scholarly journals The Greenland Sea Jet: A mechanism for wind-driven sea ice export through Fram Strait

2011 ◽  
Vol 38 (12) ◽  
pp. n/a-n/a ◽  
Author(s):  
J. H. van Angelen ◽  
M. R. van den Broeke ◽  
R. Kwok
Keyword(s):  
Sea Ice ◽  
2020 ◽  
Vol 14 (2) ◽  
pp. 477-495 ◽  
Author(s):  
Valeria Selyuzhenok ◽  
Igor Bashmachnikov ◽  
Robert Ricker ◽  
Anna Vesman ◽  
Leonid Bobylev

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.


2019 ◽  
Author(s):  
Valeria Selyuzhenok ◽  
Igor Bashmachnikov ◽  
Robert Ricker ◽  
Anna Vesman ◽  
Leonid Bobylev

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 Pan-Arctic Ice Ocean Modelling and Assimilation System (PIOMAS, 1979–2016), we show that the negative tendencies in SIV go in parallel with the increasing ice flux through the Fram Strait. The overall SIV loss in the Greenland Sea comprises 113 km3 per decade, while the total SIV import through the Fram strait is increasing by 115 km3 per decade. An analysis of the ocean temperature and the mixed layer depth (MLD) in the marginal sea ice zone (MIZ), based on ARMOR data-set (1993–2016), revealed doubling of the amount of the upper ocean heat content available for the ice melt in the MIZ. This increase over the 24-year period can solely explain the SIV loss in the Greenland Sea, even when accounting for the increasing SIV flux from the Arctic. The increase in the ocean heat content is found to be linked to an increase in the temperature of the Atlantic water in the Nordic seas, following an increase of ocean heat flux form the subtropical North Atlantic. We argue that the predominantly positive North Atlantic Oscillation (NAO) index during the four recent decades, together with the intensification of the deep convection in the Greenland Sea, are responsible for the overall intensification of the circulation in the Nordic seas, which explains the observed long-term variations of the SIV.


Polar Record ◽  
1983 ◽  
Vol 21 (135) ◽  
pp. 597-600
Author(s):  
Torgny Vinje ◽  
Monica Kristensen ◽  
Niels Nergaard

2006 ◽  
Vol 44 ◽  
pp. 30-36 ◽  
Author(s):  
Stefan Kern ◽  
Youmin Chen ◽  
Detlef Stammer ◽  
Gunnar Spreen

AbstractAnnual and winter (December–April) sea-ice area and extent are calculated for the Greenland Sea (GS) and Barents Sea (BS) from daily ice concentrations obtained from space-borne microwave radiometry for 1979–2003. The ice extent decreases significantly, particularly during winter, by 65 000 km2 (decade)–1 in the GS and by 72 000 km2 (decade)–1 in the BS. Ice-extent fractions (of these total extents) occupied by ice of five different ice-concentration ranges are calculated and analyzed. Changes in these fractions are again significant and most pronounced during winter. In the GS, the fraction of close to very compact ice (65–95%) decreases by 17 000 km2 (decade)–1 and the fraction of very compact ice (>95%) increases by 29 000 km2 (decade)–1, corresponding to a loss of 19% and a gain of 58% relative to the 25 year mean, respectively. In the BS, the fraction of close to compact ice (65–85%) increases by 26 000km2 (decade)–1 and the fraction with compact to very compact ice (>85%) decreases by 66 000 km2 (decade)–1, corresponding to a gain of 30% and a loss of 67% relative to the 25 year mean, respectively. The changing surface wind pattern analyzed from ERA-40 data favours this increasing (decreasing) ice compactness in the GS (BS).


2011 ◽  
Vol 5 (3) ◽  
pp. 1311-1334 ◽  
Author(s):  
L. H. Smedsrud ◽  
A. Sirevaag ◽  
K. Kloster ◽  
A. Sorteberg ◽  
S. Sandven

Abstract. Arctic sea ice area decrease has been visible for two decades, and continues at a steady rate. Apart from melting, the southward drift through Fram Strait is the main loss. We present high resolution sea ice drift across 79&deg N from 2004 to 2010. The ice drift is based on radar satellite data and correspond well with variability in local geostrophic wind. The underlying current contributes with a constant southward speed close to 5 cm s−1, and drives about 33 % of the ice export. We use geostrophic winds derived from reanalysis data to calculate the Fram Strait ice area export back to 1957, finding that the sea ice area export recently is about 25 % larger than during the 1960's. The increase in ice export occurred mostly during winter and is directly connected to higher southward ice drift velocities, due to stronger geostrophic winds. The increase in ice drift is large enough to counteract a decrease in ice concentration of the exported sea ice. Using storm tracking we link changes in geostrophic winds to more intense Nordic Sea low pressure systems. Annual sea ice export likely has a significant influence on the summer sea ice variability and we find low values in the 60's, the late 80's and 90's, and particularly high values during 2005–2008. The study highlight the possible role of variability in ice export as an explanatory factor for understanding the dramatic loss of Arctic sea ice the last decades.


Ocean Science ◽  
2020 ◽  
Vol 16 (5) ◽  
pp. 1017-1032
Author(s):  
Heike H. Zimmermann ◽  
Kathleen R. Stoof-Leichsenring ◽  
Stefan Kruse ◽  
Juliane Müller ◽  
Ruediger Stein ◽  
...  

Abstract. The Fram Strait is an area with a relatively low and irregular distribution of diatom microfossils in surface sediments, and thus microfossil records are scarce, rarely exceed the Holocene, and contain sparse information about past richness and taxonomic composition. These attributes make the Fram Strait an ideal study site to test the utility of sedimentary ancient DNA (sedaDNA) metabarcoding. Amplifying a short, partial rbcL marker from samples of sediment core MSM05/5-712-2 resulted in 95.7 % of our sequences being assigned to diatoms across 18 different families, with 38.6 % of them being resolved to species and 25.8 % to genus level. Independent replicates show a high similarity of PCR products, especially in the oldest samples. Diatom sedaDNA richness is highest in the Late Weichselian and lowest in Mid- and Late Holocene samples. Taxonomic composition is dominated by cold-water and sea-ice-associated diatoms and suggests several reorganisations – after the Last Glacial Maximum, after the Younger Dryas, and after the Early and after the Mid-Holocene. Different sequences assigned to, amongst others, Chaetoceros socialis indicate the detectability of intra-specific diversity using sedaDNA. We detect no clear pattern between our diatom sedaDNA record and the previously published IP25 record of this core, although proportions of pennate diatoms increase with higher IP25 concentrations and proportions of Nitzschia cf. frigida exceeding 2 % of the assemblage point towards past sea-ice presence.


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