Model simulations of the M2and the K1tide in the Nordic Seas and the Arctic Ocean

The Arctic Ocean has been receiving&#160;more of the warm and saline Atlantic Water in the past&#160;decades. This water mass enters the Arctic Ocean via two Arctic gateways: the Barents Sea Opening and the Fram Strait.&#160;Here, we focus on the fractionation of Atlantic Water at these two gateways using a Lagrangian approach based on satellite-derived geostrophic velocities.&#160;Simulated particles are released at 70N at the inner and outer branch of the North Atlantic current system&#160;in the Nordic Seas. The trajectories toward the Fram Strait and Barents Sea Opening&#160;are found to be&#160;largely steered by the bottom topography and there is an indication of an&#160;anti-phase relationship in the number of particles reaching the gateways. There is, however, a significant&#160;cross-over of particles from the outer branch to the inner branch and into the Barents Sea, which is&#160;found to be related to high eddy kinetic energy between the branches. This cross-over may be important for Arctic climate variability.

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Improvement of the dose assessment tools on the basis of dispersion of the99Tc in the Nordic Seas and the Arctic Ocean

Radioprotection ◽

10.1051/radiopro/20095098 ◽

2009 ◽

Vol 44 (5) ◽

pp. 531-536 ◽

Cited By ~ 5

Author(s):

M. Iosjpe ◽

M. Karcher ◽

J. Gwynn ◽

I. Harms ◽

R. Gerdes ◽

...

Keyword(s):

Arctic Ocean ◽

Assessment Tools ◽

Dose Assessment ◽

The Arctic ◽

Nordic Seas ◽

The Arctic Ocean

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Freshwater pulses in the eastern Arctic Ocean during Saalian and Early Weichselian ice-sheet collapse

Quaternary Research ◽

10.1016/j.yqres.2003.07.008 ◽

2003 ◽

Vol 60 (3) ◽

pp. 243-251 ◽

Cited By ~ 26

Author(s):

Jochen Knies ◽

Christoph Vogt

Keyword(s):

Sea Ice ◽

Arctic Ocean ◽

Large Scale ◽

Barents Sea ◽

The Arctic ◽

Fram Strait ◽

Nordic Seas ◽

The Arctic Ocean ◽

Transpolar Drift ◽

Mis 5

AbstractImproved multiparameter records from the northern Barents Sea margin show two prominent freshwater pulses into the Arctic Ocean during MIS 5 that significantly disturbed the regional oceanic regime and probably affected global climate. Both pulses are associated with major iceberg-rafted debris (IRD) events, revealing intensive iceberg/sea ice melting. The older meltwater pulse occurred near the MIS 5/6 boundary (∼131,000 yr ago); its ∼2000 year duration and high IRD input accompanied by high illite content suggest a collapse of large-scale Saalian Glaciation in the Arctic Ocean. Movement of this meltwater with the Transpolar Drift current into the Fram Strait probably promoted freshening of Nordic Seas surface water, which may have increased sea-ice formation and significantly reduced deep-water formation. A second pulse of freshwater occurred within MIS 5a (∼77,000 yr ago); its high smectite content and relatively short duration is possibly consistent with sudden discharge of Early Weichselian ice-dammed lakes in northern Siberia as suggested by terrestrial glacial geologic data. The influence of this MIS 5a meltwater pulse has been observed at a number of sites along the Transpolar Drift, through Fram Strait, and into the Nordic Seas; it may well have been a trigger for the North Atlantic cooling event C20.

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A multi-model CMIP6 study of Arctic sea ice at 127 ka: Sea ice data compilation and model differences

10.5194/egusphere-egu2020-8628 ◽

2020 ◽

Author(s):

Louise Sime ◽

Masa Kageyama ◽

Marie Sicard ◽

Maria-Vittoria Guarino ◽

Anne de Vernal ◽

...

Keyword(s):

Sea Ice ◽

Arctic Ocean ◽

Arctic Sea Ice ◽

The Arctic ◽

Climate Modelling ◽

Last Interglacial ◽

Nordic Seas ◽

Arctic Sea ◽

The Arctic Ocean ◽

Intercomparison Project

The Last interglacial (LIG) is a period with increased summer insolation at high northern latitudes, which results in strong changes in the terrestrial and marine cryosphere. Understanding the mechanisms for this response via climate modelling and comparing the models&#8217; representation of climate reconstructions is one of the objectives set up by the Paleoclimate Modelling Intercomparison Project for its contribution to the sixth phase of the Coupled Model Intercomparison Project. Here we analyse the results from 12 climate models in terms of Arctic sea ice. The mean pre-industrial to LIG reduction in minimum sea ice area (SIA) reaches 59% (multi-model mean LIG area is 2.21 mill. km2, compared to 5.85 mill. km2 for the PI), and the range of model results for LIG minimum sea ice area (from 0.02 to 5.65 mill. km2) is larger than for PI (from 4.10 to 8.30 mill. km2). On the other hand there is little change for the maximum sea ice area (which is 12 mill. km2 for both the PI and the LIG, with a standard deviation of 1.04 mill. km2 for PI and 1.21 mill. km2 for LIG). To evaluate the model results we synthesize LIG sea ice data from marine cores collected in the Arctic Ocean, Nordic Seas and northern North Atlantic. South of 78oN, in the Atlantic and Nordic seas, the LIG was seasonally ice-free. North of 78oN there are some discrepancies between sea ice reconstructions based on dinocysts/foraminifers/ostracods and IP25: some sites have both seasonal and perennial interpretations based on the same core, but different indicators. Because of the con&#64258;icting interpretations it is not possible for any one model to match every data point in our data synthesis, or say whether the Arctic was seasonally ice-free. Drivers for the inter-model differences are: different phasing of the up and down short-wave anomalies over the Arctic ocean, associated with differences in model albedo; possible cloud property differences, in terms of optical depth; LIG ocean circulation changes which occur for some, but not all, LIG simulations. Finally we note that inter-comparisons between the LIG simulations, and simulations with moderate CO2 increase (during the transition to high CO2 levels), may yield insight into likely 21C Arctic sea ice changes using these LIG simulations.

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