scholarly journals Influence of the Gulf Stream on the Barents Sea ice retreat and Eurasian coldness during early winter

2014 ◽  
Vol 9 (8) ◽  
pp. 084009 ◽  
Author(s):  
Kazutoshi Sato ◽  
Jun Inoue ◽  
Masahiro Watanabe
Keyword(s):  
Sea Ice ◽  
Gulf Stream ◽  
Barents Sea ◽  
Early Winter ◽  
The Barents Sea ◽  
Ice Retreat ◽  
Sea Ice Retreat

Quantifying the Influence of Atlantic Heat on Barents Sea Ice Variability and Retreat*

2012 ◽  
Vol 25 (13) ◽  
pp. 4736-4743 ◽  
Author(s):  
M. Årthun ◽  
T. Eldevik ◽  
L. H. Smedsrud ◽  
Ø. Skagseth ◽  
R. B. Ingvaldsen
Keyword(s):  
Sea Ice ◽  
Heat Transport ◽  
Barents Sea ◽  
Heat Budget ◽  
Heat Content ◽  
Ocean Model ◽  
Sea Ice Extent ◽  
The Barents Sea ◽  
Ice Retreat ◽  
Sea Ice Retreat

Abstract The recent Arctic winter sea ice retreat is most pronounced in the Barents Sea. Using available observations of the Atlantic inflow to the Barents Sea and results from a regional ice–ocean model the authors assess and quantify the role of inflowing heat anomalies on sea ice variability. The interannual variability and longer-term decrease in sea ice area reflect the variability of the Atlantic inflow, both in observations and model simulations. During the last decade (1998–2008) the reduction in annual (July–June) sea ice area was 218 × 103 km2, or close to 50%. This reduction has occurred concurrent with an increase in observed Atlantic heat transport due to both strengthening and warming of the inflow. Modeled interannual variations in sea ice area between 1948 and 2007 are associated with anomalous heat transport (r = −0.63) with a 70 × 103 km2 decrease per 10 TW input of heat. Based on the simulated ocean heat budget it is found that the heat transport into the western Barents Sea sets the boundary of the ice-free Atlantic domain and, hence, the sea ice extent. The regional heat content and heat loss to the atmosphere scale with the area of open ocean as a consequence. Recent sea ice loss is thus largely caused by an increasing “Atlantification” of the Barents Sea.

Associations among temperature, sea ice and phytoplankton bloom dynamics in the Barents Sea

2020 ◽  
Vol 635 ◽  
pp. 25-36 ◽  
Author(s):  
K Dong ◽  
ØK Kvile ◽  
NC Stenseth ◽  
LC Stige
Keyword(s):  
Sea Ice ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
Barents Sea ◽  
Phytoplankton Bloom ◽  
Sea Surface ◽  
The Barents Sea ◽  
Ice Retreat ◽  
Sea Ice Retreat ◽  
Time Substitution

Variations in physical conditions caused by climate change are likely to have large influences on marine organisms, including phytoplankton. Here, we investigated associations between satellite-derived chlorophyll a data from the Barents Sea and 2 key abiotic factors: sea surface temperature and sea-ice concentration. Specifically, we investigated how climate variability, through the measured physical factors, associated with phytoplankton phenology between 1998 and 2014. Associations between sea surface temperature and phytoplankton bloom dynamics differed depending on the area. The spring phytoplankton bloom occurred earlier and had higher magnitude in warm compared to cold years in the northern part of the Barents Sea, but there was no significant association in the southern part. In seasonally ice-covered regions, the association between the timing of the sea-ice retreat and the phytoplankton peak was nonlinear: sea-ice retreat time before mid-May was not associated with bloom timing, whereas the phytoplankton bloom occurred before or immediately following the ice retreat when the ice retreated after mid-May. Although drivers that are relatively constant across years, such as insolation, probably influenced the spatial gradient in chlorophyll, a space-for-time substitution captured the predicted effects of sea-ice retreat on the timing and magnitude of the phytoplankton bloom quite well.

scholarly journals Sea-ice indicators of polar bear habitat

2016 ◽  
Vol 10 (5) ◽  
pp. 2027-2041 ◽  
Author(s):  
Harry L. Stern ◽  
Kristin L. Laidre
Keyword(s):  
Sea Ice ◽  
Polar Bear ◽  
Barents Sea ◽  
Arctic Basin ◽  
Concentration Data ◽  
Sea Ice Concentration ◽  
The Barents Sea ◽  
Ice Concentration ◽  
Ice Retreat ◽  
Sea Ice Retreat

Abstract. Nineteen subpopulations of polar bears (Ursus maritimus) are found throughout the circumpolar Arctic, and in all regions they depend on sea ice as a platform for traveling, hunting, and breeding. Therefore polar bear phenology – the cycle of biological events – is linked to the timing of sea-ice retreat in spring and advance in fall. We analyzed the dates of sea-ice retreat and advance in all 19 polar bear subpopulation regions from 1979 to 2014, using daily sea-ice concentration data from satellite passive microwave instruments. We define the dates of sea-ice retreat and advance in a region as the dates when the area of sea ice drops below a certain threshold (retreat) on its way to the summer minimum or rises above the threshold (advance) on its way to the winter maximum. The threshold is chosen to be halfway between the historical (1979–2014) mean September and mean March sea-ice areas. In all 19 regions there is a trend toward earlier sea-ice retreat and later sea-ice advance. Trends generally range from −3 to −9 days decade−1 in spring and from +3 to +9 days decade−1 in fall, with larger trends in the Barents Sea and central Arctic Basin. The trends are not sensitive to the threshold. We also calculated the number of days per year that the sea-ice area exceeded the threshold (termed ice-covered days) and the average sea-ice concentration from 1 June through 31 October. The number of ice-covered days is declining in all regions at the rate of −7 to −19 days decade−1, with larger trends in the Barents Sea and central Arctic Basin. The June–October sea-ice concentration is declining in all regions at rates ranging from −1 to −9 percent decade−1. These sea-ice metrics (or indicators of habitat change) were designed to be useful for management agencies and for comparative purposes among subpopulations. We recommend that the National Climate Assessment include the timing of sea-ice retreat and advance in future reports.

scholarly journals Sea-Ice Indicators of Polar Bear Habitat

2016 ◽  
Author(s):  
Harry L. Stern ◽  
Kristin L. Laidre
Keyword(s):  
Sea Ice ◽  
Polar Bear ◽  
Barents Sea ◽  
Arctic Basin ◽  
The Arctic ◽  
Sea Ice Concentration ◽  
The Barents Sea ◽  
Ice Concentration ◽  
Ice Retreat ◽  
Sea Ice Retreat

Abstract. Abstract. Nineteen distinct subpopulations of polar bears (Ursus maritimus) are found throughout the Arctic, and in all regions they depend on sea ice as a platform for traveling, hunting, and breeding. Therefore polar bear phenology – the cycle of biological events – is tied to the timing of sea-ice retreat in spring and advance in fall. We analyzed the dates of sea-ice retreat and advance in all 19 polar bear subpopulation regions from 1979 to 2014, using daily sea-ice concentration data from satellite passive microwave instruments. We define the dates of sea-ice retreat and advance in a region as the dates when the area of sea ice drops below a certain threshold (retreat) on its way to the summer minimum, or rises above the threshold (advance) on its way to the winter maximum. The threshold is chosen to be halfway between the historical (1979–2014) mean September and mean March sea-ice areas. In all 19 regions there is a trend toward earlier sea-ice retreat and later sea-ice advance. Trends generally range from −3 to −9 days decade−1 in spring, and from +3 to +9 days decade−1 in fall, with larger trends in the Barents Sea and central Arctic Basin. The trends are not sensitive to the threshold. We also calculated the number of days per year that the sea-ice area exceeded the threshold (termed ice-covered days), and the average sea-ice concentration from 1 June through 31 October. The number of ice-covered days is declining in all regions at the rate of −7 to −19 days decade−1, with larger trends in the Barents Sea and central Arctic Basin. The June–October sea-ice concentration is declining in all regions at rates ranging from −1 to −9 percent decade−1. These sea-ice metrics (or indicators of change in marine mammal habitat) were designed to be useful for management agencies. We recommend that the National Climate Assessment include the timing of sea-ice retreat and advance in future reports.

scholarly journals Predictability of the Barents Sea Ice in Early Winter: Remote Effects of Oceanic and Atmospheric Thermal Conditions from the North Atlantic

2014 ◽  
Vol 27 (23) ◽  
pp. 8884-8901 ◽  
Author(s):  
Takuya Nakanowatari ◽  
Kazutoshi Sato ◽  
Jun Inoue
Keyword(s):  
Sea Ice ◽  
North Atlantic ◽  
Barents Sea ◽  
Temperature Anomaly ◽  
Early Winter ◽  
Subsurface Temperature ◽  
The North ◽  
The Barents Sea ◽  
Subsurface Temperature Anomaly ◽  
The North Atlantic

Abstract Predictability of sea ice concentrations (SICs) in the Barents Sea in early winter (November–December) is studied using canonical correlation analysis with atmospheric and ocean anomalies from the NCEP Climate Forecast System Reanalysis (CFSR) data. It is found that the highest prediction skill for a single-predictor model is obtained from the 13-month lead subsurface temperature at 200-m depth (T200) and the in-phase meridional surface wind (Vsfc). T200 skillfully predicts SIC variability in 35% of the Barents Sea, mainly in the eastern side. The T200 for negative sea ice anomalies exhibits warm anomalies in the subsurface ocean temperature downstream of the Norwegian Atlantic Slope Current (NwASC) on a decadal time scale. The diagnostic analysis of NCEP CFSR data suggests that the subsurface temperature anomaly stored below the thermocline during summer reemerges in late autumn by atmospheric cooling and affects the sea ice. The subsurface temperature anomaly of the NwASC is advected from the North Atlantic subpolar gyre over ~3 years. Also, Vsfc skillfully predicts SIC variability in 32% of the Barents Sea, mainly in the western side. The Vsfc for the negative sea ice anomalies exhibits southerly wind anomalies; Vsfc is related to the large-scale atmospheric circulation patterns from the subtropical North Atlantic to the Eurasian continent. This study suggests that both atmospheric and oceanic remote effects have a potential impact on the forecasting accuracy of SIC.

Arctic Freshwater in CMIP6: Declining Sea Ice, Increasing Ocean Storage and Export

2021 ◽  
Author(s):  
Hannah Zanowski ◽  
Alexandra Jahn ◽  
Marika Holland
Keyword(s):  
Sea Ice ◽  
21St Century ◽  
Barents Sea ◽  
The Arctic ◽  
Historical Period ◽  
Freshwater Flux ◽  
Bering Strait ◽  
The Barents Sea ◽  
Late 21St Century ◽  
Freshwater Export

<p>Recently, the Arctic has undergone substantial changes in sea ice cover and the hydrologic cycle, both of which strongly impact the freshwater storage in, and export from, the Arctic Ocean. Here we analyze Arctic freshwater storage and fluxes in 7 climate models from the Coupled Model Intercomparison Project phase 6 (CMIP6) and assess their agreement over the historical period (1980-2000) and in two future emissions scenarios, SSP1-2.6 and SSP5-8.5. In the historical simulation, few models agree closely with observations over 1980-2000. In both future scenarios the models show an increase in liquid (ocean) freshwater storage in conjunction with a reduction in solid storage and fluxes through the major Arctic gateways (Bering Strait, Fram Strait, Davis Strait, and the Barents Sea Opening) that is typically larger for SSP5-8.5 than SSP1-2.6. The liquid fluxes through the gateways exhibit a more complex pattern, with models exhibiting a change in sign of the freshwater flux through the Barents Sea Opening and little change in the flux through the Bering Strait in addition to increased export from the remaining straits by the end of the 21st century. A decomposition of the liquid fluxes into their salinity and volume contributions shows that the Barents Sea flux changes are driven by salinity changes, while the Bering Strait flux changes are driven by compensating salinity and volume changes. In the straits west of Greenland (Nares, Barrow, and Davis straits), the models disagree on whether there will be a decrease, increase, or steady liquid freshwater export in the early to mid 21st century, although they mostly show increased liquid freshwater export in the late 21st century. The underlying cause of this is a difference in the magnitude and timing of a simulated decrease in the volume flux through these straits. Although the models broadly agree on the sign of late 21st century storage and flux changes, substantial differences exist between the magnitude of these changes and the models’ Arctic mean states, which shows no fundamental improvement in the models compared to CMIP5.</p>

scholarly journals Climate change impacts on sea–air fluxes of CO<sub>2</sub> in three Arctic seas: a sensitivity study using Earth observation

2013 ◽  
Vol 10 (12) ◽  
pp. 8109-8128 ◽  
Author(s):  
P. E. Land ◽  
J. D. Shutler ◽  
R. D. Cowling ◽  
D. K. Woolf ◽  
P. Walker ◽  
...  
Keyword(s):  
Climate Change ◽  
Sea Ice ◽  
Barents Sea ◽  
Earth Observation ◽  
Kara Sea ◽  
Sink Strength ◽  
Arctic Seas ◽  
The Barents Sea ◽  
Co2 Sink ◽  
Positive Effect

Abstract. We applied coincident Earth observation data collected during 2008 and 2009 from multiple sensors (RA2, AATSR and MERIS, mounted on the European Space Agency satellite Envisat) to characterise environmental conditions and integrated sea–air fluxes of CO2 in three Arctic seas (Greenland, Barents, Kara). We assessed net CO2 sink sensitivity due to changes in temperature, salinity and sea ice duration arising from future climate scenarios. During the study period the Greenland and Barents seas were net sinks for atmospheric CO2, with integrated sea–air fluxes of −36 ± 14 and −11 ± 5 Tg C yr−1, respectively, and the Kara Sea was a weak net CO2 source with an integrated sea–air flux of +2.2 ± 1.4 Tg C yr−1. The combined integrated CO2 sea–air flux from all three was −45 ± 18 Tg C yr−1. In a sensitivity analysis we varied temperature, salinity and sea ice duration. Variations in temperature and salinity led to modification of the transfer velocity, solubility and partial pressure of CO2 taking into account the resultant variations in alkalinity and dissolved organic carbon (DOC). Our results showed that warming had a strong positive effect on the annual integrated sea–air flux of CO2 (i.e. reducing the sink), freshening had a strong negative effect and reduced sea ice duration had a small but measurable positive effect. In the climate change scenario examined, the effects of warming in just over a decade of climate change up to 2020 outweighed the combined effects of freshening and reduced sea ice duration. Collectively these effects gave an integrated sea–air flux change of +4.0 Tg C in the Greenland Sea, +6.0 Tg C in the Barents Sea and +1.7 Tg C in the Kara Sea, reducing the Greenland and Barents sinks by 11% and 53%, respectively, and increasing the weak Kara Sea source by 81%. Overall, the regional integrated flux changed by +11.7 Tg C, which is a 26% reduction in the regional sink. In terms of CO2 sink strength, we conclude that the Barents Sea is the most susceptible of the three regions to the climate changes examined. Our results imply that the region will cease to be a net CO2 sink in the 2050s.

scholarly journals Timing of sea ice retreat can alter phytoplankton community structure in the western Arctic Ocean

2014 ◽  
Vol 11 (7) ◽  
pp. 1705-1716 ◽  
Author(s):  
A. Fujiwara ◽  
T. Hirawake ◽  
K. Suzuki ◽  
I. Imai ◽  
S.-I. Saitoh
Keyword(s):  
Community Structure ◽  
Sea Ice ◽  
Arctic Ocean ◽  
Phytoplankton Community ◽  
Phytoplankton Community Structure ◽  
Western Arctic Ocean ◽  
Phytoplankton Communities ◽  
Ice Retreat ◽  
Western Arctic ◽  
Sea Ice Retreat

Abstract. This study assesses the response of phytoplankton assemblages to recent climate change, especially with regard to the shrinking of sea ice in the northern Chukchi Sea of the western Arctic Ocean. Distribution patterns of phytoplankton groups in the late summers of 2008–2010 were analysed based on HPLC pigment signatures and, the following four major algal groups were inferred via multiple regression and cluster analyses: prasinophytes, diatoms, haptophytes and dinoflagellates. A remarkable interannual difference in the distribution pattern of the groups was found in the northern basin area. Haptophytes dominated and dispersed widely in warm surface waters in 2008, whereas prasinophytes dominated in cold water in 2009 and 2010. A difference in the onset date of sea ice retreat was evident among years–the sea ice retreat in 2008 was 1–2 months earlier than in 2009 and 2010. The spatial distribution of early sea ice retreat matched the areas in which a shift in algal community composition was observed. Steel-Dwass's multiple comparison tests were used to assess the physical, chemical and biological parameters of the four clusters. We found a statistically significant difference in temperature between the haptophyte-dominated cluster and the other clusters, suggesting that the change in the phytoplankton communities was related to the earlier sea ice retreat in 2008 and the corollary increase in sea surface temperatures. Longer periods of open water during the summer, which are expected in the future, may affect food webs and biogeochemical cycles in the western Arctic due to shifts in phytoplankton community structure.

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