scholarly journals Where can we find a seasonal cycle of the Atlantic water temperature within the Arctic Basin?

2012 ◽  
Vol 117 (C3) ◽  
pp. n/a-n/a ◽  
Author(s):  
Camille Lique ◽  
Michael Steele
Keyword(s):  
Water Temperature ◽  
Seasonal Cycle ◽  
Arctic Basin ◽  
Atlantic Water ◽  
The Arctic

scholarly journals Genesis and Decay of Mesoscale Baroclinic Eddies in the Seasonally Ice-Covered Interior Arctic Ocean

2021 ◽  
Vol 51 (1) ◽  
pp. 115-129
Author(s):  
Gianluca Meneghello ◽  
John Marshall ◽  
Camille Lique ◽  
Pål Erik Isachsen ◽  
Edward Doddridge ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Seasonal Cycle ◽  
Climate Models ◽  
Baroclinic Instability ◽  
Temporal Distribution ◽  
Arctic Basin ◽  
Ocean Model ◽  
The Arctic ◽  
Origin And Evolution

AbstractObservations of ocean currents in the Arctic interior show a curious, and hitherto unexplained, vertical and temporal distribution of mesoscale activity. A marked seasonal cycle is found close to the surface: strong eddy activity during summer, observed from both satellites and moorings, is followed by very quiet winters. In contrast, subsurface eddies persist all year long within the deeper halocline and below. Informed by baroclinic instability analysis, we explore the origin and evolution of mesoscale eddies in the seasonally ice-covered interior Arctic Ocean. We find that the surface seasonal cycle is controlled by friction with sea ice, dissipating existing eddies and preventing the growth of new ones. In contrast, subsurface eddies, enabled by interior potential vorticity gradients and shielded by a strong stratification at a depth of approximately 50 m, can grow independently of the presence of sea ice. A high-resolution pan-Arctic ocean model confirms that the interior Arctic basin is baroclinically unstable all year long at depth. We address possible implications for the transport of water masses between the margins and the interior of the Arctic basin, and for climate models’ ability to capture the fundamental difference in mesoscale activity between ice-covered and ice-free regions.

scholarly journals The Movement of Atlantic Water in the Arctic Ocean

ARCTIC ◽  
1963 ◽  
Vol 16 (1) ◽  
pp. 8 ◽  
Author(s):  
L.K. Coachman ◽  
C.A. Barnes
Keyword(s):  
Arctic Ocean ◽  
Arctic Basin ◽  
Core Layer ◽  
Atlantic Water ◽  
The Arctic ◽  
The Core ◽  
The Arctic Ocean ◽  
Percentage Retention ◽  
Oceanographic Data ◽  
Vertical Eddy

Re-evaluates sixty years' oceanographic data from the Arctic Ocean, examining nearly 300 deep-water stations, and using the "core-layer" method of Wust to interpret the movement of the Atlantic layer. Stations are grouped in 16 areas and the average curve for each group plotted on a temperature-salinity diagram. Temperature and salinity changes which take place in the Atlantic water while and entity in the Arctic Basin are graphed. The temperature maximum is reduced by about 3.5 C, and the salinity at max. temperature is reduced by about 0.2 %. Superimposed on the T-S relationship is an arbitrary scale indicating percentage retention of the original characteristics. The velocity of the Atlantic layer is found (from current velocity, eddy coefficients and station data) to range 1-10 cm/sec and values of Kz (vertical eddy coefficient) generally to range 1-20 sq cm/sec. Percentage retention of characteristics from the T-S diagram is mapped to suggest a relation between the flow of Atlantic water and bathymetry, distance, time, as well as the T-S features. Assuming the velocity along the core to be 3 cm/sec, the constant vertical eddy coefficient to be 10 sq cm/sec, and with other assumptions on temperature distribution, an estimate of 8,000,000 sq cm/sec is obtained for the constant lateral eddy coefficient.

scholarly journals Influence of Atlantic inflow on the freshwater content in the upper layer of the Arctic basin

2019 ◽  
Vol 65 (4) ◽  
pp. 363-388
Author(s):  
G. V. Alekseev ◽  
A. V. Pnyushkov ◽  
A. V. Smirnov ◽  
A. E. Vyazilova ◽  
N. I. Glok
Keyword(s):  
Fresh Water ◽  
Large Scale ◽  
Barents Sea ◽  
Lower Boundary ◽  
Arctic Basin ◽  
Water Layer ◽  
Atlantic Water ◽  
Water Masses ◽  
The Arctic ◽  
The North

Inter-decadal changes in the water layer of Atlantic origin and freshwater content (FWC) in the upper 100 m layer were traced jointly to assess the influence of inflows from the Atlantic on FWC changes based on oceanographic observations in the Arctic Basin for the 1960s – 2010s. For this assessment, we used oceanographic data collected at the Arctic and Antarctic Research Institute (AARI) and the International Arctic Research Center (IARC). The AARI data for the decades of 1960s – 1990s were obtained mainly at the North Pole drifting ice camps, in high-latitude aerial surveys in the 1970s, as well as in ship-based expeditions in the 1990s. The IARC database contains oceanographic measurements acquired using modern CTD (Conductivity – Temperature – Depth) systems starting from the 2000s. For the reconstruction of decadal fields of the depths of the upper and lower 0 °С isotherms and FWC in the 0–100 m layer in the periods with a relatively small number of observations (1970s – 1990s), we used a climatic regression method based on the conservativeness of the large-scale structure of water masses in the Arctic Basin. Decadal fields with higher data coverage were built using the DIVAnd algorithm. Both methods showed almost identical results when compared.  The results demonstrated that the upper boundary of the Atlantic water (AW) layer, identified with the depth of zero isotherm, raised everywhere by several tens of meters in 1990s – 2010s, when compared to its position before the start of warming in the 1970s. The lower boundary of the AW layer, also determined by the depth of zero isotherm, became deeper. Such displacements of the layer boundaries indicate an increase in the volume of water in the Arctic Basin coming not only through the Fram Strait, but also through the Barents Sea. As a result, the balance of water masses was disturbed and its restoration had to occur due to the reduction of the volume of the upper most dynamic freshened layer. Accordingly, the content of fresh water in this layer should decrease. Our results confirmed that FWC in the 0–100 m layer has decreased to 2 m in the Eurasian part of the Arctic Basin to the west of 180° E in the 1990s. In contrast, the FWC to the east of 180° E and closer to the shores of Alaska and the Canadian archipelago has increased. These opposite tendencies have been intensified in the 2000s and the 2010s. A spatial correlation between distributions of the FWC and the positions of the upper AW boundary over different decades confirms a close relationship between both distributions. The influence of fresh water inflow is manifested as an increase in water storage in the Canadian Basin and the Beaufort Gyre in the 1990s – 2010s. The response of water temperature changes from the tropical Atlantic to the Arctic Basin was traced, suggesting not only the influence of SST at low latitudes on changes in FWC, but indicating the distant tropical impact on Arctic processes. 

Temporal and spatial variability in Atlantic Water in the Arctic from observations

2021 ◽  
Author(s):  
Alice Richards ◽  
Helen Johnson ◽  
Camille Lique
Keyword(s):  
Spatial Variability ◽  
Arctic Basin ◽  
Water Layer ◽  
Atlantic Water ◽  
The Arctic ◽  
Potential Influence ◽  
Climatological Data ◽  
Arctic Regions ◽  
Temporal And Spatial Variability ◽  
Temporal And Spatial

<p>Observational data from across the Arctic are used to investigate temporal and spatial variability in Atlantic Water throughout the Arctic basin from the 1980s to the present day, with a focus on Atlantic Water heat and its potential influence on the upper water column. MIMOC climatological data are also used in the analysis. The inferred mechanisms behind Atlantic Water spread in the Arctic – both vertically and laterally into sub-basin interiors – are discussed, along with the local and remote influences on the Atlantic Water layer in different Arctic regions. The usefulness of the Atlantic Water core in tracking changes in the Atlantic Water layer is also assessed. </p>

Variability of the Intermediate Atlantic Water of the Arctic Ocean over the Last 100 Years

2004 ◽  
Vol 17 (23) ◽  
pp. 4485-4497 ◽  
Author(s):  
I. V. Polyakov ◽  
G. V. Alekseev ◽  
L. A. Timokhov ◽  
U. S. Bhatt ◽  
R. L. Colony ◽  
...  
Keyword(s):  
Water Temperature ◽  
Arctic Ocean ◽  
Observational Data ◽  
Low Frequency ◽  
Atlantic Water ◽  
The Arctic ◽  
Lower Latitude ◽  
Complex Nature ◽  
Temperature Record ◽  
The Arctic Ocean

Abstract Recent observations show dramatic changes of the Arctic atmosphere–ice–ocean system, including a rapid warming in the intermediate Atlantic water of the Arctic Ocean. Here it is demonstrated through the analysis of a vast collection of previously unsynthesized observational data, that over the twentieth century Atlantic water variability was dominated by low-frequency oscillations (LFO) on time scales of 50–80 yr. Associated with this variability, the Atlantic water temperature record shows two warm periods in the 1930s–40s and in recent decades and two cold periods earlier in the century and in the 1960s–70s. Over recent decades, the data show a warming and salinification of the Atlantic layer accompanied by its shoaling and, probably, thinning. The estimate of the Atlantic water temperature variability shows a general warming trend; however, over the 100-yr record there are periods (including the recent decades) with short-term trends strongly amplified by multidecadal variations. Observational data provide evidence that Atlantic water temperature, Arctic surface air temperature, and ice extent and fast ice thickness in the Siberian marginal seas display coherent LFO. The hydrographic data used support a negative feedback mechanism through which changes of density act to moderate the inflow of Atlantic water to the Arctic Ocean, consistent with the decrease of positive Atlantic water temperature anomalies in the late 1990s. The sustained Atlantic water temperature and salinity anomalies in the Arctic Ocean are associated with hydrographic anomalies of the same sign in the Greenland–Norwegian Seas and of the opposite sign in the Labrador Sea. Finally, it is found that the Arctic air–sea–ice system and the North Atlantic sea surface temperature display coherent low-frequency fluctuations. Elucidating the mechanisms behind this relationship will be critical to an understanding of the complex nature of low-frequency variability found in the Arctic and in lower-latitude regions.

Atlantic influence on content of freshwater in upper layer of the Arctic Ocean

2020 ◽  
Author(s):  
Genrikh Alekseev ◽  
Andrey Pnyushkov ◽  
Alexander Smirnov ◽  
Anastasia Vyazilova ◽  
Natalia Glok
Keyword(s):  
Barents Sea ◽  
Lower Boundary ◽  
Arctic Basin ◽  
Atlantic Water ◽  
The Arctic ◽  
Tropical Region ◽  
Close Relationship ◽  
Rfbr Grant ◽  
The 1960S ◽  
Upper Boundary

<p>The interdecadal changes in layer of the Atlantic water (AW) and the fresh water content (FWC)  in the  Arctic Basin  (AB) are traced for the 1960s - 2010s  in order to assess the influence of the influx from the Atlantic on the FWC changes. The results showed that the upper boundary of the AB layer, identified on zero isotherm, everywhere rose in the 1990s - 2010s by several tens of meters relative to its position before the start of the warming in the 1970s. The lower boundary of the layer, also determined by the depth of the zero isotherm, fell. Such displacements of the layer boundaries indicate an increase in the volume of the AW in the AB. A reduction in the volume of the upper freshened layer it is necessary to maintain balance. Our calculations confirmed that in the 1990s, the FWC in the layer 0–100 m decreased to 2 m or more in the Eurasian part of the Arctic Basin west of 180 °E and increased to east of 180 °E closer to the shores of Alaska and the Canadian archipelago,. This trend intensified in the 2000s and in the 2010s. A comparison of the distributions of the FWC and the position of the upper boundary of the AB layer over different decades by the method of spatial correlation confirmed a close relationship between both distributions. The response on changes of water temperature in the tropical region of the Atlantic is traced in the Barents Sea and in the Arctic basin.  That indicates the influence of low latitude SST on changes in AW layer and serves as an indicator of tropical effect on the Arctic processes. The study is supported by the RFBR grant 18-05-60107.</p>

scholarly journals Deglacial bottom water warming intensified Arctic methane seepage in the NW Barents Sea

2021 ◽  
Vol 2 (1) ◽  
Author(s):  
Naima El bani Altuna ◽  
Tine Lander Rasmussen ◽  
Mohamed Mahmoud Ezat ◽  
Sunil Vadakkepuliyambatta ◽  
Jeroen Groeneveld ◽  
...  
Keyword(s):  
Water Temperature ◽  
Bottom Water ◽  
Barents Sea ◽  
Ice Sheet ◽  
Atlantic Water ◽  
The Arctic ◽  
Temperature Record ◽  
Last Deglaciation ◽  
Bottom Water Temperature ◽  
Methane Seepage

AbstractChanges in the Arctic climate-ocean system can rapidly impact carbon cycling and cryosphere. Methane release from the seafloor has been widespread in the Barents Sea since the last deglaciation, being closely linked to changes in pressure and bottom water temperature. Here, we present a post-glacial bottom water temperature record (18,000–0 years before present) based on Mg/Ca in benthic foraminifera from an area where methane seepage occurs and proximal to a former Arctic ice-sheet grounding zone. Coupled ice sheet-hydrate stability modeling shows that phases of extreme bottom water temperature up to 6 °C and associated with inflow of Atlantic Water repeatedly destabilized subsurface hydrates facilitating the release of greenhouse gasses from the seabed. Furthermore, these warming events played an important role in triggering multiple collapses of the marine-based Svalbard-Barents Sea Ice Sheet. Future warming of the Atlantic Water could lead to widespread disappearance of gas hydrates and melting of the remaining marine-terminating glaciers.

scholarly journals Variability in Atlantic water temperature and transport at the entrance to the Arctic Ocean, 1997–2010

2012 ◽  
Vol 69 (5) ◽  
pp. 852-863 ◽  
Author(s):  
Agnieszka Beszczynska-Möller ◽  
Eberhard Fahrbach ◽  
Ursula Schauer ◽  
Edmond Hansen
Keyword(s):  
Water Temperature ◽  
Arctic Ocean ◽  
Seasonal Variability ◽  
Atlantic Water ◽  
Volume Transport ◽  
The Arctic ◽  
Fram Strait ◽  
Mean Temperature ◽  
The Arctic Ocean

Abstract Beszczynska-Möller, A., Fahrbach, E., Schauer, U., and Hansen, E. 2012. Variability in Atlantic water temperature and transport at the entrance to the Arctic Ocean, 1997–2010. – ICES Journal of Marine Science, 69: 852–863. The variability in Atlantic water temperature and volume transport in the West Spitsbergen Current (WSC), based on measurements by an array of moorings in Fram Strait (78°50′N) over the period 1997–2010, is addressed. The long-term mean net volume transport in the current of 6.6 ± 0.4 Sv (directed northwards) delivered 3.0 ± 0.2 Sv of Atlantic water (AW) warmer than 2°C. The mean temperature of the AW inflow was 3.1 ± 0.1°C. On interannual time-scales, a nearly constant volume flux in the WSC core (long-term mean 1.8 ± 0.1 Sv northwards, including 1.3 ± 0.1 Sv of AW warmer than 2°C, and showing no seasonal variability) was accompanied by a highly variable transport of 2–6 Sv in the offshore branch (long-term mean of 5 ± 0.4 Sv, strong seasonal variability, and 1–2 Sv of warm AW). Two warm anomalies were found in the AW passing through Fram Strait in 1999–2000 and 2005–2007. For the period 1997–2010, there was a positive linear trend in the AW mean temperature of 0.06°C year−1, but no statistically significant trend was observed in the AW volume transport. A possible impact of warming on AW propagation in the Arctic Ocean and properties of the outflow to the North Atlantic are also discussed.

Boundary current heat loss and mixing processes at the Arctic Ocean continental margin

2021 ◽  
Author(s):  
Kirstin Schulz ◽  
Markus Janout ◽  
Yueng-Djern Lenn ◽  
Eugenio Ruiz-Castillo ◽  
Igor Polyakov ◽  
...  
Keyword(s):  
Sea Ice ◽  
Heat Loss ◽  
Barents Sea ◽  
Arctic Basin ◽  
Water Layer ◽  
Bottom Layer ◽  
Atlantic Water ◽  
The Arctic ◽  
Mixing Processes ◽  
Boundary Mixing

<p>Inflowing Atlantic Water forms a significant heat reservoir in the Arctic Ocean. In the Barents Sea, where the Atlantic Water layer resides close to the surface, strong upward heat fluxes reduce the sea ice cover. Along with a warming climate, an eastward progression of these conditions typical for the Barents Sea is anticipated. These new conditions have the potential to cause dramatic regime shifts in the Laptev Sea region, where the sea ice and the oceanic surface layer are currently sheltered from the warm Atlantic Water by a permanent halocline. Understanding and quantifying the dominant mixing processes in the Siberian Seas is hence crucial to predict how mixing and sea ice conditions, as well as particle and nutrient transport pathways will evolve in the future.</p><p>Based on recent temperature and current velocity profiles from this region, we quantify the Atlantic Water heat loss along its pathway around the Arctic basin margins. Contemporaneous turbulent microstructure measurement reveal that only 20% of this heat loss takes place in the deep basin, emphasizing the important role of stronger mixing in the continental slope region. Observed boundary mixing processes include:</p><ul><li> <p>Mixing in the frictional near bottom layer, strongly enhanced at the lee side of a topographic features and where large temperature gradients associated with the upper bound of the Atlantic Water layer are present in the turbulent near bottom layer.</p> </li> <li> <p>Spatially confined but energetic mixing events over the whole water column. These events are ephemeral but re-occurring and can homogenize the intermediate water column down to a depth of over 300m, with substantial implications for heat transport, the vertical distribution of nutrients and cross-slope particle transport.</p> </li> </ul><p>The presented results provide new insights into the complex mixing and transport patterns at the Arctic basin margins, and further emphasize the importance of boundary mixing across disciplines.</p>

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