The anatomy of the Arctic Frontal Zone in the Greenland Sea

1995 ◽  
Vol 100 (C8) ◽  
pp. 15999 ◽  
Author(s):  
Hendrik M. van Aken ◽  
Gereon Budéus ◽  
Michael Hähnel
Keyword(s):  
Frontal Zone ◽  
The Arctic ◽  
Greenland Sea

scholarly journals Sea ice volume variability and water temperature in the Greenland Sea

2020 ◽  
Vol 14 (2) ◽  
pp. 477-495 ◽  
Author(s):  
Valeria Selyuzhenok ◽  
Igor Bashmachnikov ◽  
Robert Ricker ◽  
Anna Vesman ◽  
Leonid Bobylev
Keyword(s):  
Sea Ice ◽  
North Atlantic ◽  
Heat Content ◽  
The Arctic ◽  
Fram Strait ◽  
Greenland Sea ◽  
Nordic Seas ◽  
Ice Volume ◽  
Long Term Variations

Abstract. This study explores a link between the long-term variations in the integral sea ice volume (SIV) in the Greenland Sea and oceanic processes. Using the Pan-Arctic Ice Ocean Modeling and Assimilation System (PIOMAS, 1979–2016), we show that the increasing sea ice volume flux through Fram Strait goes in parallel with a decrease in SIV in the Greenland Sea. The overall SIV loss in the Greenland Sea is 113 km3 per decade, while the total SIV import through Fram Strait increases by 115 km3 per decade. An analysis of the ocean temperature and the mixed-layer depth (MLD) over the climatic mean area of the winter marginal sea ice zone (MIZ) revealed a doubling of the amount of the upper-ocean heat content available for the sea ice melt from 1993 to 2016. This increase alone can explain the SIV loss in the Greenland Sea over the 24-year study period, even when accounting for the increasing SIV flux from the Arctic. The increase in the oceanic heat content is found to be linked to an increase in temperature of the Atlantic Water along the main currents of the Nordic Seas, following an increase in the oceanic heat flux from the subtropical North Atlantic. We argue that the predominantly positive winter North Atlantic Oscillation (NAO) index during the 4 most recent decades, together with an intensification of the deep convection in the Greenland Sea, is responsible for the intensification of the cyclonic circulation pattern in the Nordic Seas, which results in the observed long-term variations in the SIV.

Acoustic propagation in the western Greenland Sea frontal zone

1991 ◽  
Vol 89 (5) ◽  
pp. 2144-2156 ◽  
Author(s):  
Leonard E. Mellberg ◽  
Ola M. Johannessen ◽  
Donald N. Connors ◽  
George Botseas ◽  
David G. Browning
Keyword(s):  
Frontal Zone ◽  
Acoustic Propagation ◽  
Greenland Sea

Reproduction of the Arctic copepod Calanus hyperboreus in the Greenland Sea-field and laboratory observations

Polar Biology ◽  
1996 ◽  
Vol 16 (3) ◽  
pp. 209-219 ◽  
Author(s):  
Hans-Jürgen Hirche ◽  
Barbara Niehoff
Keyword(s):  
The Arctic ◽  
Greenland Sea ◽  
Calanus Hyperboreus

Relationships linking satellite-retrieved ocean color data with atmospheric components in the Arctic

2020 ◽  
Author(s):  
Marjan Marbouti ◽  
Sehyun Jang ◽  
Silvia Becagli ◽  
Tuomo Nieminen ◽  
Gabriel Navarro ◽  
...  
Keyword(s):  
Sea Ice ◽  
Barents Sea ◽  
Ocean Color ◽  
Particle Formation ◽  
The Arctic ◽  
Ice Melting ◽  
New Particle Formation ◽  
Greenland Sea ◽  
Chl A ◽  
Color Data

<p>We examined the relationships linking in-situ measurements of gas-phase methanesulfonic acid (MSA), sulfuric acid (SA), iodic acid (HIO3), Highly Oxidized Organic Molecules (HOM) and aerosol size-distributions with satellite-derived chlorophyll (Chl-a) and oceanic primary production (PP). Atmospheric data were collected at Ny-Ålesund site during spring-summer 2017 (30th March-4th August). We compared ocean color data from Barents Sea and Greenland Sea with concentrations of low-volatile vapours and new particle formation. The aim is to understand the main factors controlling the concentrations of atmospheric components in the Arctic in different ocean domains and seasons. Early phytoplanktonic bloom starting in April at the marginal ice zone caused Chl-a and PP in the Barents Sea to be higher than in the Greenland Sea during spring, whereas the pattern was opposite in summer. We found the correlation between ocean color data (Chl-a and PP) and MSA decreasing from spring to summer in Barents Sea and increasing in Greenland Sea. This establishes relationship between sea ice melting and phytoplanktonic bloom, which starts by sea ice melting. Similar pattern was observed for SA. Also HIO3 in both ocean domains correlated with Chl-a and PP during spring time. Greenland Sea was more active than Barents Sea. These results suggest that marine phytoplankton metabolism is an important source of MSA and SA, as expected, but also a source of HIO3 precursors (such as I2). HOMs had low correlation with ocean color parameters in comparison to other atmospheric vapours in this study both in spring and summer. The plausible explanation for low correlation is that the primary source of Volatile Organic Compounds (VOC) – precursors of HOM – is the soil of Svalbard archipelago rather than ocean. During spring, nucleation mode particles were found to correlate with Chl-a at Barents Sea and with PP at Greenland Sea. This means that biogenic productivity has a strong impact on new particle formation in spring although small particles are not related to biogenic parameters in summer.</p>

Reproduction of the Arctic copepodCalanus hyperboreus in the Greenland Sea-field and laboratory observations

Polar Biology ◽  
1996 ◽  
Vol 16 (3) ◽  
pp. 209-219 ◽  
Author(s):  
Hans-Jürgen Hirche ◽  
Barbara Niehoff
Keyword(s):  
The Arctic ◽  
Greenland Sea

scholarly journals Comparison of acoustical and optical zooplankton measurements using an acoustic scattering model: A case study from the Arctic frontal zone

2016 ◽  
Vol 37 (1) ◽  
pp. 67-88 ◽  
Author(s):  
Joanna Szczucka ◽  
Emilia Trudnowska ◽  
Łukasz Hoppe ◽  
Katarzyna Błachowiak-Samołyk
Keyword(s):  
Frontal Zone ◽  
Acoustic Scattering ◽  
Water Layer ◽  
The Arctic ◽  
Zooplankton Abundance ◽  
Sound Scattering ◽  
Distribution Studies ◽  
West Spitsbergen ◽  
High Pass

Abstract High-frequency acoustic measurements supplemented by a modern optical method, Laser Optical Plankton Counter (LOPC), allowed us to perform a comparative analysis through the application of a mathematical model. We have studied the correspondence between measured and modelled echoes from zooplankton aggregations consisted mainly of two Calanus species. Data were collected from the upper 50 m water layer within the hydrographical frontal zone on the West Spitsbergen Shelf. The application of a “high-pass” model of sound scattering by fluid-like particles to the distribution of zooplankton sizes measured by LOPC resulted mostly in very good agreement between the measured (420 kHz BioSonics) and modelled values, except for cases with very low zooplankton abundance or with occurrence of stronger scatterers (e.g. macrozooplankton, fish). An acoustic model validated for the elastic parameters of zooplankton confirmed that particles smaller than 1mmin diameter, although highly abundant, did not contribute significantly to the sound scattering process at a frequency of 420 kHz. The implementation of diverse complementary methods has great potential to obtain high spatial and temporal resolution in zooplankton distribution studies; however, their compatibility has to be tested first.

scholarly journals Soundscape and ambient noise levels of the Arctic waters around Greenland

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michael Ladegaard ◽  
Jamie Macauley ◽  
Malene Simon ◽  
Kristin L. Laidre ◽  
Aleksandrina Mitseva ◽  
...  
Keyword(s):  
Ambient Noise ◽  
Anthropogenic Activities ◽  
Open Water ◽  
Anthropogenic Sources ◽  
The Arctic ◽  
Underwater Noise ◽  
Noise Levels ◽  
Greenland Sea ◽  
Mammal Species ◽  
Seismic Surveys

AbstractA longer Arctic open water season is expected to increase underwater noise levels due to anthropogenic activities such as shipping, seismic surveys, sonar, and construction. Many Arctic marine mammal species depend on sound for communication, navigation, and foraging, therefore quantifying underwater noise levels is critical for documenting change and providing input to management and legislation. Here we present long-term underwater sound recordings from 26 deployments around Greenland from 2011 to 2020. Ambient noise was analysed in third octave and decade bands and further investigated using generic detectors searching for tonal and transient sounds. Ambient noise levels partly overlap with previous Arctic observations, however we report much lower noise levels than previously documented, specifically for Melville Bay and the Greenland Sea. Consistent seasonal noise patterns occur in Melville Bay, Baffin Bay and Greenland Sea, with noise levels peaking in late summer and autumn correlating with open water periods and seismic surveys. These three regions also had similar tonal detection patterns that peaked in May/June, likely due to bearded seal vocalisations. Biological activity was more readily identified using detectors rather than band levels. We encourage additional research to quantify proportional noise contributions from geophysical, biological, and anthropogenic sources in Arctic waters.

scholarly journals Role of cabbeling in water densification in the Greenland Basin

Ocean Science ◽  
2009 ◽  
Vol 5 (3) ◽  
pp. 247-257 ◽  
Author(s):  
Y. Kasajima ◽  
T. Johannessen
Keyword(s):  
Barents Sea ◽  
Water Mass ◽  
Cold Water ◽  
Maximum Velocity ◽  
The Arctic ◽  
Intermediate Water ◽  
Greenland Sea ◽  
Velocity Magnitude ◽  
Basin Scale ◽  
Greenland Basin

Abstract. The effects of cabbeling mixing on water mass modification in the Greenland Sea were explored by hydrographic observations across the Greenland Basin in summer 2006. The neutral surface was chosen as a reference frame, and the strength of cabbeling mixing was quantified by the dianeutral velocity magnitude. Active cabbeling spots were detected with the criterion of the velocity magnitude >1 m/day, and four active cabbeling areas were identified; the west of Bear Island (SB), the Arctic Frontal Zone (AFZ), the central Greenland Sea (CG) and the western Greenland Sea (WG). The most vigorous cabbeling mixing was found at SB, where warm North Atlantic Water (NAW) mixed with cold water from the Barents Sea, inducing a maximum velocity of 7.5 m/day and a maximum density gain of 4.7×10−3 kg/m3. At AFZ and CG, the mixing took place between NAW, modified NAW and Arctic Intermediate Water (AIW), and the density gain at these fronts were 1.5×10−3 kg/m3 (AFZ) and 1.3×10−3 kg/m3 (CG). In the western Greenland Sea, the active cabbeling spots were widely separated and mixing appeared to be rather weak, with a maximum velocity of 2.5 m/day. The mixing source waters at WG were modified NAW, AIW and even denser water, and the density gain in this area was 0.4×10−3 kg/m3. The deepest mixing produced water whose density is equivalent to that of the dense water of the basin, indicating that cabbeling in the western Greenland Sea contributed directly to basin-scale water densification. The water mass modification rate was the highest at AFZ (about 8.0 Sv), suggesting that cabbeling may play an important role in water transformation in the Greenland Basin.

scholarly journals Does the Summer Arctic Frontal Zone Influence Arctic Ocean Cyclone Activity?

2016 ◽  
Vol 29 (13) ◽  
pp. 4977-4993 ◽  
Author(s):  
Alex D. Crawford ◽  
Mark C. Serreze
Keyword(s):  
Arctic Ocean ◽  
Large Scale ◽  
Frontal Zone ◽  
External Source ◽  
The Arctic ◽  
Cyclone Activity ◽  
Central Arctic Ocean ◽  
The Arctic Ocean ◽  
Summer Maximum ◽  
Horizontal Temperature Gradients

Abstract Extratropical cyclone activity over the central Arctic Ocean reaches its peak in summer. Previous research has argued for the existence of two external source regions for cyclones contributing to this summer maximum: the Eurasian continent interior and a narrow band of strong horizontal temperature gradients along the Arctic coastline known as the Arctic frontal zone (AFZ). This study incorporates data from an atmospheric reanalysis and an advanced cyclone detection and tracking algorithm to critically evaluate the relationship between the summer AFZ and cyclone activity in the central Arctic Ocean. Analysis of both individual cyclone tracks and seasonal fields of cyclone characteristics shows that the Arctic coast (and therefore the AFZ) is not a region of cyclogenesis. Rather, the AFZ acts as an intensification area for systems forming over Eurasia. As these systems migrate toward the Arctic Ocean, they experience greater deepening in situations when the AFZ is strong at midtropospheric levels. On a broader scale, intensity of the summer AFZ at midtropospheric levels has a positive correlation with cyclone intensity in the Arctic Ocean during summer, even when controlling for variability in the northern annular mode. Taken as a whole, these findings suggest that the summer AFZ can intensify cyclones that cross the coast into the Arctic Ocean, but focused modeling studies are needed to disentangle the relative importance of the AFZ, large-scale circulation patterns, and topographic controls.

Sign in / Sign up

Export Citation Format

Share Document