Reconstructing climate variability from Greenland ice sheet accumulation: An ERA40 study

Climate variability of the Arctic region has been investigated by means of temperature reconstructions based on proxies from various climate archives around the Arctic, compiled over the last 2000a in the so called Arctic2k record. However, the representativeness of the Arctic2k reconstruction for central Greenland remains unclear, since only a few ice cores have been included in the reconstruction, and observations from the Greenland Ice Sheet (GIC) report ambiguous warming trends for the end of the 20th and the beginning of the 21st century which are not displayed by Arctic2k. Today, the GIC experiences periods with temperatures close to or above the freezing point at high elevations, area-wide melting and mass loss. In order to assess the recent warming as signature of global climate change, records of past climate changes with appropriate temporal and spatial coverage can serve as a benchmark for naturally driven climate variability. Instrumental records for Greenland are short and geographically sparse, and existing temperature reconstructions from single ice cores are noisy, leading to an inconclusive assessment of the recent warming for Greenland.Here, we provide a Greenland firn-core stack covering the time span of the last millennium until the first decade of the 21st century in unprecedented quality by re-drilling as well as analyzing 16 existing firn core sites. We find a strong decadal to bi-decadal natural variability in the record, and, while the record exhibits several warming events with trends that show a similar amplitude as the recent one, we find that the recent absolute values of stable oxygen isotope composition are unprecedented for the last 1000 years.&#160;Comparing our Greenland record with the Arctic 2k temperature reconstruction shows that the correlation between the two records changes throughout the last millennium. While in the periods of 1200-1300 and 1400-1650 CE the records correlate positively, between 1300 and 1400 and 1650-1700 CE shorter periods with negative correlation are found. Since then the correlation is characterized by alternation between positive and zero correlation, with a drop towards negative values at the end of the 20th century. Including re-analysis data, we hypothesize that the climate on top of the GIC was decoupled from the surrounding Arctic for the last decades, leading to the observed mismatch in observations of warming trends.We suggest that the recently observed Greenland temperatures are a superposition of a strong natural variability with an anthropogenic long-term trend. Our findings illustrate that global warming has reached the interior of the Greenland ice sheet, which will have implications for its surface mass balance and Greenland&#8217;s future contribution to sea level rise.Our record complements the Arctic 2k record to a profound view on the Arctic climate variability, where regional compilations may not be representative for specific areas.

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Impact of freshwater discharge from the Greenland ice sheet on North Atlantic climate variability

Theoretical and Applied Climatology ◽

10.1007/s00704-012-0699-6 ◽

2012 ◽

Vol 112 (1-2) ◽

pp. 29-43 ◽

Cited By ~ 2

Author(s):

Soon-Il An ◽

Hyerim Kim ◽

Baek-Min Kim

Keyword(s):

Climate Variability ◽

North Atlantic ◽

Ice Sheet ◽

Greenland Ice Sheet ◽

Freshwater Discharge ◽

North Atlantic Climate

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Aspects of climate variability in the North Atlantic sector: Discussion and relation to the Greenland Ice Sheet Project 2 high-resolution isotopic signal

Journal of Geophysical Research Atmospheres ◽

10.1029/96jc02401 ◽

1997 ◽

Vol 102 (C12) ◽

pp. 26333-26344 ◽

Cited By ~ 47

Author(s):

L. K. Barlow ◽

J. C. Rogers ◽

M. C. Serreze ◽

R. G. Barry

Keyword(s):

High Resolution ◽

Climate Variability ◽

North Atlantic ◽

Ice Sheet ◽

Greenland Ice Sheet ◽

Atlantic Sector ◽

The North ◽

The North Atlantic ◽

Isotopic Signal

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The Nioghalvfjerdsfjorden glacier project, North-East Greenland: a study of ice sheet response to climatic change

Geological Survey of Denmark and Greenland Bulletin ◽

10.34194/ggub.v176.5073 ◽

1997 ◽

pp. 95-103 ◽

Cited By ~ 5

Author(s):

Henrik Højmark Thomsen ◽

Niels Reeh ◽

Ole B. Olesen ◽

Carl Egede Bøggilde ◽

Wolfgang Starzer ◽

...

Keyword(s):

Climatic Change ◽

Ice Sheet ◽

Greenland Ice Sheet ◽

East Greenland ◽

Changing Climate ◽

North East ◽

Integrated Research ◽

Research Themes ◽

Advance Research ◽

Inland Ice

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Højmark Thomsen, H., Reeh, N., Olesen, O. B., Egede Bøggilde, C., Starzer, W., Weidick, A., & Higgins, A. K. (1997). The Nioghalvfjerdsfjorden glacier project, North-East Greenland: a study of ice sheet response to climatic change. Geology of Greenland Survey Bulletin, 176, 95-103. https://doi.org/10.34194/ggub.v176.5073 _______________ Glaciological research was initiated in 1996 on the floating glacier tongue filling Nioghalvfjerdsfjorden in NorthEast Greenland (Fig. 1), with the aim of acquiring a better understanding of the response of the Greenland ice sheet (Inland Ice) to changing climate, and the implications for future sea level. The research is part of a three year project (1996–98) to advance research into the basic processes that contribute to changes in the ocean volume with a changing climate. Five nations are participants in the project, which is supported by the European Community (EC) Environment and Climate Programme. The Geological Survey of Denmark and Greenland (GEUS) and the Danish Polar Center are the Danish partners in the project, both with integrated research themes concentrated on and around Nioghalvfjerdsfjorden.

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Could climate engineering save the Greenland Ice Sheet?

Climanosco Research Articles - https://www.climanosco.org/collection/climate-change-and-its-impacts/ ◽

10.37207/cra.1.10 ◽

2016 ◽

Author(s):

Patrick J. Applegate ◽

K. Keller

Keyword(s):

Sea Level Rise ◽

Greenhouse Gas Emissions ◽

Greenhouse Gas ◽

Sea Level ◽

Computer Model ◽

Ice Sheet ◽

Greenland Ice Sheet ◽

Upper Atmosphere ◽

Climate Engineering ◽

Air Temperatures

Engineering the climate through albedo modification (AM) could slow, but probably would not stop, melting of the Greenland Ice Sheet. Albedo modification is a technology that could reduce surface air temperatures through putting reflective particles into the upper atmosphere. AM has never been tested, but it might reduce surface air temperatures faster and more cheaply than reducing greenhouse gas emissions. Some scientists claim that AM would also prevent or reverse sea-level rise. But, are these claims true? The Greenland Ice Sheet will melt faster at higher temperatures, adding to sea-level rise. However, it's not clear that reducing temperatures through AM will stop or reverse sea-level rise due to Greenland Ice Sheet melting. We used a computer model of the Greenland Ice Sheet to examine its contributions to future sea level rise, with and without AM. Our results show that AM would probably reduce the rate of sea-level rise from the Greenland Ice Sheet. However, sea-level rise would likely continue even with AM, and the ice sheet would not regrow quickly. Albedo modification might buy time to prepare for sea-level rise, but problems could arise if policymakers assume that AM will stop sea-level rise completely.

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Response of the Energy Balance on the Margin of the Greenland Ice Sheet to Temperature Changes

Journal of Glaciology ◽

10.1017/s0022143000009461 ◽

1990 ◽

Vol 36 (123) ◽

pp. 217-221 ◽

Cited By ~ 25

Author(s):

Roger J. Braithwaite ◽

Ole B. Olesen

Keyword(s):

Heat Flux ◽

Energy Balance ◽

Air Temperature ◽

Sensible Heat Flux ◽

Ice Sheet ◽

Temperature Response ◽

Greenland Ice Sheet ◽

Energy Balance Model ◽

Balance Model ◽

Sensible Heat

AbstractDaily ice ablation on two outlet glaciers from the Greenland ice sheet, Nordbogletscher (1979–83) and Qamanârssûp sermia (1980–86), is related to air temperature by a linear regression equation. Analysis of this ablation-temperature equation with the help of a simple energy-balance model shows that sensible-heat flux has the greatest temperature response and accounts for about one-half of the temperature response of ablation. Net radiation accounts for about one-quarter of the temperature response of ablation, and latent-heat flux and errors account for the remainder. The temperature response of sensible-heat flux at QQamanârssûp sermia is greater than at Nordbogletscher mainly due to higher average wind speeds. The association of high winds with high temperatures during Föhn events further increases sensible-heat flux. The energy-balance model shows that ablation from a snow surface is only about half that from an ice surface at the same air temperature.

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Melt season duration and ice layer formation on the Greenland ice sheet, 2000–2004

Journal of Geophysical Research Atmospheres ◽

10.1029/2007jf000760 ◽

2007 ◽

Vol 112 (F4) ◽

Cited By ~ 28

Author(s):

Libo Wang ◽

Martin Sharp ◽

Benoit Rivard ◽

Konrad Steffen

Keyword(s):

Ice Sheet ◽

Greenland Ice Sheet ◽

Layer Formation

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Large subglacial source of mercury from the southwestern margin of the Greenland Ice Sheet

Nature Geoscience ◽

10.1038/s41561-021-00753-w ◽

2021 ◽

Author(s):

Jon R. Hawkings ◽

Benjamin S. Linhoff ◽

Jemma L. Wadham ◽

Marek Stibal ◽

Carl H. Lamborg ◽

...

Keyword(s):

Natural Waters ◽

Inorganic Mercury ◽

Ice Sheet ◽

Greenland Ice Sheet ◽

Annual Runoff ◽

Arctic Ecosystems ◽

High Mercury ◽

Southwestern Margin ◽

High Concentrations ◽

Dissolved Mercury

AbstractThe Greenland Ice Sheet is currently not accounted for in Arctic mercury budgets, despite large and increasing annual runoff to the ocean and the socio-economic concerns of high mercury levels in Arctic organisms. Here we present concentrations of mercury in meltwaters from three glacial catchments on the southwestern margin of the Greenland Ice Sheet and evaluate the export of mercury to downstream fjords based on samples collected during summer ablation seasons. We show that concentrations of dissolved mercury are among the highest recorded in natural waters and mercury yields from these glacial catchments (521–3,300 mmol km−2 year−1) are two orders of magnitude higher than from Arctic rivers (4–20 mmol km−2 year−1). Fluxes of dissolved mercury from the southwestern region of Greenland are estimated to be globally significant (15.4–212 kmol year−1), accounting for about 10% of the estimated global riverine flux, and include export of bioaccumulating methylmercury (0.31–1.97 kmol year−1). High dissolved mercury concentrations (~20 pM inorganic mercury and ~2 pM methylmercury) were found to persist across salinity gradients of fjords. Mean particulate mercury concentrations were among the highest recorded in the literature (~51,000 pM), and dissolved mercury concentrations in runoff exceed reported surface snow and ice values. These results suggest a geological source of mercury at the ice sheet bed. The high concentrations of mercury and its large export to the downstream fjords have important implications for Arctic ecosystems, highlighting an urgent need to better understand mercury dynamics in ice sheet runoff under global warming.

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