scholarly journals High-frequency climate variability in the Holocene from a coastal-dome ice core in east-central Greenland

2020 ◽  
Vol 16 (4) ◽  
pp. 1369-1386
Author(s):  
Abigail G. Hughes ◽  
Tyler R. Jones ◽  
Bo M. Vinther ◽  
Vasileios Gkinis ◽  
C. Max Stevens ◽  
...  
Keyword(s):  
Sea Ice ◽  
Regional Climate ◽  
Ice Core ◽  
Sea Surface ◽  
Climate Information ◽  
East Central ◽  
Surface Conditions ◽  
The Holocene ◽  
Isotope Record ◽  
Water Isotope

Abstract. An ice core drilled on the Renland ice cap in east-central Greenland contains a continuous climate record dating through the last glacial period. The Renland record is valuable because the coastal environment is more likely to reflect regional sea surface conditions compared to inland Greenland ice cores that capture synoptic variability. Here we present the δ18O water isotope record for the Holocene, in which decadal-scale climate information is retained for the last 8 kyr, while the annual water isotope signal is preserved throughout the last 2.6 kyr. To investigate regional climate information preserved in the water isotope record, we apply spectral analysis techniques to a 300-year moving window to determine the mean strength of varying frequency bands through time. We find that the strength of 15–20-year δ18O variability exhibits a millennial-scale signal in line with the well-known Bond events. Comparison to other North Atlantic proxy records suggests that the 15–20-year variability may reflect fluctuating sea surface conditions throughout the Holocene, driven by changes in the strength of the Atlantic Meridional Overturning Circulation. Additional analysis of the seasonal signal over the last 2.6 kyr reveals that the winter δ18O signal has experienced a decreasing trend, while the summer signal has predominantly remained stable. The winter trend may correspond to an increase in Arctic sea ice cover, which is driven by a decrease in total annual insolation, and is also likely influenced by regional climate variables such as atmospheric and oceanic circulation. In the context of anthropogenic climate change, the winter trend may have important implications for feedback processes as sea ice retreats in the Arctic.

scholarly journals High-frequency climate oscillations in the Holocene from a coastal-dome ice core in east central Greenland

2020 ◽  
Author(s):  
Abigail G. Hughes ◽  
Tyler R. Jones ◽  
Bo M. Vinther ◽  
Vasileios Gkinis ◽  
C. Max Stevens ◽  
...  
Keyword(s):  
Sea Ice ◽  
Ice Core ◽  
The Arctic ◽  
Climate Information ◽  
East Central ◽  
The Holocene ◽  
Frequency Bands ◽  
Isotope Record ◽  
The Mean ◽  
Water Isotope

Abstract. An ice core drilled on the Renland Ice Cap in east-central Greenland contains a continuous climate record dating through the last glacial period. The Renland record is valuable because the coastal environment is more likely to reflect regional sea surface conditions, compared to inland Greenland ice cores that capture synoptic variability. Here we present the δ18O water isotope record for the Holocene, in which decadal-scale climate information is retained for the last 8 ka, and the annual water isotope signal is preserved throughout the last 2.6 ka. To investigate regional climate information preserved in the water isotope record, we apply spectral analysis techniques to a 300-year moving window to determine the mean strength of varying frequency bands through time. The strength of interannual frequency bands decays rapidly, but we find that the mean 15–20 year δ18O variability exhibits a millennial-scale cycle in line with the well-known Bond Cycle. Comparison to other North Atlantic proxy records suggests that the 15–20 year variability may reflect fluctuating sea ice conditions throughout the Holocene, driven by changes in the strength of the Atlantic Meridional Overturning Circulation. Additional analysis of the seasonal signal over the last 2.6 ka reveals that the winter δ18O signal has experienced a decreasing trend, while the summer signal has predominantly remained stable. The winter trend likely corresponds to an increase in Arctic sea ice cover, driven by a decrease in total annual insolation. In the context of anthropogenic climate change, the winter trend may have important implications for feedback processes as sea ice retreats in the Arctic.

Modern warming exceeds sea surface temperatures of the Holocene Thermal Maximum in Kongsfjorden, Svalbard

2021 ◽  
Author(s):  
Harikrishnan Guruvayoorappan ◽  
Arto Miettinen ◽  
Dmitry Divine ◽  
Rahul Mohan
Keyword(s):  
High Resolution ◽  
Sea Ice ◽  
Sea Surface ◽  
The Arctic ◽  
Sea Surface Temperatures ◽  
Surface Conditions ◽  
The Holocene ◽  
Holocene Thermal Maximum ◽  
Thermal Maximum ◽  
Ice Conditions

<p>Certain past climatic events act as an analogue for future climatic conditions. The Holocene epoch featured a number of climatic variations of which Holocene Thermal Maximum (HTM) stands out as a recognizable phenomenon, especially in the North Atlantic and the Arctic. Similar to modern warming, HTM in Svalbard recorded extreme warmth along with intense deglaciation and sea ice retreat. Therefore, predictions of future climate using HTM depends on understanding the changes in interactions between ocean, sea ice, and atmospheric conditions. While many studies exist on this period, only few have reconstructed ocean surface conditions in the Arctic at high resolution. Here we present the first diatom-based high-resolution quantitative reconstruction of sea surface conditions from Kongsfjorden, Svalbard covering the period of ca. 10.5 to 7.5 cal. kyr BP. Our reconstructions of sea surface temperature (SST) and sea ice conditions are based on diatom microfossil records from a 454 cm long marine sediment core from Kongsfjorden, Svalbard. The section from 454 to 300 cm was used for reconstructions owing to the lack of availability of diatom microfossils. Owing to their high sensitivity towards SST and sea ice, diatoms act as excellent proxies of these environmental conditions in the past. The SST record from Kongsfjorden reveals moderately warm open water conditions and highly variable sea ice conditions during the HTM. The SST achieves maximum values during the early Holocene insolation maxima ca. 10.5 to 7.5 cal. kyr BP, followed by a slow cooling trend simultaneously with the decreasing insolation intensity. Our results emphasize the regional heterogeneity observed in ocean surfaces during the HTM and how modern warming in the study area has already reached sea surface temperatures comparable to the HTM. </p>

scholarly journals Supplementary material to "Climate information preserved in seasonal water isotope at NEEM: relationships with temperature, circulation and sea ice"

2018 ◽  
Author(s):  
Minjie Zheng ◽  
Jesper Sjolte ◽  
Florian Adolphi ◽  
Bo Møllesøe Vinther ◽  
Hans Christian Steen-Larsen ◽  
...  
Keyword(s):  
Sea Ice ◽  
Climate Information ◽  
Supplementary Material ◽  
Water Isotope

Palynological evidence of sea-surface conditions in the Barents Sea off northeast Svalbard during the postglacial period

2020 ◽  
pp. 1-15
Author(s):  
Camille Brice ◽  
Anne de Vernal ◽  
Elena Ivanova ◽  
Simon van Bellen ◽  
Nicolas Van Nieuwenhove
Keyword(s):  
Sea Ice ◽  
Surface Waters ◽  
Barents Sea ◽  
Ice Cover ◽  
Atlantic Water ◽  
Transitional Period ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Surface Conditions ◽  
The Barents Sea

Abstract Postglacial changes in sea-surface conditions, including sea-ice cover, summer temperature, salinity, and productivity were reconstructed from the analyses of dinocyst assemblages in core S2528 collected in the northwestern Barents Sea. The results show glaciomarine-type conditions until about 11,300 ± 300 cal yr BP and limited influence of Atlantic water at the surface into the Barents Sea possibly due to the proximity of the Svalbard-Barents Sea ice sheet. This was followed by a transitional period generally characterized by cold conditions with dense sea-ice cover and low-salinity pulses likely related to episodic freshwater or meltwater discharge, which lasted until 8700 ± 700 cal yr BP. The onset of “interglacial” conditions in surface waters was marked by a major change in dinocyst assemblages, from dominant heterotrophic to dominant phototrophic taxa. Until 4100 ± 150 cal yr BP, however, sea-surface conditions remained cold, while sea-surface salinity and sea-ice cover recorded large amplitude variations. By ~4000 cal yr BP optimum sea-surface temperature of up to 4°C in summer and maximum salinity of ~34 psu suggest enhanced influence of Atlantic water, and productivity reached up to 150 gC/m2/yr. After 2200 ± 1300 cal yr BP, a distinct cooling trend accompanied by sea-ice spreading characterized surface waters. Hence, during the Holocene, with exception of an interval spanning about 4000 to 2000 cal yr BP, the northern Barents Sea experienced harsh environments, relatively low productivity, and unstable conditions probably unsuitable for human settlements.

scholarly journals Evolution of sea‐surface conditions on the northwestern Greenland margin during the Holocene

2019 ◽  
Vol 34 (7) ◽  
pp. 569-580 ◽  
Author(s):  
Myriam Caron ◽  
André Rochon ◽  
Jean‐Carlos Montero‐Serrano ◽  
Guillaume St‐Onge
Keyword(s):  
Sea Surface ◽  
Surface Conditions ◽  
The Holocene ◽  
Greenland Margin

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.

Sea surface conditions in the southern Nordic Seas during the Holocene based on dinoflagellate cyst assemblages

The Holocene ◽  
2016 ◽  
Vol 26 (5) ◽  
pp. 722-735 ◽  
Author(s):  
Nicolas Van Nieuwenhove ◽  
Astrid Baumann ◽  
Jens Matthiessen ◽  
Sophie Bonnet ◽  
Anne de Vernal
Keyword(s):  
Sea Surface ◽  
Nordic Seas ◽  
Surface Conditions ◽  
The Holocene ◽  
Dinoflagellate Cyst

Land-Ocean interactions at the southwest Greenland margin during the Holocene

2020 ◽  
Author(s):  
Estelle Allan ◽  
Anne de Vernal ◽  
Marit-Solveig Seidenkrantz ◽  
Claude Hillaire-Marcel ◽  
Christof Pearce ◽  
...  
Keyword(s):  
Transfer Functions ◽  
Greenland Ice Sheet ◽  
Sea Surface ◽  
Human Occupation ◽  
Ice Dynamics ◽  
Surface Conditions ◽  
The Holocene ◽  
High Productivity ◽  
Holocene Thermal Maximum ◽  
Greenland Margin

<p>Palynomorph analysis of marine cores raised off Nuuk (southwestern Greenland) provided records of sea-surface conditions and climate-ocean-ice dynamics at centennial resolution over the last 12,000 years. Transfer functions using dinocyst assemblages provided information about the sea-ice cover, seasonal sea-surface temperature (SST) and salinity (SSS), as well as primary productivity. At about 10,000 cal. years ago, an increase in species diversity and the rapid increase of phototrophic taxa (light-dependent), marks the onset of interglacial conditions, with summer temperature increasing up to ~10°C during the Holocene Thermal Maximum (HTM). Low SSS and high productivity conditions are recorded during the interval, which we associate to increased meltwater and nutrient input from the Greenland Ice Sheet. After ~5000 cal. years BP, the decrease of phototrophic taxa marks a two-steps cooling associated with the Neoglacial trend. Since ~2000 cal. years BP, an increase in the high-frequency variability of sea surface conditions is noticeable. The second step change towards colder and more unstable conditions starting about 3000 cal. years BP coincides with the disappearance of the Saqqaq culture. The gap of human occupation in western Greenland, between the Dorset and the Norse settlements, i.e., from ca. 2000 to 1000 cal. years BP, may thus be linked to the highly unstable conditions in surface waters.</p>

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