Holocene temperature variations inferred from Antarctic ice cores

We have reconstructed temperature changes over the past 15 000 years from ice-core data in Antarctica. We used measurements of the D/H isotope ratio in ice as a proxy of temperature for central sites (Vostok, Dome C and Komsomolskaya; as well as coastal sites (D47, D15 and D10). First, we examined the dating of each core and built up a common temporal framework for the ensemble of the data. Secondly, we addressed the problem of inferring small-amplitude temperature fluctuations from the isotope data, in the light of noise-generating mechanisms involved in snow deposition. Temperature was reconstructed so as to minimize distortion created by the sampling of ice cores in the field. The seven ice cores studied yield an average temperature curve which can be put in perspective with nearby paleoclimatic records. The early Holocene experienced climates warmer than today by 1-2°C. The late Holocene period shows more discernible, shorter-duration, temperature fluctuations, superimposed on a fairly stable "base-line" temperature.

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Holocene temperature variations inferred from Antarctic ice cores

Annals of Glaciology ◽

10.1017/s0260305500016803 ◽

1994 ◽

Vol 20 ◽

pp. 427-436 ◽

Cited By ~ 1

Author(s):

P. Ciais ◽

J. Jouzel ◽

J. R. Petit ◽

V. Lipenkov ◽

J. W. C. White

Keyword(s):

Late Holocene ◽

Ice Core ◽

Ice Cores ◽

Temperature Fluctuations ◽

Base Line ◽

Temperature Changes ◽

Average Temperature ◽

The Past ◽

Reconstructed Temperature ◽

Line Temperature

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Differing pre-industrial cooling trends between tree-rings and lower-resolution temperature proxies

10.5194/cp-2019-41 ◽

2019 ◽

Cited By ~ 3

Author(s):

Lara Klippel ◽

Scott St. George ◽

Ulf Büntgen ◽

Paul J. Krusic ◽

Jan Esper

Keyword(s):

Tree Ring ◽

Ice Core ◽

Ice Cores ◽

Temperature Changes ◽

The Past ◽

Proxy Records ◽

Temperature Trends ◽

Long Term Trends ◽

Cooling Trend

Abstract. The 692 proxy records of the new PAGES 2k compilation offer an unprecedented opportunity to study regional to global temperature trends associated with orbitally-driven changes in solar irradiance over the past two millennia. Here, we analyse the significance of long-term trends from 1–1800 CE in the PAGES 2k compilation’s tree-ring, ice core, marine and lake sediment records and find, unlike ice-cores, glacier dynamics, marine and lake sediments, no suggestion of a pre-industrial cooling trend in the tree-ring records. To understand why the tree-ring proxies lack a significant pre-industrial cooling, we divide the dendro data by location (high NH latitudes vs. mid latitudes), seasonal response (annual vs. summer), detrending method, and temperature sensitivity (high vs. low). We conclude the ability to detect any pre-industrial, millennial-long cooling in the tree-ring proxies does not increase with latitude, seasonal sensitivity, or detrending method. Consequently, caution is advised when using multi-proxy approaches to reconstruct long-term temperature changes.

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Improved estimates of preindustrial biomass burning reduce the magnitude of aerosol climate forcing in the Southern Hemisphere

Science Advances ◽

10.1126/sciadv.abc1379 ◽

2021 ◽

Vol 7 (22) ◽

pp. eabc1379

Author(s):

Pengfei Liu ◽

Jed O. Kaplan ◽

Loretta J. Mickley ◽

Yang Li ◽

Nathan J. Chellman ◽

...

Keyword(s):

Southern Hemisphere ◽

Radiative Forcing ◽

Ice Core ◽

Ice Cores ◽

Terrestrial Ecosystems ◽

Rapid Expansion ◽

Past Century ◽

Fire Emissions ◽

The Past ◽

Fire Activity

Fire plays a pivotal role in shaping terrestrial ecosystems and the chemical composition of the atmosphere and thus influences Earth’s climate. The trend and magnitude of fire activity over the past few centuries are controversial, which hinders understanding of preindustrial to present-day aerosol radiative forcing. Here, we present evidence from records of 14 Antarctic ice cores and 1 central Andean ice core, suggesting that historical fire activity in the Southern Hemisphere (SH) exceeded present-day levels. To understand this observation, we use a global fire model to show that overall SH fire emissions could have declined by 30% over the 20th century, possibly because of the rapid expansion of land use for agriculture and animal production in middle to high latitudes. Radiative forcing calculations suggest that the decreasing trend in SH fire emissions over the past century largely compensates for the cooling effect of increasing aerosols from fossil fuel and biofuel sources.

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Ranges of moisture-source temperature estimated from Antarctic ice cores stable isotope records over glacial–interglacial cycles

Climate of the Past ◽

10.5194/cp-8-1109-2012 ◽

2012 ◽

Vol 8 (3) ◽

pp. 1109-1125 ◽

Cited By ~ 75

Author(s):

R. Uemura ◽

V. Masson-Delmotte ◽

J. Jouzel ◽

A. Landais ◽

H. Motoyama ◽

...

Keyword(s):

Air Temperature ◽

Ice Core ◽

Ice Cores ◽

Regression Equations ◽

Temperature Changes ◽

Source Temperature ◽

Moisture Source ◽

Isotopic Model ◽

Temperature Proxy ◽

Coefficient Of Regression

Abstract. A single isotope ratio (δD or δ18O) of water is widely used as an air-temperature proxy in Antarctic ice core records. These isotope ratios, however, do not solely depend on air-temperature but also on the extent of distillation of heavy isotopes out of atmospheric water vapor from an oceanic moisture source to a precipitation site. The temperature changes at the oceanic moisture source (Δ Tsource) and at the precipitation site (Δ Tsite) can be retrieved by using deuterium-excess (d) data. A new d record from Dome Fuji, Antarctica spanning the past 360 000 yr is presented and compared with records from Vostok and EPICA Dome C ice cores. In previous studies, to retrieve Δ Tsource and Δ Tsite information, different linear regression equations were proposed using theoretical isotope distillation models. A major source of uncertainty lies in the coefficient of regression, βsite which is related to the sensitivity of d to Δ Tsite. We show that different ranges of temperature and selections of isotopic model outputs may increase the value of βsite by more than a factor of two. To explore the impacts of this coefficient on reconstructed temperatures, we apply for the first time the exact same methodology to the isotope records from the three Antarctica ice cores. We show that uncertainties in the βsite coefficient strongly affect (i) the glacial–interglacial magnitude of Δ Tsource; (ii) the imprint of obliquity in Δ Tsource and in the site-source temperature gradient. By contrast, we highlight the robustness of Δ Tsite reconstruction using water isotopes records.

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Climate dependent contrast in surface mass balance in East Antarctica over the past 216 ka

Journal of Glaciology ◽

10.1017/jog.2016.85 ◽

2016 ◽

Vol 62 (236) ◽

pp. 1037-1048 ◽

Cited By ~ 4

Author(s):

F. PARRENIN ◽

S. FUJITA ◽

A. ABE-OUCHI ◽

K. KAWAMURA ◽

V. MASSON-DELMOTTE ◽

...

Keyword(s):

Mass Balance ◽

Ice Core ◽

Ice Cores ◽

East Antarctica ◽

Surface Mass Balance ◽

Last Interglacial ◽

Surface Mass ◽

The Past ◽

Water Stable Isotope ◽

Global Mean Sea Level

ABSTRACTDocumenting past changes in the East Antarctic surface mass balance is important to improve ice core chronologies and to constrain the ice-sheet contribution to global mean sea-level change. Here we reconstruct past changes in the ratio of surface mass balance (SMB ratio) between the EPICA Dome C (EDC) and Dome Fuji (DF) East Antarctica ice core sites, based on a precise volcanic synchronization of the two ice cores and on corrections for the vertical thinning of layers. During the past 216 000 a, this SMB ratio, denoted SMBEDC/SMBDF, varied between 0.7 and 1.1, being small during cold periods and large during warm periods. Our results therefore reveal larger amplitudes of changes in SMB at EDC compared with DF, consistent with previous results showing larger amplitudes of changes in water stable isotopes and estimated surface temperature at EDC compared with DF. Within the last glacial inception (Marine Isotope Stages, MIS-5c and MIS-5d), the SMB ratio deviates by up to 0.2 from what is expected based on differences in water stable isotope records. Moreover, the SMB ratio is constant throughout the late parts of the current and last interglacial periods, despite contrasting isotopic trends.

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On the relationship between stable isotopes and major impurity species as inferred from a two-dimensional firn sampling approach at EDML, East Antarctica

10.5194/egusphere-egu21-10362 ◽

2021 ◽

Author(s):

Thomas Münch ◽

Maria Hörhold ◽

Johannes Freitag ◽

Melanie Behrens ◽

Thomas Laepple

Keyword(s):

Isotopic Composition ◽

Interannual Variability ◽

Ice Core ◽

Ice Cores ◽

Temperature Changes ◽

Impurity Species ◽

Intermittent Precipitation ◽

Ice Core Record ◽

Stable Oxygen ◽

Atmospheric Variations

Ice cores constitute a major palaeoclimate archive by recording, among many others, the atmospheric variations of stable oxygen and hydrogen isotopic composition of water and of soluble ionic impurities. While impurities are used as proxies for, e.g., variations in sea ice, marine biological activity and volcanism, stable isotope records are the main source of information for the reconstruction of polar temperature changes.However, such reconstruction efforts are complicated by the fact that temperature is by far not the only driver of isotopic composition changes. A single isotopic ice-core record will comprise variations caused by a multitude of processes, from variable atmospheric circulation and moisture pathways to the intermittency of precipitation and finally to the mixing and re-location of surface snow by wind drift (stratigraphic noise). Under the assumption that specific trace components are originally deposited with the precipitated snow and its isotopic composition, the retrieved impurity records should display a similar spatial and seasonal to interannual variability as the isotope records, caused by local stratigraphic noise as well as the time-variable and intermittent precipitation patterns, respectively.In this contribution, we investigate the possible relationship between isotope and impurity data at the East Antarctic low-accumulation site EDML. We sampled and analysed isotopic composition and major impurity species on a four metre deep and 50&#160;metre long trench. This enables us (1) to study the spatial (horizontal times vertical) relationship in the data, and (2) to analyse and compare the seasonal and interannual variability after removing the strong contribution of local stratigraphic noise. By this, the study improves our understanding of the depositional mechanisms that play an important role for the formation of ice-core records, and it offers to investigate the potential of using impurities to correct isotopic variability in order to improve temperature reconstructions.

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Vostok, Antarctica, Ice Core: The Dust Record Over The Last Climatic Cycle (∼160 ka) (Abstract)

Annals of Glaciology ◽

10.3189/s0260305500006625 ◽

1988 ◽

Vol 11 ◽

pp. 204-204

Author(s):

L. Mounier ◽

J. R. Petit ◽

J. Jouzel ◽

C. Lorius ◽

Ye. S. Korotkevich ◽

...

Keyword(s):

Total Concentration ◽

Ice Core ◽

Ice Cores ◽

Optical Microscope ◽

Ice Age ◽

Maximum Temperature ◽

Temperature Changes ◽

Last Glacial ◽

Chemical Measurements ◽

The Last Glacial

The 2083 m Vostok Antarctic ice core provides a unique opportunity for access to many paleoclimatic and paleo-environmental proxy data. This core, which has been dated by using a glaciological model, fully covers the last glacial-interglacial cycle, and goes back to the ice age which preceded the last interglaciai (−160 ka B P ).A continuous deuterium record is now available and we have interpreted it in terms of local temperature changes. This record is dominated by the large 100 ka glacial-inter-glacial oscillation, with a maximum temperature amplitude of about 11°C; the long Last Glacial period is very well documented and it is confirmed that the warmest part of the Last Interglaciai period was about 2°C warmer than the Holocene. Comparison with the ice-volume marine record shows that the Vostok climate record is of relatively large geographical significance, which makes it possible to establish, over the last 160 ka, the link between worldwide climatic changes and the Vostok dust record that we present here.This dust content corresponds to the non-soluble microparticles. It was obtained on a discontinuous basis (1 sample = about ∼10 m). Due to the very low concentration of some samples (down to 20 x 10−9gg−1) and cracks in the ice from the first 1000 m depth, we used stringent decontamination procedures. Size distribution and total concentration were measured, using a Coulter counter and an optical microscope; the results were tested against chemical measurements (aluminium concentration). In previous studies, it has been shown that the main proportion of insoluble microparticles is of terrigenous origin and represents the small-sized (radius <2 μm) dust produced on the continents.The Vostok record displays an increase in dust concentration of up to 20 times during the coldest climatic periods, coupled with the presence of larger particles. It confirms, on a much longer time-scale, a characteristic previously noted in Antarctic and Greenland ice cores over the Last Glacial Maximum. This large increase is attributed to a greater areal extent of global tropical aridity during the cold periods, coupled with higher efficiency of atmospheric circulation in respect of dust production and transport. Beyond this, the relationship between the dust input and the successive stages during the Last Glacial is now very well documented and will be discussed with a view to correlating the Vostok climatic record with other marine and terrestrial paleodata.

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History of desert dust deposition recorded in the Elbrus ice core

10.5194/acp-2019-411 ◽

2019 ◽

Author(s):

Stanislav Kutuzov ◽

Michel Legrand ◽

Suzanne Preunkert ◽

Patrick Ginot ◽

Vladimir Mikhalenko ◽

...

Keyword(s):

North Africa ◽

Drought Index ◽

Decadal Variability ◽

Ice Core ◽

Ice Cores ◽

Dust Deposition ◽

The Past ◽

Dust Sources ◽

Increasing Trend ◽

History Of

Abstract. Ice cores are one of the most valuable paleo-archives. Records from the ice cores can provide information not only about the amount of dust in the atmosphere but also about dust sources and its changes in the past. A 182 m long ice core has been recovered at the western plateau of Mt. Elbrus (5115 m elevation) in 2009. This record was extended with the shallow ice core drilling in 2013. Here we present analysis of the concentrations of Ca2+, a commonly used proxy of dust, recorded in Elbrus ice core over the period 1774–2013. The calcium record reveals a quasi decadal variability with a general increasing trend. Using multiple regression analysis we found a statistically significant spatial correlation of the Elbrus Ca2+ summer concentrations and precipitation and soil moisture content in Levant region (specifically Syria and Iraq). The Ca2+ record also correlates with drought index in North Africa (r = 0.69 p

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What could have caused pre-industrial biomass burning emissions to exceed current rates?

Climate of the Past ◽

10.5194/cp-9-289-2013 ◽

2013 ◽

Vol 9 (1) ◽

pp. 289-306 ◽

Cited By ~ 39

Author(s):

G. R. van der Werf ◽

W. Peters ◽

T. T. van Leeuwen ◽

L. Giglio

Keyword(s):

Population Density ◽

Biomass Burning ◽

Transport Model ◽

Ice Core ◽

Ice Cores ◽

Fire Emissions ◽

Core Data ◽

Mixing Ratios ◽

The Past ◽

Co Concentrations

Abstract. Recent studies based on trace gas mixing ratios in ice cores and charcoal data indicate that biomass burning emissions over the past millennium exceeded contemporary emissions by up to a factor of 4 for certain time periods. This is surprising because various sources of biomass burning are linked with population density, which has increased over the past centuries. We have analysed how emissions from several landscape biomass burning sources could have fluctuated to yield emissions that are in correspondence with recent results based on ice core mixing ratios of carbon monoxide (CO) and its isotopic signature measured at South Pole station (SPO). Based on estimates of contemporary landscape fire emissions and the TM5 chemical transport model driven by present-day atmospheric transport and OH concentrations, we found that CO mixing ratios at SPO are more sensitive to emissions from South America and Australia than from Africa, and are relatively insensitive to emissions from the Northern Hemisphere. We then explored how various landscape biomass burning sources may have varied over the past centuries and what the resulting emissions and corresponding CO mixing ratio at SPO would be, using population density variations to reconstruct sources driven by humans (e.g., fuelwood burning) and a new model to relate savanna emissions to changes in fire return times. We found that to match the observed ice core CO data, all savannas in the Southern Hemisphere had to burn annually, or bi-annually in combination with deforestation and slash and burn agriculture exceeding current levels, despite much lower population densities and lack of machinery to aid the deforestation process. While possible, these scenarios are unlikely and in conflict with current literature. However, we do show the large potential for increased emissions from savannas in a pre-industrial world. This is mainly because in the past, fuel beds were probably less fragmented compared to the current situation; satellite data indicates that the majority of savannas have not burned in the past 10 yr, even in Africa, which is considered "the burning continent". Although we have not considered increased charcoal burning or changes in OH concentrations as potential causes for the elevated CO concentrations found at SPO, it is unlikely they can explain the large increase found in the CO concentrations in ice core data. Confirmation of the CO ice core data would therefore call for radical new thinking about causes of variable global fire rates over recent centuries.

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1000 year ice-core records from Berkner Island, Antarctica

Annals of Glaciology ◽

10.3189/172756402781817176 ◽

2002 ◽

Vol 35 ◽

pp. 45-51 ◽

Cited By ~ 39

Author(s):

Robert Mulvaney ◽

Hans Oerter ◽

David A. Peel ◽

Wolfgang Graf ◽

Carol Arrowsmith ◽

...

Keyword(s):

Decadal Variability ◽

Ice Core ◽

Ice Cores ◽

Aerosol Deposition ◽

Climate History ◽

Joint Project ◽

The Past ◽

Annual Layer ◽

History Of ◽

Field Season

AbstractTwo medium-depth ice cores were retrieved from Berkner Island by a joint project between the Alfred-Wegener-Institut and the British Antarctic Survey in the 1994/95 field season. A 151m deep core from the northern dome (Reinwarthhöhe) of Berkner Island spans 700 years, while a 181 m deep core from the southern dome (Thyssenhöhe) spans approximately 1200 years. Both cores display clear seasonal cycles in electrical conductivity measurements, allowing dating by annual-layer counting and the calculation of accumulation profiles. Stable-isotope measurements (both δ18O and δD), together with the accumulation data, allow us to estimate changes in climate for most of the past millennium: the data show multi-decadal variability around a generally stable long-termmean. In addition, a full suite of major chemistry measurements is available to define the history of aerosol deposition at these sites: again, there is little evidence that the chemistry of the sites has changed over the past six centuries. Finally, we suggest that the southern dome, with an ice thickness of 950 m, is an ideal site from which to gain a climate history of the late stages of the last glacial and the deglaciation for comparison with the records from the deep Antarctic ice cores, and with other intermediate-depth cores such as Taylor Dome and Siple Dome.

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