The shallowing surface temperature inversions in the Arctic

2021 ◽  
pp. 1-30
Author(s):  
Lin Zhang ◽  
Minghu Ding ◽  
Tingfeng Dou ◽  
Yi Huang ◽  
Junmei Lv ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
21St Century ◽  
Barents Sea ◽  
Atmospheric Stability ◽  
Heat Fluxes ◽  
Spatiotemporal Variability ◽  
The Arctic ◽  
The Arctic Ocean ◽  
Temperature Inversions

AbstractTemperature inversion plays an important role in various physical processes by affecting the atmospheric stability, regulating the development of clouds and fog, and controlling the transport of heat and moisture fluxes. In the past few decades, previous studies have analyzed the spatiotemporal variability of Arctic inversions, but few studies have investigated changes in temperature inversions. In this study, the changes in the depth of Arctic inversions in the mid-21st century are projected based on a 30-member ensemble from the Community Earth System Model Large Ensemble (CESM-LE) project. The ERA-Interim, JRA-55, and NCEP-NCAR reanalyses were employed to verify the model results. The CESM-LE can adequately reproduce the spatial distribution and trends of present-day inversion depth in the Arctic, and the simulation is better in winter. The mean inversion depth in the CESM-LE is slightly underestimated, and the discrepancy is less than 11 hPa within a reasonable range. The model results show that during the mid-21st century, the inversion depth will strongly decrease in autumn and slightly decrease in winter. The shallowing of inversion is most obvious over the Arctic Ocean, and the maximum decrease is over 65 hPa in the Pacific sector in autumn. In contrast, the largest decrease in the inversion depth, which is more than 45 hPa, occurs over the Barents Sea in winter. Moreover, the area where the inversion shallows is consistent with the area where the sea ice is retreating, indicating that the inversion depth over the Arctic Ocean in autumn and winter is likely regulated by the sea ice extent through modulating surface heat fluxes.

Separating the influences of low-latitude warming and sea-ice loss on Northern Hemisphere climate change

2022 ◽  
pp. 1-59
Author(s):  
Paul J. Kushner ◽  
Russell Blackport ◽  
Kelly E. McCusker ◽  
Thomas Oudar ◽  
Lantao Sun ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Northern Hemisphere ◽  
North Atlantic ◽  
High Latitude ◽  
North Pacific ◽  
Heat Fluxes ◽  
The Arctic ◽  
Low Latitude ◽  
The Arctic Ocean

Abstract Analyzing a multi-model ensemble of coupled climate model simulations forced with Arctic sea-ice loss using a two-parameter pattern-scaling technique to remove the cross-coupling between low- and high-latitude responses, the sensitivity to high-latitude sea-ice loss is isolated and contrasted to the sensitivity to low-latitude warming. In spite of some differences in experimental design, the Northern Hemisphere near-surface atmospheric sensitivity to sea-ice loss is found to be robust across models in the cold season; however, a larger inter-model spread is found at the surface in boreal summer, and in the free tropospheric circulation. In contrast, the sensitivity to low-latitude warming is most robust in the free troposphere and in the warm season, with more inter-model spread in the surface ocean and surface heat flux over the Northern Hemisphere. The robust signals associated with sea-ice loss include upward turbulent and longwave heat fluxes where sea-ice is lost, warming and freshening of the Arctic ocean, warming of the eastern North Pacific relative to the western North Pacific with upward turbulent heat fluxes in the Kuroshio extension, and salinification of the shallow shelf seas of the Arctic Ocean alongside freshening in the subpolar North Atlantic. In contrast, the robust signals associated with low-latitude warming include intensified ocean warming and upward latent heat fluxes near the western boundary currents, freshening of the Pacific Ocean, salinification of the North Atlantic, and downward sensible and longwave fluxes over the ocean.

scholarly journals Effects of sea ice cover on satellite-detected primary production in the Arctic Ocean

2016 ◽  
Vol 12 (11) ◽  
pp. 20160223 ◽  
Author(s):  
Mati Kahru ◽  
Zhongping Lee ◽  
B. Greg Mitchell ◽  
Cynthia D. Nevison
Keyword(s):  
Sea Ice ◽  
Primary Production ◽  
Arctic Ocean ◽  
Barents Sea ◽  
Net Primary Production ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Primary Input ◽  
High Productivity ◽  
The Arctic Ocean

The influence of decreasing Arctic sea ice on net primary production (NPP) in the Arctic Ocean has been considered in multiple publications but is not well constrained owing to the potentially large errors in satellite algorithms. In particular, the Arctic Ocean is rich in coloured dissolved organic matter (CDOM) that interferes in the detection of chlorophyll a concentration of the standard algorithm, which is the primary input to NPP models. We used the quasi-analytic algorithm (Lee et al . 2002 Appl. Opti. 41 , 5755−5772. ( doi:10.1364/AO.41.005755 )) that separates absorption by phytoplankton from absorption by CDOM and detrital matter. We merged satellite data from multiple satellite sensors and created a 19 year time series (1997–2015) of NPP. During this period, both the estimated annual total and the summer monthly maximum pan-Arctic NPP increased by about 47%. Positive monthly anomalies in NPP are highly correlated with positive anomalies in open water area during the summer months. Following the earlier ice retreat, the start of the high-productivity season has become earlier, e.g. at a mean rate of −3.0 d yr −1 in the northern Barents Sea, and the length of the high-productivity period has increased from 15 days in 1998 to 62 days in 2015. While in some areas, the termination of the productive season has been extended, owing to delayed ice formation, the termination has also become earlier in other areas, likely owing to limited nutrients.

scholarly journals Mechanisms influencing seasonal-to-interannual prediction skill of sea ice extent in the Arctic Ocean in MIROC

2017 ◽  
Author(s):  
Jun Ono ◽  
Hiroaki Tatebe ◽  
Yoshiki Komuro ◽  
Masato I. Nodzu ◽  
Masayoshi Ishii
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Barents Sea ◽  
Heat Content ◽  
The Arctic ◽  
Subsurface Water ◽  
Lead Times ◽  
Sea Ice Concentration ◽  
Sea Ice Extent ◽  
The Arctic Ocean

Abstract. To assess the skill of predictions of the seasonal-to-interannual detrended sea ice extent in the Arctic Ocean (SIEAO) and to clarify the underlying physical processes, we conducted ensemble hindcasts, started on January 1st, April 1st, July 1st, and October 1st for each year from 1980 to 2011, for lead times of up three years, using the Model for Interdisciplinary Research on Climate (MIROC) version 5 initialized with the observed atmosphere and ocean anomalies and sea ice concentration. Significant skill is found for the winter months: the December SIEAO can be predicted up to 1 year ahead. This skill is attributed to the subsurface ocean heat content originating in the North Atlantic. The subsurface water flows into the Barents Sea from spring to fall and emerges at the surface in winter by vertical mixing, and eventually affects the sea ice variability there. Meanwhile, the September SIEAO predictions are skillful for lead times of up to 3 months, due to the persistence of sea ice in the Beaufort, Chukchi, and East Siberian Seas initialized in July, as suggested by previous studies.

scholarly journals Arctic sea ice anomalies during the MOSAiC winter 2019/20

2021 ◽  
Author(s):  
Klaus Dethloff ◽  
Wieslaw Maslowski ◽  
Stefan Hendricks ◽  
Younjoo Lee ◽  
Helge F. Goessling ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Barents Sea ◽  
Arctic Sea Ice ◽  
Heat Fluxes ◽  
The Arctic ◽  
Turbulent Heat ◽  
Central Arctic Ocean ◽  
Sea Ice Thickness ◽  
The Arctic Oscillation

Abstract. As the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) project went into effect during the winter of 2019/2020, the Arctic Oscillation (AO) has experienced some of the largest shifts from a highly negative index in November 2019 to an extremely positive index during January-February-March (JFM) 2020. Here we analyse the sea ice thickness (SIT) distribution based on CryoSat-2/SMOS satellite data augmented with results from the hindcast simulation by the fully coupled Regional Arctic System Model (RASM) for the time period from November 2019 through March 2020. A notable result of the positive AO phase during JFM 2020 were large SIT anomalies, up to 1.3 m, which emerged in the Barents-Sea (BS), along the northeastern Canadian coast and in parts of the central Arctic Ocean. These anomalies appear to be driven by nonlinear interactions between thermodynamic and dynamic processes. In particular, in the Barents- and Kara Seas (BKS) they are a result of an enhanced ice growth connected with the colder temperature anomalies and the consequence of intensified atmospheric-driven sea ice transport and deformations (i.e. divergence and shear) in this area. Low-pressure anomalies, which developed over the Eastern Arctic during JFM 2020, increased northerly winds from the cold Arctic Ocean to the BS and accelerated the southward drift of the MOSAiC ice floe. The satellite-derived and model-simulated sea ice velocity anomalies, which compared well during JFM 2020, indicate a strong acceleration of the Transpolar Drift relative to the mean for the past decade, with intensified speeds up to 6 km/day. As a consequence, sea ice transport and deformations driven by atmospheric wind forcing accounted for bulk of SIT anomalies, especially in January and February 2020. The unusual AO shift and the related sea ice anomalies during the MOSAiC winter 2019/20 are within the range of simulated states in the forecast ensemble. RASM intra-annual ensemble forecast simulations, forced with different atmospheric boundary conditions from November 1, 2019 through April 30, 2020, show a pronounced internally generated variability in the sea ice volume. A comparison of the respective SIT distribution and turbulent heat fluxes during the positive AO phase in JFM 2020 and the negative AO phase in JFM 2010 further corroborates the conclusion, that winter sea ice conditions of the Arctic Ocean can be significantly altered by AO variability.

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

2003 ◽  
Vol 60 (3) ◽  
pp. 243-251 ◽  
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.

Unprecedented decline of sea ice thickness in Fram Strait in 2017-2018

2021 ◽  
Author(s):  
Hiroshi Sumata ◽  
Laura de Steur ◽  
Dmitry Divine ◽  
Olga Pavlova ◽  
Sebastian Gerland
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Barents Sea ◽  
North Atlantic Ocean ◽  
The Arctic ◽  
Ice Thickness ◽  
Fram Strait ◽  
Sea Ice Thickness ◽  
Drift Speed ◽  
The Arctic Ocean

<p><span><span>Fram Strait is the major gateway connecting the Arctic Ocean and the northern North Atlantic Ocean where about 80 to 90% of sea ice outflow from the Arctic Ocean takes place. Long-term observations from the Fram Strait Arctic Outflow Observatory maintained by the Norwegian Polar Institute captured an unprecedented decline<!-- should we somehow add information that this statement is limited to the time since the early 1990s? --><!-- Reply to Sebastian Gerland (2021/01/12, 15:45): "..." I slightly modified the sentence to mention this. --> of sea ice thickness in 2017 – 2018 since comprehensive observations started in the early 1990s. Four Ice Profiling Sonars moored in the East Greenland Current in Fram Strait simultaneously recorded 50 – 70 cm decline of annual mean ice thickness in comparison with preceding years. A backward trajectory analysis revealed that the decline was attributed to an anomalous sea level pressure pattern from 2017 autumn to 2018 summer. Southerly wind associated with a dipole pressure anomaly between Greenland and the Barents Sea prevented southward motion of ice floes north of Fram Strait. Hence ice pack was exposed to warm Atlantic Water in the north of Fram Strait 2 – 3 times longer than the average year, allowing more melt <!-- should also slower freezing or reduced freezing rates mentioned here during winter and spring (in addition to melt in summer and autumn)? --><!-- Reply to Sebastian Gerland (2021/01/12, 15:46): "..." I would like to keep this sentence as it is, since the analysis implies sea ice melt occurred in the vicinity of Fram Strait in winter (probably due to ocean heat flux), though we don’t have direct measurements of 2018 event. This could be an interesting implications of this study, and seeds for further investigation. -->to happen. At the same time, the dipole anomaly was responsible for the slowest observed annual mean ice drift speed in Fram Strait in the last two decades. As a consequence of the record minimum of ice thickness and the slowest drift speed, the sea ice volume transport through the Fram Strait dropped by more than 50% in comparison with the 2010 – 2017 average.</span></span></p>

Atmospheric and oceanic drivers of regional Arctic winter sea-ice variability in present and future climates

2021 ◽  
Author(s):  
Jakob Dörr ◽  
Marius Årthun ◽  
Tor Eldevik ◽  
Erica Madonna
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Heat Transport ◽  
Barents Sea ◽  
Arctic Sea Ice ◽  
The Arctic ◽  
Ocean Heat Transport ◽  
The Pacific ◽  
Arctic Sea ◽  
The Arctic Ocean

<p>The recent retreat of Arctic sea ice area is overlaid by strong internal variability on all timescales. In winter, sea ice retreat and variability are currently dominated by the Barents Sea, primarily driven by variable ocean heat transport from the Atlantic. Climate models from the latest intercomparison project CMIP6 project that the future loss of winter Arctic sea ice spreads throughout the Arctic Ocean and, hence, that other regions of the Arctic Ocean will see increased sea-ice variability. It is, however, not known how the influence of ocean heat transport will change, and to what extent and in which regions other drivers, such as atmospheric circulation or river runoff into the Arctic Ocean, will become important. Using a combination of observations and simulations from the Community Earth System Model Large Ensemble (CESM-LE), we analyze and contrast the present and future regional drivers of the variability of the winter Arctic sea ice cover. We find that for the recent past, both observations and CESM-LE show that sea ice variability in the Atlantic and Pacific sector of the Arctic Ocean is influenced by ocean heat transport through the Barents Sea and Bering Strait, respectively. The two dominant modes of large-scale atmospheric variability – the Arctic Oscillation and the Pacific North American pattern – are only weakly related to recent regional sea ice variability. However, atmospheric circulation anomalies associated with regional sea ice variability show distinct patterns for the Atlantic and Pacific sectors consistent with heat and humidity transport from lower latitudes. In the future, under a high emission scenario, CESM-LE projects a gradual expansion of the footprint of the Pacific and Atlantic inflows, covering the whole Arctic Ocean by 2050-2079. This study highlights the combined importance of future Atlantification and Pacification of the Arctic Ocean and improves our understanding of internal climate variability which essential in order to predict future sea ice changes under anthropogenic warming.   </p><p> </p>

Transformation of Atlantic Water in the Barents Sea in winter: overview of “Transarctika-2019” cruise results

2020 ◽  
Author(s):  
Vladimir Ivanov ◽  
Ivan Frolov ◽  
Kirill Filchuk
Keyword(s):  
Characteristic Feature ◽  
Sea Ice ◽  
Arctic Ocean ◽  
Water Column ◽  
Barents Sea ◽  
Atlantic Water ◽  
The Arctic ◽  
The Barents Sea ◽  
Open Sea ◽  
The Arctic Ocean

<p>In the recent few years the topic of accelerated sea ice loss, and related changes in the vertical structure of water masses in the East-Atlantic sector of the Arctic Ocean, including the Barents Sea and the western part of the Nansen Basin, has been in the foci of multiple studies. This region even earned the name the “Arctic warming hotspot”, due to the extreme retreat of sea ice and clear signs of change in the vertical hydrographic structure from the Arctic type to the sub-Arctic one. A gradual increase in temperature and salinity in this area has been observed since the mid-2000s. This trend is hypothetically associated with a general decrease in the volume of sea ice in the Arctic Ocean, which leads to a decrease of ice import in the Barents Sea, salinization, weakening of density stratification, intensification of vertical mixing and an increase of heat and salt fluxes from the deep to the upper mixed layer. The result of such changes is a further reduction of sea ice, i.e. implementation of positive feedback, which is conventionally refereed as the “atlantification. Due to the fact that the Barents Sea is a relatively shallow basin, the process of atlantification might develop here much faster than in the deep Nansen Basin. Thus, theoretically, the hydrographic regime in the northern part of the Barents Sea may rapidly transform to a “Nordic Seas – wise”, a characteristic feature of which is the year-round absence of the ice cover with debatable consequences for the climate and ecosystem of the region and adjacent land areas. Due to the obvious reasons, historical observations in the Barents Sea mostly cover the summer season. Here we present a rare oceanographic data, collected during the late winter - early spring in 2019. Measurements were occupied at four sequential oceanographic surveys from the boundary between the Norwegian Sea and the Barents Sea – the so called Barents Sea opening to the boundary between the Barents Sea and the Kara Sea. Completed hydrological sections allowed us to estimate the contribution of the winter processes in the Atlantic Water transformation at the end of the winter season. Characteristic feature of the observed transformation is the homogenization of the near-to-bottom part of the water column with remaining stratification in the upper part. A probable explanation of such changes is the dominance of shelf convection and cascading of dense water over the open sea convection. In this case, complete homogenization of the water column does not occur, since convection in the open sea is impeded by salinity and density stratification, which is maintained by melting of the imported sea ice in the relatively warm water. The study was supported by RFBR grant # 18-05-60083.</p>

scholarly journals The Arctic Ocean Seasonal Cycles of Heat and Freshwater Fluxes: Observation-Based Inverse Estimates

2018 ◽  
Vol 48 (9) ◽  
pp. 2029-2055 ◽  
Author(s):  
Takamasa Tsubouchi ◽  
Sheldon Bacon ◽  
Yevgeny Aksenov ◽  
Alberto C. Naveira Garabato ◽  
Agnieszka Beszczynska-Möller ◽  
...  
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Barents Sea ◽  
Numerical Models ◽  
Water Layer ◽  
Atlantic Water ◽  
Surface Fluxes ◽  
The Arctic ◽  
Bering Strait ◽  
The Arctic Ocean

AbstractThis paper presents the first estimate of the seasonal cycle of ocean and sea ice heat and freshwater (FW) fluxes around the Arctic Ocean boundary. The ocean transports are estimated primarily using 138 moored instruments deployed in September 2005–August 2006 across the four main Arctic gateways: Davis, Fram, and Bering Straits, and the Barents Sea Opening (BSO). Sea ice transports are estimated from a sea ice assimilation product. Monthly velocity fields are calculated with a box inverse model that enforces mass and salt conservation. The volume transports in the four gateways in the period (annual mean ± 1 standard deviation) are −2.1 ± 0.7 Sv in Davis Strait, −1.1 ± 1.2 Sv in Fram Strait, 2.3 ± 1.2 Sv in the BSO, and 0.7 ± 0.7 Sv in Bering Strait (1 Sv ≡ 106 m3 s−1). The resulting ocean and sea ice heat and FW fluxes are 175 ± 48 TW and 204 ± 85 mSv, respectively. These boundary fluxes accurately represent the annual means of the relevant surface fluxes. The ocean heat transport variability derives from velocity variability in the Atlantic Water layer and temperature variability in the upper part of the water column. The ocean FW transport variability is dominated by Bering Strait velocity variability. The net water mass transformation in the Arctic entails a freshening and cooling of inflowing waters by 0.62 ± 0.23 in salinity and 3.74° ± 0.76°C in temperature, respectively, and a reduction in density by 0.23 ± 0.20 kg m−3. The boundary heat and FW fluxes provide a benchmark dataset for the validation of numerical models and atmospheric reanalysis products.

scholarly journals Arctic Ocean circulation and variability – advection and external forcing encounter constraints and local processes

2011 ◽  
Vol 8 (6) ◽  
pp. 2313-2376 ◽  
Author(s):  
B. Rudels
Keyword(s):  
Sea Ice ◽  
Arctic Ocean ◽  
Ocean Circulation ◽  
Barents Sea ◽  
Atlantic Water ◽  
The Arctic ◽  
Fram Strait ◽  
Intermediate Layers ◽  
The Arctic Ocean ◽  
Almost All

Abstract. The first hydrographic data from the Arctic Ocean, the section from the Laptev Sea to the passage between Greenland and Svalbard obtained by Nansen on the drift by Fram 1893–1896, aptly illustrate the main features of Arctic Ocean oceanography and indicate possible processes active in transforming the water masses in the Arctic Ocean. Many, perhaps most, of these processes were identified already by Nansen, who put his mark on almost all subsequent research in the Arctic Ocean. Here we shall revisit some key questions and follow how our understanding has evolved from the early 20th century to present. What questions, if any, can now be regarded as solved and which remain still open? Five different but connected topics will be discussed: (1) The low salinity surface layer and the storage and export of freshwater. (2) The vertical heat transfer from the Atlantic water to sea ice and to the atmosphere. (3) The circulation and mixing of the two Atlantic inflow branches. (4) The formation and circulation of deep and bottom waters in the Arctic Ocean. (5) The exchanges through Fram Strait. Foci will be on the potential effects of increased freshwater input and reduced sea ice export on the freshwater storage and residence time in the Arctic Ocean, on the deep waters of the Makarov Basin and on the circulation and relative importance of the two inflows, over the Barents Sea and through Fram Strait, for the distribution of heat in the intermediate layers of the Arctic Ocean.

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