A shift to predominant multi-year sea ice conditions in the Baffin Bay and North Atlantic Ocean during the Holocene-Glacial transition inferred from the EGRIP ice core

2021 ◽  
Author(s):  
Delia Segato ◽  
Francois Burgay ◽  
Niccolò Maffezzoli ◽  
Azzurra Spagnesi ◽  
Clara Turetta ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Sea Ice ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Ice Core ◽  
Ice Cores ◽  
Arctic Sea Ice ◽  
The Holocene ◽  
Baffin Bay ◽  
Ice Conditions

<p>Arctic sea ice has been melting at unprecedented rates in the past decades. Understanding past sea ice variability is of paramount importance to contextualize recent changes and constrain global climate models. Bromine enrichment (Br<sub>enr</sub>), relative to sea-water ratio, has been introduced as a proxy of first-year sea ice conditions within the ocean region influencing the ice core location (Spolaor et al., 2013). Br<sub>enr</sub> has been measured in ice cores from Greenland, that is the NEEM and RECAP cores. NEEM sea ice proxies are influenced by the region of the Canadian Arctic and Baffin Bay, while for the RECAP core it is mainly the North Atlantic Ocean. In this study we present the first high-resolution record of bromine enrichment from the EGRIP ice core in Greenland for the last 15.7 kyr BP, covering the Holocene-Glacial transition.</p><p>From preliminary back-trajectory analyses we suggest that EGRIP sea ice proxy sources are located in a wide region in the Baffin Bay and North Atlantic Ocean. We find EGRIP Br<sub>enr</sub> values of ~1 during cold periods, that is the Younger Dryas (12.9 – 11.7 kyr BP) and the last part of the Oldest Dryas (15.7 – 14.7 kyr BP), which we associate with predominant multi-year sea ice conditions. During warmer periods, instead, we observe higher Br<sub>enr</sub> values, ~3 for the Bølling-Allerød period (14.7 – 12.9 kyr BP) and progressively higher values from the early Holocene onwards, likely associated with an increased seasonal sea ice area. EGRIP Br<sub>enr</sub> is consistent with NEEM and RECAP records and it has the potential to extend our knowledge on Arctic past sea ice variability.</p><p><strong> </strong></p><p><strong>Bibliography</strong></p><p>Spolaor, A., Vallelonga, P., Plane, J. M. C., Kehrwald, N., Gabrieli, J., Varin, C., Turetta, C., Cozzi, G., Kumar, R., Boutron, C., and Barbante, C.: Halogen species record Antarctic sea ice extent over glacial–interglacial periods, Atmos. Chem. Phys., 13, 6623–6635, https://doi.org/10.5194/acp-13-6623-2013, 2013.</p>

scholarly journals Impact of model resolution on Arctic sea ice and North Atlantic Ocean heat transport

2019 ◽  
Vol 53 (7-8) ◽  
pp. 4989-5017 ◽  
Author(s):  
David Docquier ◽  
Jeremy P. Grist ◽  
Malcolm J. Roberts ◽  
Christopher D. Roberts ◽  
Tido Semmler ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Sea Ice ◽  
Heat Transport ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Arctic Sea Ice ◽  
Model Resolution ◽  
Ocean Heat Transport ◽  
Arctic Sea

Dinocyst-based reconstructions of sea ice cover concentration during the Holocene in the Arctic Ocean, the northern North Atlantic Ocean and its adjacent seas

2013 ◽  
Vol 79 ◽  
pp. 111-121 ◽  
Author(s):  
Anne de Vernal ◽  
Claude Hillaire-Marcel ◽  
André Rochon ◽  
Bianca Fréchette ◽  
Maryse Henry ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Sea Ice ◽  
Arctic Ocean ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Ice Cover ◽  
The Arctic ◽  
The Holocene ◽  
The Arctic Ocean

scholarly journals Unprecedented decline of Arctic sea ice outflow in 2018

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

Abstract Fram Strait is the major gateway connecting the Arctic Ocean and North Atlantic Ocean, where nearly 90% of the sea ice export from the Arctic Ocean takes place. The exported sea ice is a large source of freshwater to the Nordic Seas and Subpolar North Atlantic, thereby preconditioning European climate and deep water formation in the downstream North Atlantic Ocean. Here we show that in 2018, the ice export through Fram Strait showed an unprecedented decline since the early 1990s. The 2018 ice export was reduced to less than 40% relative to that between 2000 and 2017, and amounted to just 25% of the 1990s. The minimum export was attributed to regional sea ice-ocean processes driven by an anomalous atmospheric circulation over the Atlantic sector of the Arctic. The anomalous circulation caused a stagnation of southward sea ice drift, causing a sudden drop of sea ice thickness north of the Fram Strait due to local heat supply from the ocean. The result indicates that a drastic change of the freshwater cycle and its environmental consequences happen not only through ongoing Arctic-wide ice thinning, but also by regional scale atmospheric anomalies in the Atlantic sector on annual timescales.

scholarly journals A 120 000-year record of sea ice in the North Atlantic?

2019 ◽  
Vol 15 (6) ◽  
pp. 2031-2051 ◽  
Author(s):  
Niccolò Maffezzoli ◽  
Paul Vallelonga ◽  
Ross Edwards ◽  
Alfonso Saiz-Lopez ◽  
Clara Turetta ◽  
...  
Keyword(s):  
Sea Ice ◽  
North Atlantic ◽  
Ice Core ◽  
Arctic Sea Ice ◽  
First Year ◽  
Sea Ice Extent ◽  
Nordic Seas ◽  
The North ◽  
Arctic Sea ◽  
The North Atlantic

Abstract. Although it has been demonstrated that the speed and magnitude of the recent Arctic sea ice decline is unprecedented for the past 1450 years, few records are available to provide a paleoclimate context for Arctic sea ice extent. Bromine enrichment in ice cores has been suggested to indicate the extent of newly formed sea ice areas. Despite the similarities among sea ice indicators and ice core bromine enrichment records, uncertainties still exist regarding the quantitative linkages between bromine reactive chemistry and the first-year sea ice surfaces. Here we present a 120 000-year record of bromine enrichment from the RECAP (REnland ice CAP) ice core, coastal east Greenland, and interpret it as a record of first-year sea ice. We compare it to existing sea ice records from marine cores and tentatively reconstruct past sea ice conditions in the North Atlantic as far north as the Fram Strait (50–85∘ N). Our interpretation implies that during the last deglaciation, the transition from multi-year to first-year sea ice started at ∼17.5 ka, synchronously with sea ice reductions observed in the eastern Nordic Seas and with the increase in North Atlantic ocean temperature. First-year sea ice reached its maximum at 12.4–11.8 ka during the Younger Dryas, after which open-water conditions started to dominate, consistent with sea ice records from the eastern Nordic Seas and the North Icelandic shelf. Our results show that over the last 120 000 years, multi-year sea ice extent was greatest during Marine Isotope Stage (MIS) 2 and possibly during MIS 4, with more extended first-year sea ice during MIS 3 and MIS 5. Sea ice extent during the Holocene (MIS 1) has been less than at any time in the last 120 000 years.

scholarly journals High-resolution mineral dust and sea ice proxy records from the Talos Dome ice core

2013 ◽  
Vol 9 (6) ◽  
pp. 2789-2807 ◽  
Author(s):  
S. Schüpbach ◽  
U. Federer ◽  
P. R. Kaufmann ◽  
S. Albani ◽  
C. Barbante ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Sea Ice ◽  
Ross Sea ◽  
Transport Model ◽  
Mineral Dust ◽  
Ice Core ◽  
Ice Cores ◽  
Last Interglacial ◽  
The Holocene ◽  
Proxy Records

Abstract. In this study we report on new non-sea salt calcium (nssCa2+, mineral dust proxy) and sea salt sodium (ssNa+, sea ice proxy) records along the East Antarctic Talos Dome deep ice core in centennial resolution reaching back 150 thousand years (ka) before present. During glacial conditions nssCa2+ fluxes in Talos Dome are strongly related to temperature as has been observed before in other deep Antarctic ice core records, and has been associated with synchronous changes in the main source region (southern South America) during climate variations in the last glacial. However, during warmer climate conditions Talos Dome mineral dust input is clearly elevated compared to other records mainly due to the contribution of additional local dust sources in the Ross Sea area. Based on a simple transport model, we compare nssCa2+ fluxes of different East Antarctic ice cores. From this multi-site comparison we conclude that changes in transport efficiency or atmospheric lifetime of dust particles do have a minor effect compared to source strength changes on the large-scale concentration changes observed in Antarctic ice cores during climate variations of the past 150 ka. Our transport model applied on ice core data is further validated by climate model data. The availability of multiple East Antarctic nssCa2+ records also allows for a revision of a former estimate on the atmospheric CO2 sensitivity to reduced dust induced iron fertilisation in the Southern Ocean during the transition from the Last Glacial Maximum to the Holocene (T1). While a former estimate based on the EPICA Dome C (EDC) record only suggested 20 ppm, we find that reduced dust induced iron fertilisation in the Southern Ocean may be responsible for up to 40 ppm of the total atmospheric CO2 increase during T1. During the last interglacial, ssNa+ levels of EDC and EPICA Dronning Maud Land (EDML) are only half of the Holocene levels, in line with higher temperatures during that period, indicating much reduced sea ice extent in the Atlantic as well as the Indian Ocean sector of the Southern Ocean. In contrast, Holocene ssNa+ flux in Talos Dome is about the same as during the last interglacial, indicating that there was similar ice cover present in the Ross Sea area during MIS 5.5 as during the Holocene.

Abrupt changes in the Asian southwest monsoon during the Holocene and their links to the North Atlantic Ocean

Nature ◽  
2003 ◽  
Vol 421 (6921) ◽  
pp. 354-357 ◽  
Author(s):  
Anil K. Gupta ◽  
David M. Anderson ◽  
Jonathan T. Overpeck
Keyword(s):  
Atlantic Ocean ◽  
North Atlantic ◽  
North Atlantic Ocean ◽  
Southwest Monsoon ◽  
The Holocene ◽  
The North ◽  
Abrupt Changes ◽  
The North Atlantic

scholarly journals Sea ice and pollution-modulated changes in Greenland ice core methanesulfonate and bromine

2017 ◽  
Vol 13 (1) ◽  
pp. 39-59 ◽  
Author(s):  
Olivia J. Maselli ◽  
Nathan J. Chellman ◽  
Mackenzie Grieman ◽  
Lawrence Layman ◽  
Joseph R. McConnell ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ice Core ◽  
Chemical Species ◽  
Greenland Ice Sheet ◽  
Ice Cores ◽  
Arctic Sea Ice ◽  
Sea Ice Extent ◽  
Back Trajectories ◽  
Future Evolution ◽  
Source Regions

Abstract. Reconstruction of past changes in Arctic sea ice extent may be critical for understanding its future evolution. Methanesulfonate (MSA) and bromine concentrations preserved in ice cores have both been proposed as indicators of past sea ice conditions. In this study, two ice cores from central and north-eastern Greenland were analysed at sub-annual resolution for MSA (CH3SO3H) and bromine, covering the time period 1750–2010. We examine correlations between ice core MSA and the HadISST1 ICE sea ice dataset and consult back trajectories to infer the likely source regions. A strong correlation between the low-frequency MSA and bromine records during pre-industrial times indicates that both chemical species are likely linked to processes occurring on or near sea ice in the same source regions. The positive correlation between ice core MSA and bromine persists until the mid-20th century, when the acidity of Greenland ice begins to increase markedly due to increased fossil fuel emissions. After that time, MSA levels decrease as a result of declining sea ice extent but bromine levels increase. We consider several possible explanations and ultimately suggest that increased acidity, specifically nitric acid, of snow on sea ice stimulates the release of reactive Br from sea ice, resulting in increased transport and deposition on the Greenland ice sheet.

High Arctic Polynyas in a Changing Climate

2020 ◽  
Author(s):  
Rebecca Jackson ◽  
Anna Bang Kvorning ◽  
Christof Pearce ◽  
Marit-Solveig Seidenkrantz ◽  
Sofia Ribeiro
Keyword(s):  
Sea Ice ◽  
Indigenous Communities ◽  
High Arctic ◽  
Arctic Sea Ice ◽  
Holistic View ◽  
The Holocene ◽  
Changing Climate ◽  
New Findings ◽  
North Water ◽  
Ice Conditions

<p>Polynyas, areas of open water in the otherwise sea-ice dominated high Arctic, are vital oases for biological productivity, supporting a plethora of marine mammals and birds that in turn sustain indigenous communities. Polynyas are not, however, consistent features. Beyond the observational era, little to nothing is known about their past dynamics and equally, about their resilience to emerging changes in Arctic sea-ice conditions.</p><p>Recent paleoceanographic reconstructions of the North Water in northern Baffin Bay, the largest of the high Arctic polynyas, indicate that the polynya contracted in response to warm climatic intervals during the Holocene (e.g. Roman Warm Period). In contrast, the onset of stable North Water polynya formation acted to suppress northward incursion of warm Atlantic-sourced waters. This highlighted not only the sensitivity of polynyas to past climatic changes, but the role their formation plays in mediating water column dynamics and ocean circulation.</p><p>These new findings provided the rationale for the MSCA project ‘POLARC: High Arctic Polynyas in a Changing Climate’, to investigate the Holocene dynamics of other high Arctic polynyas forming off the east Greenland coast. New marine sedimentary archives and a multiproxy approach will be used to reconstruct productivity, sea-ice conditions and bottom water conditions, capturing a holistic view of these systems and their interaction with climatic and oceanographic variation during the Holocene (11,700 years BP to present). We present here preliminary paleoceanographic reconstructions of the Sirius Water, the first Holocene record from this polynya region, as well as plans for model-data comparisons in key polynya regions with the aim of constraining the past and better predicting the future of these phenomena.</p>

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