A dynamic and thermodynamic coupling view of the linkages between Eurasian cooling and Arctic warming

AbstractInvestigating the contrast between wintertime warming in the Arctic and cooling in Eurasia is of great importance for understanding regional climate change. In this study, we propose a dynamic and thermodynamic coupling view of the linkages between wintertime Arctic warming and Eurasian cooling since 1979. The key factors are the energy budget at the Earth’s surface, the diabatic heating and baroclinicity of the atmosphere, and subsurface ocean heat. A summertime origin of wintertime Arctic warming suggests a partial driving role of the Arctic in wintertime Eurasian cooling. The reasons for this finding are as follows. First, there is a dipole pattern in the diabatic heating change in winter over the Arctic Ocean corresponding to the anticyclonic circulation that links Eurasian cooling and Arctic warming. Second, the change in diabatic heating of the atmosphere is determined by sensible heat at the Earth’s surface through vertical diffusion. Third, the positive sensible heat change in the eastern Arctic sector in winter originates from the summertime enhanced absorption of solar radiation by the subsurface ocean over the sea ice loss region. Meanwhile, the negative sensible heat change in the western Arctic sector and wide Arctic warming can be explained by the circulation development triggered by the change in the east. Additionally, the background strong baroclinicity of the atmosphere in mid-high latitudes and corresponding two-way Arctic and mid-latitude interactions are necessary for circulation development in winter. Furthermore, the seasonality of the changes indicates that Eurasian cooling occurs only in winter because the diabatic heating change in the Arctic is strongest in winter. Overall, the comprehensive mechanisms from the summertime Earth’s surface and subsurface ocean to the wintertime atmosphere suggest a driving role of the Arctic. Note that the situation in interannual variability is more complex than the overall trend because the persistence of the influence of summertime sea ice is weakly established in terms of interannual variability.

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Quantifying the role of ocean coupling in Arctic amplification and sea-ice loss over the 21st century

npj Climate and Atmospheric Science ◽

10.1038/s41612-021-00204-8 ◽

2021 ◽

Vol 4 (1) ◽

Author(s):

Rei Chemke ◽

Lorenzo M. Polvani ◽

Jennifer E. Kay ◽

Clara Orbe

Keyword(s):

Sea Ice ◽

The Arctic ◽

Climate Projections ◽

Arctic Amplification ◽

Ocean Coupling ◽

Quantitative Understanding ◽

Climatic Impacts ◽

Dynamic Components ◽

Thermodynamic Coupling

AbstractThe enhanced warming of the Arctic, relative to other parts of the Earth, a phenomenon known as Arctic amplification, is one of the most striking features of climate change, and has important climatic impacts for the entire Northern Hemisphere. Several mechanisms are believed to be responsible for Arctic amplification; however, a quantitative understanding of their relative importance is still missing. Here, using ensembles of model integrations, we quantify the contribution of ocean coupling, both its thermodynamic and dynamic components, to Arctic amplification over the 20th and 21st centuries. We show that ocean coupling accounts for ~80% of the amplification by 2100. In particular, we show that thermodynamic coupling is responsible for future amplification and sea-ice loss as it overcomes the effect of dynamic coupling which reduces the amplification and sea-ice loss by ~35%. Our results demonstrate the utility of targeted numerical experiments to quantify the role of specific mechanisms in Arctic amplification, for better constraining climate projections.

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Contributors to linkage between Arctic warming and East Asian winter climate

Climate Dynamics ◽

10.1007/s00382-021-05820-x ◽

2021 ◽

Author(s):

Xinping Xu ◽

Shengping He ◽

Yongqi Gao ◽

Botao Zhou ◽

Huijun Wang

Keyword(s):

Sea Ice ◽

General Circulation ◽

Initial Conditions ◽

Wave Train ◽

East Asian ◽

Surface Air Temperature ◽

General Circulation Models ◽

The Arctic ◽

Winter Climate ◽

Arctic Warming

AbstractPrevious modelling and observational studies have shown discrepancies in the interannual relationship of winter surface air temperature (SAT) between Arctic and East Asia, stimulating the debate about whether Arctic change can influence midlatitude climate. This study uses two sets of coordinated experiments (EXP1 and EXP2) from six different atmospheric general circulation models. Both EXP1 and EXP2 consist of 130 ensemble members, each of which in EXP1 (EXP2) was forced by the same observed daily varying sea ice and daily varying (daily climatological) sea surface temperature (SST) for 1982–2014 but with different atmospheric initial conditions. Large spread exists among ensemble members in simulating the Arctic–East Asian SAT relationship. Only a fraction of ensemble members can reproduce the observed deep Arctic warming–cold continent pattern which extends from surface to upper troposphere, implying the important role of atmospheric internal variability. The mechanisms of deep Arctic warming and shallow Arctic warming are further distinguished. Arctic warming aloft is caused primarily by poleward moisture transport, which in conjunction with the surface warming coupled with sea ice melting constitutes the surface-amplified deep Arctic warming throughout the troposphere. These processes associated with the deep Arctic warming may be related to the forcing of remote SST when there is favorable atmospheric circulation such as Rossby wave train propagating from the North Atlantic into the Arctic.

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Importance of Human-Induced Nitrogen Flux Increases for Simulated Arctic Warming

Journal of Climate ◽

10.1175/jcli-d-20-0180.1 ◽

2021 ◽

Vol 34 (10) ◽

pp. 3799-3819

Author(s):

Hyung-Gyu Lim ◽

Jong-Yeon Park ◽

John P. Dunne ◽

Charles A. Stock ◽

Sung-Ho Kang ◽

...

Keyword(s):

Sea Ice ◽

Arctic Ocean ◽

The Arctic ◽

Biogeochemical Model ◽

Biological Feedback ◽

Arctic Warming ◽

The Arctic Ocean ◽

N Fluxes ◽

The Impact ◽

Chlorophyll Concentrations

AbstractHuman activities such as fossil fuel combustion, land-use change, nitrogen (N) fertilizer use, emission of livestock, and waste excretion accelerate the transformation of reactive N and its impact on the marine environment. This study elucidates that anthropogenic N fluxes (ANFs) from atmospheric and river deposition exacerbate Arctic warming and sea ice loss via physical–biological feedback. The impact of physical–biological feedback is quantified through a suite of experiments using a coupled climate–ocean–biogeochemical model (GFDL-CM2.1-TOPAZ) by prescribing the preindustrial and contemporary amounts of riverine and atmospheric N fluxes into the Arctic Ocean. The experiment forced by ANFs represents the increase in ocean N inventory and chlorophyll concentrations in present and projected future Arctic Ocean relative to the experiment forced by preindustrial N flux inputs. The enhanced chlorophyll concentrations by ANFs reinforce shortwave attenuation in the upper ocean, generating additional warming in the Arctic Ocean. The strongest responses are simulated in the Eurasian shelf seas (Kara, Barents, and Laptev Seas; 65°–90°N, 20°–160°E) due to increased N fluxes, where the annual mean surface temperature increase by 12% and the annual mean sea ice concentration decrease by 17% relative to the future projection, forced by preindustrial N inputs.

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On the effect of rheology on seasonal sea-ice simulations

Annals of Glaciology ◽

10.3189/1991aog15-1-17-25 ◽

1991 ◽

Vol 15 ◽

pp. 17-25 ◽

Cited By ~ 6

Author(s):

Chi F. Ip ◽

William D. Hibler ◽

Gregory M. Flato

Keyword(s):

Shear Stress ◽

Sea Ice ◽

Correlation Coefficients ◽

Arctic Basin ◽

The Arctic ◽

Flow Rule ◽

Average Model ◽

Ice Drift ◽

Cavitating Fluid

A generalized numerical model which allows for a variety of non-linear rheologies is developed for the seasonal simulation of sea-ice circulation and thickness. The model is used to investigate the effects (such as the role of shear stress and the existence of a flow rule) of different rheologies on the ice-drift pattern and build-up in the Arctic Basin. Differences in local drift seem to be closely related to the amount of allowable shear stress. Similarities are found between the elliptical and square cases and between the Mohr-Coulomb and cavitating fluid cases. Comparisons between observed and simulated buoy drift are made for several buoy tracks in the Arctic Basin. Correlation coefficients to the observed buoy drift range from 0.83 for the cavitating fluid to 0.86 for the square rheology. The average ratio of buoy-drift distance to average model-drift distance for several buoys is 1.15 (square), 1.18 (elliptical), 1.30 (Mohr-Coulomb) and 1.40 (cavitating fluid).

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Influence of Nordic Seas dynamics on the Atlantic Water propagation and its impacts on sea ice concentration.

10.5194/egusphere-egu21-14798 ◽

2021 ◽

Author(s):

Sourav Chatterjee ◽

Roshin P Raj ◽

Laurent Bertino ◽

Nuncio Murukesh

Keyword(s):

Sea Ice ◽

Deep Water ◽

Atlantic Water ◽

The Arctic ◽

Deep Water Formation ◽

Sea Ice Concentration ◽

Nordic Seas ◽

Ice Concentration ◽

Water Formation

<p>Enhanced intrusion of warm and saline Atlantic Water (AW) to the Arctic Ocean (AO) in recent years has drawn wide interest of the scientific community owing to its potential role in &#8216;Arctic Amplification&#8217;. Not only the AW has warmed over the last few decades , but its transfer efficiency have also undergone significant modifications due to changes in atmosphere and ocean dynamics at regional to large scales. The Nordic Seas (NS), in this regard, play a vital role as the major exchange of polar and sub-polar waters takes place in this region. Further, the AW and its significant modification on its way to AO via the Nordic Seas has large scale implications on e.g., deep water formation, air-sea heat fluxes. Previous studies have suggested that a change in the sub-polar gyre dynamics in the North Atlantic controls the AW anomalies that enter the NS and eventually end up in the AO. However, the role of NS dynamics in resulting in the modifications of these AW anomalies are not well studied. Here in this study, we show that the Nordic Seas are not only a passive conduit of AW anomalies but the ocean circulations in the Nordic Seas, particularly the Greenland Sea Gyre (GSG) circulation can significantly change the AW characteristics between the entry and exit point of AW in the NS. Further, it is shown that the change in GSG circulation can modify the AW heat distribution in the Nordic Seas and can potentially influence the sea ice concentration therein. Projected enhanced atmospheric forcing in the NS in a warming Arctic scenario and the warming trend of the AW can amplify the role of NS circulation in AW propagation and its impact on sea ice, freshwater budget and deep water formation.</p>

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2. The physical environment

10.1093/actrade/9780198819288.003.0002 ◽

2021 ◽

pp. 14-38

Author(s):

Klaus Dodds ◽

Jamie Woodward

Keyword(s):

Sea Ice ◽

Physical Environment ◽

Greenland Ice Sheet ◽

The Arctic ◽

Far North ◽

Sea Ice Decline ◽

Antarctic Continent ◽

Polar Opposite ◽

The Antarctic

‘The physical environment’ describes the Arctic as the polar opposite of the Antarctic continent as it is an ocean semi-enclosed by land. The rocks of the Arctic record key periods in Earth history. The Arctic environment has had an interesting path of evolution. Why is the Arctic cold today? The polar latitudes actually receive less solar energy than the rest of the Earth's surface. What is the key role of sea ice in the Arctic climate system? How does sea ice decline impact upon the Arctic Ocean? The Greenland ice sheet, high latitude glaciers, and the importance of permafrost in the far north are also important topics related to the physical environment.

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Eurasian Cooling Linked with Arctic Warming: Insights from PV Dynamics

Journal of Climate ◽

10.1175/jcli-d-19-0073.1 ◽

2020 ◽

Vol 33 (7) ◽

pp. 2627-2644

Author(s):

Yongkun Xie ◽

Guoxiong Wu ◽

Yimin Liu ◽

Jianping Huang

Keyword(s):

Vertical Structure ◽

Diabatic Heating ◽

Linear Trend ◽

Three Dimensional ◽

Lower Troposphere ◽

The Arctic ◽

Arctic Warming ◽

Circulation Change ◽

General Dynamics ◽

Upper Level

AbstractThe three-dimensional connections between Eurasian cooling and Arctic warming since 1979 were investigated using potential vorticity (PV) dynamics. We found that Eurasian cooling can be regulated by Arctic warming through PV adaptation and PV advection. Here, PV adaptation refers to the adaptation of PV to forcing and coherent dynamic–thermodynamic adaptation to PV change. In a PV perspective, first, the anticyclonic circulation change over the Arctic is produced by a negative PV change through PV adaptation, in which the change means the linear trend from 1979 to 2017. The negative PV change is directly regulated by Arctic warming because the vertical structure of Arctic warming is stronger at lower levels, which generates a negative PV change through the diabatic heating effect. Second, the circulation change produces a change in horizontal PV advection due to the existence of climatological PV gradients. Thus, as a balanced result, both the circulation change and PV change extend to the midlatitudes through horizontal PV advection and PV adaptation. Eventually, Eurasian cooling at the surface and in the lower troposphere is dominated by PV changes at the surface through PV adaptation. Meanwhile, enhanced Eurasian cooling in the middle troposphere is dominated by top-down influences of upper-level PV change through PV adaptation. Nevertheless, the upper-level PV changes are still contributed to by horizontal PV advection associated with Arctic warming. Overall, the general dynamics connecting Eurasian cooling with Arctic warming are demonstrated in a PV view.

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The role of cyclone activity in snow accumulation on Arctic sea ice

Nature Communications ◽

10.1038/s41467-019-13299-8 ◽

2019 ◽

Vol 10 (1) ◽

Cited By ~ 4

Author(s):

M. A. Webster ◽

C. Parker ◽

L. Boisvert ◽

R. Kwok

Keyword(s):

Sea Ice ◽

Snow Accumulation ◽

Arctic Sea Ice ◽

Surface Energy Budget ◽

The Arctic ◽

Cyclone Activity ◽

In Situ Data ◽

Arctic Sea ◽

Spatio Temporal

AbstractIdentifying the mechanisms controlling the timing and magnitude of snow accumulation on sea ice is crucial for understanding snow’s net effect on the surface energy budget and sea-ice mass balance. Here, we analyze the role of cyclone activity on the seasonal buildup of snow on Arctic sea ice using model, satellite, and in situ data over 1979–2016. On average, 44% of the variability in monthly snow accumulation was controlled by cyclone snowfall and 29% by sea-ice freeze-up. However, there were strong spatio-temporal differences. Cyclone snowfall comprised ~50% of total snowfall in the Pacific compared to 83% in the Atlantic. While cyclones are stronger in the Atlantic, Pacific snow accumulation is more sensitive to cyclone strength. These findings highlight the heterogeneity in atmosphere-snow-ice interactions across the Arctic, and emphasize the need to scrutinize mechanisms governing cyclone activity to better understand their effects on the Arctic snow-ice system with anthropogenic warming.

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Role of Ural blocking in Arctic sea ice loss and its connection with Arctic warming in winter

Climate Dynamics ◽

10.1007/s00382-020-05545-3 ◽

2020 ◽

Author(s):

Dong-Jae Cho ◽

Kwang-Yul Kim

Keyword(s):

Sea Ice ◽

Turbulent Flux ◽

Longwave Radiation ◽

Arctic Sea Ice ◽

Sea Surface ◽

Feedback Process ◽

Arctic Warming ◽

Open Sea

AbstractUral blocking (UB) is suggested as one of the contributors to winter sea ice loss in the Barents–Kara Seas (BKS). This study compares UB with Arctic warming (AW) in order to delineate the role of UB on winter sea ice loss and its potential link with AW. A detailed comparison reveals that UB and AW are partly linked on sub-seasonal scales via a two-way interaction; circulation produced by AW affects UB and advection induced by UB affects temperature in AW. On the other hand, the long-term impacts of AW and UB on the sea ice concentration in the BKS are distinct. In AW, strong turbulent flux from the sea surface warms the lower troposphere, increases downward longwave radiation, and broadens the open sea surface. This feedback process explains the substantial sea ice reduction observed in the BKS in association with long-term accelerating trend. Patterns of turbulent flux, net evaporation, and net longwave radiation at surface associated with UB are of opposite signs to those associated with AW, which implies that moisture and heat flux is suppressed as warm and moist air is advected from mid-latitudes. As a result, vertical feedback process is hindered under UB. The qualitative and quantitative differences arise in terms of their impacts on sea ice concentrations in the BKS, because strong turbulent flux from the open sea surface is a main driving force in AW whereas heat and moisture advection is a main forcing in UB.

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