The mechanism of 60-year and 15-year Arctic climate oscillations in climate model INM-CM5-0

Mapping Intimacies ◽

10.5194/egusphere-egu2020-7265 ◽

2020 ◽

Author(s):

Evgeny Volodin

Keyword(s):

Arctic Ocean ◽

North Atlantic ◽

Climate Model ◽

Atlantic Water ◽

Arctic Climate ◽

Time Interval ◽

Potential Predictability ◽

Arctic Warming ◽

Climate Oscillations ◽

Wind Currents

Natural variability of Arctic climate is studied on the basis of preindustrial run with climate model INM-CM5-0. &#160;The length of run is 1200 years. Temperature in Arctic shows significant peaks at periods of 60 and 15 years. Model climate oscillations are studied using technique of calculation of energy generation and impact to phase change.60-year oscillation is generated mainly by advection of Atlantic water to Arctic ocean. Anomaly of oceanic currents associated with the oscillation are generated by gradients of density. Before warm phase there is negative anomaly of density near coasts and continental slope. This leads to enhancing of Atlantic water inflow to Arctic ocean, warming, increasing of density near slope and turning to negative phase of oscillation. Cyclonic vorticity over warm Bartents and Kara seas leads to wind currents that enhance inflow of Atlantic water to Arctic.15-year oscillation is also generated by advection of Atlantic water to Arctic ocean, but anomalies of currents are generated mainly by wind stress. Before warm Arctic we have cold and fresh North Atlantic, that leads to positive NAO, it induces wind currents that transport more Atlantic water to Arctic ocean. This leads to Arctic warming, decrease of NAO and turn to opposite phase of oscillation. Warming of North Atlantic happens 3-4 years after maximum of Arctic warming. The response of Atlantic meridional streamfunction to the oscillation is studied."Ideal model" potential predictability experiments started from synthetic state preceding warm Arctic (cold and fresh North Atlantic) show that this oscillation can be predicted for time interval up to 10 years.

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The nature of 60-year oscillations of the Arctic climate according to the data of the INM RAS climate model

Russian Journal of Numerical Analysis and Mathematical Modelling ◽

10.1515/rnam-2018-0031 ◽

2018 ◽

Vol 33 (6) ◽

pp. 359-366 ◽

Cited By ~ 1

Author(s):

Evgenii M. Volodin

Keyword(s):

Arctic Ocean ◽

Climate Model ◽

Atlantic Water ◽

Arctic Climate ◽

The Arctic ◽

Natural Oscillations ◽

Oscillation Phase ◽

Arctic Warming ◽

Industrial Experiment ◽

The Arctic Ocean

Abstract Using the data of pre-industrial experiment with the INM-CM5 climate model for the period of 1200 years, we study the mechanism of natural oscillations of Arctic climate with the period of about 60 years. It is shown that for a quarter of the period prior to the Arctic warming there is a flow of Atlantic water into the Arctic ocean (AO) being more intense than usual, the salinity and density are less than usual near the coast and shelf border. As the result of advection of Atlantic water after Arctic warming, the water near the coast and shelf border becomes more salty and heavy, which leads to a weakening of the flow of Atlantic water and the change of oscillation phase. The conclusions are confirmed by calculations of the generation of anomalies of temperature, salinity, and velocity of currents by different terms, as well as estimation of the contribution of various components to the change of oscillation phase.

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Scenario Changes of Atlantic Water in the Arctic Ocean

Journal of Climate ◽

10.1175/jcli-d-14-00522.1 ◽

2015 ◽

Vol 28 (14) ◽

pp. 5523-5548 ◽

Cited By ~ 5

Author(s):

Zhenxia Long ◽

Will Perrie

Keyword(s):

Climate Change ◽

Arctic Ocean ◽

Heat Loss ◽

Climate Change Scenario ◽

Climate Model ◽

Atlantic Water ◽

Heat Fluxes ◽

Change Scenario ◽

Pressure System ◽

Central Arctic Ocean

Abstract The authors explore possible temperature modifications of the Atlantic Water Layer (AWL) induced by climate change, performing simulations for 1970 to 2099 with a coupled ice–ocean Arctic model (CIOM). Surface fields to drive the CIOM were provided by the Canadian Regional Climate Model (CRCM), driven by outputs from the Canadian Centre for Climate Modelling and Analysis (CCCma) Coupled Global Climate Model, version 3 (CGCM3) following the A1B climate change scenario. In the present climate, represented as 1990–2009, the CIOM can reliably reproduce the AWL compared to Polar Science Center Hydrographic Climatology (PHC) data. For the future climate, assuming the A1B climate change scenario, there is a significant increase in water volume transport into the central Arctic Ocean through Fram Strait due to the weakened atmospheric high pressure system over the western Arctic and an intensified atmospheric low pressure system over the Nordic seas. The AWL temperature tends to decrease from 0.36°C in the 2010s to 0.26°C in the 2060s. In the vertical, the warm Atlantic water core slightly expands before the 2030s, significantly shrinks after the 2050s, and essentially disappears by 2070–99, in the southern Beaufort Sea. The temperature decrease after 2030 is mainly due to the reduced heat fluxes in the Kara and Barents Seas. In the northeastern Barents and Kara Seas, the loss of sea ice increases the heat loss from the Atlantic water and reduces the water temperature near the bottom, contributing to decreased heat fluxes into the central Arctic Ocean, as well as decreased AWL temperature at central Arctic Ocean intermediate layers. In addition, the vertically integrated heat loss also plays an important role in the AWL cooling process.

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Simulated Arctic Ocean Freshwater Budgets in the Twentieth and Twenty-First Centuries

Journal of Climate ◽

10.1175/jcli3967.1 ◽

2006 ◽

Vol 19 (23) ◽

pp. 6221-6242 ◽

Cited By ~ 56

Author(s):

Marika M. Holland ◽

Joel Finnis ◽

Mark C. Serreze

Keyword(s):

Arctic Ocean ◽

North Atlantic ◽

Climate Model ◽

The Arctic ◽

Fram Strait ◽

Climate System Model ◽

Ice Melt ◽

East Greenland Current ◽

Freshwater Fluxes ◽

Gin Seas

Abstract The Arctic Ocean freshwater budgets in climate model integrations of the twentieth and twenty-first century are examined. An ensemble of six members of the Community Climate System Model version 3 (CCSM3) is used for the analysis, allowing the anthropogenically forced trends over the integration length to be assessed. Mechanisms driving trends in the budgets are diagnosed, and the implications of changes in the Arctic–North Atlantic exchange on the Labrador Sea and Greenland–Iceland–Norwegian (GIN) Seas properties are discussed. Over the twentieth and the twenty-first centuries, the Arctic freshens as a result of increased river runoff, net precipitation, and decreased ice growth. For many of the budget terms, the maximum 50-yr trends in the time series occur from approximately 1975 to 2025, suggesting that we are currently in the midst of large Arctic change. The total freshwater exchange between the Arctic and North Atlantic increases over the twentieth and twenty-first centuries with decreases in ice export more than compensated for by an increase in the liquid freshwater export. Changes in both the liquid and solid (ice) Fram Strait freshwater fluxes are transported southward by the East Greenland Current and partially removed from the GIN Seas. Nevertheless, reductions in GIN sea ice melt do result from the reduced Fram Strait transport and account for the largest term in the changing ocean surface freshwater fluxes in this region. This counteracts the increased ocean stability due to the warming climate and helps to maintain GIN sea deep-water formation.

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Significant variability of structure and predictability of Arctic Ocean surface pathways affects basin-wide connectivity

Communications Earth & Environment ◽

10.1038/s43247-021-00237-0 ◽

2021 ◽

Vol 2 (1) ◽

Author(s):

Chris Wilson ◽

Yevgeny Aksenov ◽

Stefanie Rynders ◽

Stephen J. Kelly ◽

Thomas Krumpen ◽

...

Keyword(s):

Arctic Ocean ◽

Velocity Structure ◽

Climate Model ◽

Global Climate ◽

Ocean Model ◽

The Arctic ◽

Fine Scale ◽

Potential Predictability ◽

Sources And Sinks ◽

Transpolar Drift

AbstractThe Arctic Ocean is of central importance for the global climate and ecosystem. It is a region undergoing rapid climate change, with a dramatic decrease in sea ice cover over recent decades. Surface advective pathways connect the transport of nutrients, freshwater, carbon and contaminants with their sources and sinks. Pathways of drifting material are deformed under velocity strain, due to atmosphere-ocean-ice coupling. Deformation is largest at fine space- and time-scales and is associated with a loss of potential predictability, analogous to weather often becoming unpredictable as synoptic-scale eddies interact and deform. However, neither satellite observations nor climate model projections resolve fine-scale ocean velocity structure. Here, we use a high-resolution ocean model hindcast and coarser satellite-derived ice velocities, to show: that ensemble-mean pathways within the Transpolar Drift during 2004–14 have large interannual variability and that both saddle-like flow structures and the presence of fine-scale velocity gradients are important for basin-wide connectivity and crossing time, pathway bifurcation, predictability and dispersion.

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Coupled evolution of tectonic, ocean circulations, and depositional regime in the southeastern Amundsen Basin

10.5194/egusphere-egu21-5190 ◽

2021 ◽

Author(s):

Estella Weigelt ◽

Christoph Gaedicke ◽

Wilfried Jokat

Keyword(s):

Arctic Ocean ◽

Ocean Circulation ◽

North Atlantic ◽

Middle Eocene ◽

The Arctic ◽

Circulation System ◽

Time Interval ◽

Fram Strait ◽

Acoustic Basement ◽

The Arctic Ocean

The Lomonosov Ridge (LR) and Fram Strait (FR) represent prominent morphologic features in the Arctic Ocean. Their tectonic evolution control ocean circulation, sedimentation environment, glacial processes and ecosystem through time. We present findings of a 300 km long seismic transect from the Gakkel Deep through the southeastern Amundsen Basin (AB), and onto the LR. The data image an up to 3 km thick sedimentary sequence that can be subdivided into six major seismic units.The two lower units AB-1 and AB-2 consist of syn-rift sediments of Paleocene to early Eocene age likely eroded off the Barents-Kara and Laptev Sea shelves, and the subsiding LR.AB-2 includes the time interval of the &#8220;Azolla event,&#8221; which is regarded as an era of a warm Arctic Ocean punctuated by episodic incursions of fresh water. The connection to North Atlantic waters via the Fram Strait was not yet established, and anoxic conditions prevailed in the young, still isolated Eurasian Basin. Also, the LR still was above or close to sea level and posed an obstacle for water exchange between the Eurasian and Amerasian basins.The top of AB-2 onlaps the acoustic basement at magnetic anomaly C21o (&#8764;47.3 Ma). Its contact with unit AB-3 above is marked by a striking loss in reflection amplitudes. This prominent interface can be traced through the AB, indicating widespread changes in tectonic and deposition conditions in the Arctic Ocean since the middle Eocene. For younger crust the depth of acoustic basement rises significantly, as well as the deformation of the surface. Both are probably linked to a reorganization of tectonic plates accompanied by a significant decrease in spreading rates.Units AB-3 and AB-4 indicate the accumulation of sediments between the middle Eocene and the earliest Miocene. Erosional, channel-like interruptions indicate these layers to reflect the stage when Fram Strait opened and continuously deepened. Incursions of water masses from the North Atlantic probably led to first bottom currents and produced erosion, slumping, and subsequent mixing of deposits.The upper units AB-5 to AB-6 show reflection characteristics and thicknesses similar all over the Arctic Ocean indicating that basin-wide pelagic sedimentation prevailed at least since late Oligocene. Drift bodies, sediment waves, and erosional structures indicate the onset of a modern ocean circulation system and bottom current activity in the early Miocene in the Amundsen Basin. At that time, the FR was developed widely, and also the LR no longer posed an obstacle between the Amerasia and Eurasia Basins. Lastly, unit AB-6 indicates pronounced variations in the sedimentary layers, and is associated with the onset of glacio-marine deposition since the Pliocene (5.3 Ma).

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Greenland Ice Sheet late-season melt: investigating multiscale drivers of K-transect events

The Cryosphere ◽

10.5194/tc-13-2241-2019 ◽

2019 ◽

Vol 13 (8) ◽

pp. 2241-2257 ◽

Cited By ~ 4

Author(s):

Thomas J. Ballinger ◽

Thomas L. Mote ◽

Kyle Mattingly ◽

Angela C. Bliss ◽

Edward Hanna ◽

...

Keyword(s):

Sea Ice ◽

North Atlantic ◽

Climate Model ◽

Ice Sheet ◽

Greenland Ice Sheet ◽

Open Water ◽

Atlantic Water ◽

Atmospheric Conditions ◽

Baffin Bay ◽

Late Season

Abstract. One consequence of recent Arctic warming is an increased occurrence and longer seasonality of above-freezing air temperature episodes. There is significant disagreement in the literature concerning potential physical connectivity between high-latitude open water duration proximate to the Greenland Ice Sheet (GrIS) and late-season (i.e., end-of-summer and autumn) GrIS melt events. Here, a new date of sea ice advance (DOA) product is used to determine the occurrence of Baffin Bay sea ice growth along Greenland's west coast for the 2011–2015 period. Over the 2-month period preceding the DOA, northwest Atlantic Ocean and atmospheric conditions are analyzed and linked to late-season melt events observed at a series of on-ice automatic weather stations (AWSs) along the K-transect in southwestern Greenland. Surrounding ice sheet, tundra, and coastal winds from the Modèle Atmosphérique Régional (MAR) and Regional Atmospheric Climate Model (RACMO) provide high-resolution spatial context to AWS observations and are analyzed along with ERA-Interim reanalysis fields to understand the meso-to-synoptic-scale (thermo)dynamic drivers of the melt events. Results suggest that late-season melt events, which primarily occur in the ablation area, are strongly affected by ridging atmospheric circulation patterns that transport warm, moist air from the subpolar North Atlantic toward west Greenland. Increasing concentrations of North Atlantic water vapor are shown to be necessary to produce melt conditions as autumn progresses. While thermal conduction and advection off south Baffin Bay open waters impact coastal air temperatures, local marine air incursions are obstructed by barrier flows and persistent katabatic winds along the western GrIS margin.

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