  
Cold Water ◽  
Sediment Cores ◽  
Atlantic Water ◽  
Time Interval ◽  
Laptev Sea ◽  
Global Sea Level ◽  
The Laptev Sea

On the basis of aquatic palynomorph assemblages in sediment cores obtained from the eastern Laptev Sea shelf, major phases of environmental change associated with the last postglacial global sea-level rise can be recognized for the time since 17.5 calendar years BP (cal. ka). It is shown that in the time interval of 17.5–13.0 cal. ka in the western part of the sea there was a very cold-water sea basin with permanent sea-ice cover, 12.3–11.2 cal. ka the outer shelf were characterized by increased precipitation of river-loaded matter in a river-proximal environment of Anabara and Khatanga rivers, and the period of 11.2–7.0 cal ka was marked by enhanced influence of Atlantic water at the Laptev Sea continental margin. Modern-like environments were established in this part of the sea approximately 7.0 cal. ka.

Seasonal variability of Atlantic water on the continental slope of the Laptev Sea during 2002–2004

2006 ◽  
Vol 244 (3-4) ◽  
pp. 735-743 ◽  
Author(s):  
Igor A. Dmitrenko ◽  
Igor V. Polyakov ◽  
Sergey A. Kirillov ◽  
Leonid A. Timokhov ◽  
Harper L. Simmons ◽  
...  
Keyword(s):  
Continental Slope ◽  
Seasonal Variability ◽  
Atlantic Water ◽  
Laptev Sea ◽  
The Laptev Sea

scholarly journals Composition of Sedimentary Organic Matter across the Laptev Sea Shelf: Evidences from Rock-Eval Parameters and Molecular Indicators

Water ◽  
2020 ◽  
Vol 12 (12) ◽  
pp. 3511
Author(s):  
Elena Gershelis ◽  
Andrey Grinko ◽  
Irina Oberemok ◽  
Elizaveta Klevantseva ◽  
Natalina Poltavskaya ◽  
...  
Keyword(s):  
Organic Matter ◽  
Surface Sediments ◽  
Continental Margins ◽  
Laptev Sea ◽  
Lena River ◽  
Nearshore Sediments ◽  
Rock Eval ◽  
Molecular Indicators ◽  
Sedimentation Regime ◽  
The Laptev Sea

Global warming in high latitudes causes destabilization of vulnerable permafrost deposits followed by massive thaw-release of organic carbon. Permafrost-derived carbon may be buried in the nearshore sediments, transported towards the deeper basins or degraded into the greenhouse gases, potentially initiating a positive feedback to climate change. In the present study, we aim to identify the sources, distribution and degradation state of organic matter (OM) stored in the surface sediments of the Laptev Sea (LS), which receives a large input of terrestrial carbon from both Lena River discharge and intense coastal erosion. We applied a suite of geochemical indicators including the Rock Eval parameters, traditionally used for the matured OM characterization, and terrestrial lipid biomarkers. In addition, we analyzed a comprehensive grain size data in order to assess hydrodynamic sedimentation regime across the LS shelf. Rock-Eval (RE) data characterize LS sedimentary OM with generally low hydrogen index (100–200 mg HC/g TOC) and oxygen index (200 and 300 CO2/g TOC) both increasing off to the continental slope. According to Tpeak values, there is a clear regional distinction between two groups (369–401 °C for the inner and mid shelf; 451–464 °C for the outer shelf). We suggest that permafrost-derived OM is traced across the shallow and mid depths with high Tpeak and slightly elevated HI values if compared to other Arctic continental margins. Molecular-based degradation indicators show a trend to more degraded terrestrial OC with increasing distance from the coast corroborating with RE results. However, we observed much less variation of the degradation markers down to the deeper sampling horizons, which supports the notion that the most active OM degradation in LS land-shelf system takes part during the cross-shelf transport, not while getting buried deeper.

scholarly journals Emission of harmful gases from animal production in Poland

2021 ◽  
Vol 193 (6) ◽  
Author(s):  
Kamila Mazur ◽  
Kamil Roman ◽  
Witold Jan Wardal ◽  
Kinga Borek ◽  
Jan Barwicki ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Ammonia Concentration ◽  
Herd Size ◽  
Animal Production ◽  
Ammonia Emission ◽  
Emission Rates ◽  
Housing Systems ◽  
Air Exchange Rate ◽  
Microclimate Conditions ◽  
Air Exchange

AbstractThe aim of the study was to present the scale of greenhouse gas emissions from animal production, and to provide test results from different housing systems. In three free stall buildings, two with slurry in deep channels and one with cattle in cubicles staying on shallow litter concentration of ammonia and carbon dioxide were measured in summer season by using dedicated equipment from Industrial Scientific Research. Air exchange was calculated on the base of balance carbon dioxide method. This method was used in order to estimate the air flow rate. Concentrations of ammonia and CO2 were measured as the base for air exchange and ammonia emission rates. Ammonia emissions were product of ammonia concentration and air exchange rate. Temperature and relative humidity were measured to establish microclimate conditions in buildings tested to show the overall microclimatic situation in buildings. Differences between ammonia emission rates were observed in both housing systems. The highest ammonia emission rate was equal to 2.75 g·h−1·LU−1 in well-ventilated cattle barn with the largest herd size.

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