Variations in mineralogy of dust in an ice core obtained from northwestern Greenland over the past 100 years

Abstract. Our study is the first to demonstrate a high-temporal-resolution record of mineral composition in a Greenland ice core over the past 100 years. To reconstruct past variations in the sources and transportation processes of mineral dust in northwestern Greenland, we analysed the morphology and mineralogical composition of dust in the SIGMA-D ice core from 1915 to 2013 using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The results revealed that the ice core dust consisted mainly of silicate minerals and that the composition varied substantially on multi-decadal and inter-decadal scales, suggesting that the ice core minerals originated from different geological sources in different periods during the past 100 years. The multi-decadal variation trend differed among mineral types. Kaolinite, which generally formed in warm and humid climatic zones, was abundant in colder periods (1950–2004), whereas mica, chlorite, feldspars, mafic minerals, and quartz, which formed in arid, high-latitude, and local areas, were abundant in warmer periods (1915–1949 and 2005–2013). Comparison to Greenland surface temperature records indicates that multi-decadal variation in the relative abundance of these minerals was likely affected by local temperature changes in Greenland. Trajectory analysis shows that the minerals were transported mainly from the western coast of Greenland in the two warming periods, which was likely due to an increase in dust sourced from local ice-free areas as a result of shorter snow/ice cover duration in the Greenland coastal region during the melt season caused by recent warming. Meanwhile, ancient deposits in northern Canada, which were formed in past warmer climates, seem to be the best candidate during the colder period (1950–2004). Our results suggest that SEM–EDS analysis can detect variations in ice core dust sources during recent periods of low dust concentration.

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Variations in mineralogy of dust in an ice core obtained from northwestern Greenland over the past 100 years

10.5194/cp-2020-146 ◽

2020 ◽

Author(s):

Naoko Nagatsuka ◽

Kumiko Goto-Azuma ◽

Akane Tsushima ◽

Koji Fujita ◽

Sumito Matoba ◽

...

Keyword(s):

Ice Core ◽

Mineralogical Composition ◽

Middle Latitude ◽

High Temporal Resolution ◽

Western Coast ◽

Decadal Variation ◽

Temperature Changes ◽

The Past ◽

Middle Latitudes ◽

Geological Origin

Abstract. Our study is the first to demonstrate a high-temporal-resolution record of mineral composition in a Greenland ice core over the past 100 years. To reconstruct the past variations in the sources and transportation processes of mineral dust in northwestern Greenland, we analyzed the morphology and mineralogical composition of dust in an ice core from 1915 to 2013 using Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray Spectroscopy (EDS). Analysis of the SEM-EDS reveals that the ice core dust mainly consisted of silicate minerals and the composition varied substantially on multi-decadal and inter-decadal scales, suggesting that the geological origin of the ice core minerals changed periodically during the past 100 years. The multi-decadal variation trend differed among mineral types: kaolinite generally formed in low- or middle-latitude areas were abundant in the colder periods (1950 to 2000), whereas mica, chlorite, feldspars, mafic minerals, and quartzes formed in arid, high-latitude, and local areas were abundant in the warmer periods (1915 to 1949 and 2005 to 2013). This indicates that the multi-decadal variation of the relative abundance of the minerals can be attributed to the local temperature changes in Greenland. The trajectory analysis shows that the minerals were mainly transported from the western coast of Greenland in the two warming periods, which was likely due to an increase of dust sourced from local ice-free areas. On the other hand, the abundant kaolinite was likely derived from old sediments at higher latitudes in North America, rather than from low and middle latitudes.

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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

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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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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Wavelet analysis reveals periodic oscillations in a 1700 year ice-core record from Guliya, China

Annals of Glaciology ◽

10.3189/172756406781812375 ◽

2006 ◽

Vol 43 ◽

pp. 132-136 ◽

Cited By ~ 4

Author(s):

Meixue Yang ◽

Tandong Yao ◽

Xiaohua Gou ◽

Huijun Wang ◽

Thomas Neumann

Keyword(s):

Wavelet Analysis ◽

Ice Core ◽

Ice Cores ◽

Past Climate ◽

Ice Caps ◽

The Past ◽

Ice Cap ◽

Temperature And Precipitation ◽

Temperature Records ◽

Precipitation Records

AbstractIce cores contribute important records of past climate changes. As one of the thickest ice caps in central Asia, the Guliya ice cap (35°17′ N, 81°29′ E) provides valuable information for this critical region about the past climate and environment changes. We used wavelet analysis to examine periodic temperature and precipitation oscillations over the past 1700 years recorded in the Guliya ice core. The results show non-linear oscillations in the ice-core records, with multiple timescales. Temperature records indicate persistent oscillations with periodicities of approximately 200, 150 and 70 years. Precipitation records show significant periodicities at 200, 100, 150 and 60 years. However, the amplitude modulation and frequency vary with time. Wavelet analysis can explore these time series in greater detail and furnish additional useful information.

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Iron fluxes to Talos Dome, Antarctica, over the past 200 kyr

Climate of the Past ◽

10.5194/cp-9-597-2013 ◽

2013 ◽

Vol 9 (2) ◽

pp. 597-604 ◽

Cited By ~ 17

Author(s):

P. Vallelonga ◽

C. Barbante ◽

G. Cozzi ◽

J. Gabrieli ◽

S. Schüpbach ◽

...

Keyword(s):

Ross Sea ◽

Atmospheric Transport ◽

Ice Core ◽

Atmospheric Co2 ◽

Dust Deposition ◽

Transport Pathways ◽

The Past ◽

Dust Flux ◽

Dust Sources ◽

Ocean Sequestration

Abstract. Atmospheric fluxes of iron (Fe) over the past 200 kyr are reported for the coastal Antarctic Talos Dome ice core, based on acid leachable Fe concentrations. Fluxes of Fe to Talos Dome were consistently greater than those at Dome C, with the greatest difference observed during interglacial climates. We observe different Fe flux trends at Dome C and Talos Dome during the deglaciation and early Holocene, attributed to a combination of deglacial activation of dust sources local to Talos Dome and the reorganisation of atmospheric transport pathways with the retreat of the Ross Sea ice shelf. This supports similar findings based on dust particle sizes and fluxes and Rare Earth Element fluxes. We show that Ca and Fe should not be used as quantitative proxies for mineral dust, as they all demonstrate different deglacial trends at Talos Dome and Dome C. Considering that a 20 ppmv decrease in atmospheric CO2 at the coldest part of the last glacial maximum occurs contemporaneously with the period of greatest Fe and dust flux to Antarctica, we confirm that the maximum contribution of aeolian dust deposition to Southern Ocean sequestration of atmospheric CO2 is approximately 20 ppmv.

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Iron fluxes to Talos Dome, Antarctica, over the past 200 kyr

Climate of the Past Discussions ◽

10.5194/cpd-8-6093-2012 ◽

2012 ◽

Vol 8 (6) ◽

pp. 6093-6110

Author(s):

P. Vallelonga ◽

C. Barbante ◽

G. Cozzi ◽

J. Gabrieli ◽

S. Schüpbach ◽

...

Keyword(s):

Ross Sea ◽

Atmospheric Transport ◽

Ice Core ◽

Atmospheric Co2 ◽

Dust Deposition ◽

Transport Pathways ◽

The Past ◽

Dust Flux ◽

Dust Sources ◽

Ocean Sequestration

Abstract. Atmospheric fluxes of iron (Fe) over the past 200 kyr are reported for the coastal Antarctic Talos Dome ice core, based on acid leachable Fe concentrations. Fluxes of Fe to Talos Dome were consistently greater than those at Dome C, with the greatest difference observed during interglacial climates. We observe different Fe flux trends at Dome C and Talos Dome during the deglaciation and early Holocene, attributed to a combination of deglacial activation of dust sources local to Talos Dome and reorganization of atmospheric transport pathways with the retreat of the Ross Sea ice shelf. This supports similar findings based on dust particle sizes and fluxes and Rare Earth Element fluxes. We show that Ca and Fe should not be used as quantitative proxies for mineral dust, as they all demonstrate different deglacial trends at Talos Dome and Dome C. Considering that a 20 ppmv decrease in atmospheric CO2 at the coldest part of the last glacial maximum occurs contemporaneously with the period of greatest Fe and dust flux to Antarctica, we conclude that the maximum contribution of aeolian dust deposition to Southern Ocean sequestration of atmospheric CO2 is approximately 20 ppmv.

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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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Holocene temperature variations inferred from Antarctic ice cores

Annals of Glaciology ◽

10.3189/1994aog20-1-427-436 ◽

1994 ◽

Vol 20 ◽

pp. 427-436 ◽

Cited By ~ 6

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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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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