scholarly journals Variability of sulfate signal in ice core records based on five replicate cores

2016 ◽  
Vol 12 (1) ◽  
pp. 103-113 ◽  
Author(s):  
E. Gautier ◽  
J. Savarino ◽  
J. Erbland ◽  
A. Lanciki ◽  
P. Possenti
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Flux Measurement ◽  
Volcanic Eruptions ◽  
Local Scale ◽  
High Temporal Resolution ◽  
Polar Regions ◽  
Regional Patterns ◽  
Snow Drift ◽  
Volcanic Events

Abstract. Current volcanic reconstructions based on ice core analysis have significantly improved over the past few decades by incorporating multiple-core analyses with a high temporal resolution from different parts of the polar regions into a composite common volcanic eruption record. Regional patterns of volcanic deposition are based on composite records, built from cores taken at both poles. However, in many cases only a single record at a given site is used for these reconstructions. This assumes that transport and regional meteorological patterns are the only source of the dispersion of the volcanic products. Here we evaluate the local-scale variability of a sulfate profile in a low-accumulation site (Dome C, Antarctica), in order to assess the representativeness of one core for such a reconstruction. We evaluate the variability with depth, statistical occurrence, and sulfate flux deposition variability of volcanic eruptions detected in five ice cores, drilled 1 m apart from each other. Local-scale variability, essentially attributed to snow drift and surface roughness at Dome C, can lead to a non-exhaustive record of volcanic events when a single core is used as the site reference, with a bulk probability of 30 % of missing volcanic events and close to 65 % uncertainty on one volcanic flux measurement (based on the standard deviation obtained from a five-core comparison). Averaging n records reduces the uncertainty of the deposited flux mean significantly (by a factor 1∕ √ n); in the case of five cores, the uncertainty of the mean flux can therefore be reduced to 29 %.

scholarly journals Variability of sulfate signal in ice-core records based on five replicate cores

2015 ◽  
Vol 11 (4) ◽  
pp. 3973-4002 ◽  
Author(s):  
E. Gautier ◽  
J. Savarino ◽  
J. Erbland ◽  
A. Lanciki ◽  
P. Possenti
Keyword(s):  
Ice Core ◽  
Ice Cores ◽  
Volcanic Eruptions ◽  
Local Scale ◽  
High Temporal Resolution ◽  
Deposition Flux ◽  
Polar Regions ◽  
Regional Patterns ◽  
Snow Drift ◽  
Volcanic Events

Abstract. Current volcanic reconstructions based on ice core analysis have significantly improved over the last decades. Relying on limited and disparate sulfate profiles at first, they have progressively incorporated multi cores analysis with high temporal resolution from different parts of the Polar Regions. Regional patterns of volcanic deposition flux are now based on composite records, built from several cores taken at both poles. However, it is worth mentioning that most of the time only a single record at a given site is used for such reconstructions. This implicitly assumes that transport and regional meteorological patterns are the only source of the dispersion of the volcanic-products. In the present work, we evaluate the local scale variability of a sulfate profile in a low accumulation site (Dome C, Antarctica), in order to assess the representativeness of one core for such reconstruction. We evaluate the depth variability, statistical occurrence, and sulfate flux deposition variability of volcanic eruptions detected on 5 ice cores, drilled 1 m away from each other. Local scale variability, essentially attributed to snow drift and surface roughness at Dome C, can lead to a non-exhaustive record of volcanic events when a single core is used as the site reference with a bulk probability of 30 % of missing volcanic events and 60 % uncertainty on the volcanic flux estimation. Averaging multiple records almost erases the probability of missing volcanic events and can reduce by half the uncertainty pertaining to the deposition flux.

Tephra in the Greenland Ice cores: Insights into Icelandic volcano-climate impacts

2021 ◽  
Author(s):  
Imogen Gabriel ◽  
Gill Plunkett ◽  
Peter Abbott ◽  
Bergrún Óladóttir ◽  
Joseph McConnell ◽  
...  
Keyword(s):  
High Resolution ◽  
Ice Core ◽  
Ice Cores ◽  
Volcanic Eruptions ◽  
Climate Impacts ◽  
Geochemical Analysis ◽  
Volcanic Events ◽  
Societal Impacts ◽  
The Impact ◽  
Ice Core Records

<p>Volcanic eruptions are considered as one of the primary natural drivers for changes in the global climate system and understanding the impact of past eruptions on the climate is integral to adopt appropriate responses towards future volcanic eruptions.</p><p>The Greenland ice core records are dominated by Icelandic eruptions, with several volcanic systems (Katla, Hekla, Bárðarbunga-Veiðivötn and Grimsvötn) being highly active throughout the Holocene. A notable period of increased Icelandic volcanic activity occurred between 500-1250 AD and coincided with climatic changes in the North Atlantic region which may have facilitated the Viking settlement of Greenland and Iceland. However, a number of these volcanic events are poorly constrained (duration and magnitude). Consequently, the Greenland ice cores offer the opportunity to reliably reconstruct past Icelandic volcanism (duration, magnitude and frequency) due to their high-resolution, the proximity of Iceland to Greenland and subsequent increased likelihood of volcanic fallout deposits (tephra particles and sulphur aerosols) being preserved. However, both the high frequency of eruptions between 500-1250 AD and the geochemical similarity of Iceland’s volcanic centres present challenges in making the required robust geochemical correlations between the source volcano and the ice core records and ultimately reliably assessing the climatic-societal impacts of these eruptions.</p><p>To address this, we use two Greenland ice core records (TUNU2013 and B19) and undertake geochemical analysis on tephra from the volcanic events in the selected time window which have been detected and sampled using novel techniques (insoluble particle peaks and sulphur acidity peaks). Further geochemical analysis of proximal material enables robust correlations to be made between the events in the ice core records and their volcanic centres. The high-resolution of these polar archives provides a precise age for the event and when utilised alongside other proxies (i.e. sulphur aerosols), both the duration and magnitude of these eruptions can be constrained, and the climatic-societal impacts of these eruptions reliably assessed.</p>

scholarly journals A 200 year sub-annual record of sulfate in West Antarctica, from 16 ice cores

2004 ◽  
Vol 39 ◽  
pp. 545-556 ◽  
Author(s):  
Daniel Dixon ◽  
Paul A. Mayewski ◽  
Susan Kaspari ◽  
Sharon Sneed ◽  
Mike Handley
Keyword(s):  
Ice Core ◽  
Temporal Distribution ◽  
Ice Cores ◽  
Volcanic Eruptions ◽  
Global Scale ◽  
West Antarctica ◽  
West Antarctic ◽  
Volcanic Events ◽  
Climate Transition ◽  
Better Than

AbstractSixteen high-resolution ice-core records from West Antarctica and South Pole are used to examine the spatial and temporal distribution of sulfate for the last 200 years. The preservation of seasonal layers throughout the length of each record results in a dating accuracy of better than 1 year based on known global-scale volcanic events. A dual transport source for West Antarctic sea-salt (ss) SO42– and excess (xs) SO42– is observed: lower-tropospheric for areas below 1000m elevation and mid-/upper-tropospheric/stratospheric for areas located above 1000 m. Our xsSO42– records with volcanic peaks removed do not display any evidence of an anthropogenic impact on West Antarctic SO42– concentrations but do reveal that a major climate transition takes place over West Antarctica at ∼1940. Global-scale volcanic eruptions appear as significant peaks in the robust-spline residual xsSO42– records from sites located above 1000m elevation but do not appear in the residual records from sites located below 1000 m.

scholarly journals Technical details concerning development of a 1200 yr proxy index for global volcanism

2013 ◽  
Vol 5 (1) ◽  
pp. 187-197 ◽  
Author(s):  
T. J. Crowley ◽  
M. B. Unterman
Keyword(s):  
Climate Models ◽  
Ice Core ◽  
Growth Curves ◽  
Ice Cores ◽  
Simultaneous Occurrence ◽  
High Temporal Resolution ◽  
Polar Regions ◽  
Effective Particle ◽  
Global Volcanism ◽  
Technical Details

Abstract. This report describes details of developing a volcano forcing reconstruction (Crowley et al., 2008) for climate models that is based primarily on sulphate records in Antarctic and Greenland ice cores. The chronology of eruptions is considered accurate to within 1 yr for the interval AD 1104–2000 and about 2 yr for AD 800–1103. The reconstruction involves (1) calibration against satellite aerosol optical depth (AOD) estimates of the 1991 Pinatubo/Hudson eruptions; (2) partial validation against independent lunar estimates of AOD and global sulphate emissions; (3) partial assessment of uncertainties in AOD estimates; (4) assessment of possible tropical "false positives" in ice core reconstructions due to simultaneous occurrence of mid/high-latitude eruptions in each hemisphere; (5) identification of a new category of eruptions, termed "unipolar" tropical eruptions, in which the eruption plume penetrates mainly to polar regions in only the hemisphere of its eruption; (6) use of different growth curves for high- and low-latitude eruptions; (7) specification of 2/3 power shortwave scaling for eruptions larger than the 1991 Pinatubo eruption; (8) introduction of an estimate of effective particle size that affects lifetime and scattering properties of stratospheric aerosols; and (9) utilization of bimonthly-resolution electrical conductivity measurements to estimate the eruption date of the 1258/1259 eruption as 1257.7±0.2. The data, and a high-temporal resolution reconstruction for climate models, are available at: http://hurricane.ncdc.noaa.gov/pls/paleox/f?p=519:1:::::P1_STUDY_ID:14168.

scholarly journals An independently dated 2000-yr volcanic record from Law Dome, East Antarctica, including a new perspective on the dating of the 1450s CE eruption of Kuwae, Vanuatu

2012 ◽  
Vol 8 (6) ◽  
pp. 1929-1940 ◽  
Author(s):  
C. T. Plummer ◽  
M. A. J. Curran ◽  
T D. van Ommen ◽  
S. O. Rasmussen ◽  
A. D. Moy ◽  
...  
Keyword(s):  
Climate Models ◽  
Ice Core ◽  
Ice Cores ◽  
Volcanic Eruptions ◽  
East Antarctica ◽  
External Information ◽  
Climatic Effects ◽  
High Accumulation ◽  
Annual Layer ◽  
Volcanic Events

Abstract. Volcanic eruptions are an important cause of natural climate variability. In order to improve the accuracy of climate models, precise dating and magnitude of the climatic effects of past volcanism are necessary. Here we present a 2000-yr record of Southern Hemisphere volcanism recorded in ice cores from the high accumulation Law Dome site, East Antarctica. The ice cores were analysed for a suite of chemistry signals and are independently dated via annual layer counting, with 11 ambiguous years at 23 BCE, which has presently the lowest error of all published long Antarctic ice cores. Independently dated records are important to avoid circular dating where volcanic signatures are assigned a date from some external information rather than using the date it is found in the ice core. Forty-five volcanic events have been identified using the sulphate chemistry of the Law Dome record. The low dating error and comparison with the NGRIP (North Greenland Ice Core Project) volcanic records (on the GICC05 timescale) suggest Law Dome is the most accurately dated Antarctic volcanic dataset, which will improve the dating of individual volcanic events and potentially allow better correlation between ice core records, leading to improvements in global volcanic forcing datasets. One of the most important volcanic events of the last two millennia is the large 1450s CE event, usually assigned to the eruption of Kuwae, Vanuatu. In this study, we review the evidence surrounding the presently accepted date for this event, and make the case that two separate eruptions have caused confusion in the assignment of this event. Volcanic sulphate deposition estimates are important for modelling the climatic response to eruptions. The largest volcanic sulphate events in our record are dated at 1458 CE (Kuwae?, Vanuatu), 1257 and 422 CE (unidentified).

scholarly journals A new continuous high-resolution detection system for sulphate in ice cores

2007 ◽  
Vol 45 ◽  
pp. 178-182 ◽  
Author(s):  
Matthias Bigler ◽  
Anders Svensson ◽  
Jørgen Peder Steffensen ◽  
Patrik Kaufmann
Keyword(s):  
Detection System ◽  
Ice Core ◽  
Flow Analysis ◽  
Ice Cores ◽  
Volcanic Eruptions ◽  
Barium Sulphate ◽  
High Temporal Resolution ◽  
Continuous Flow Analysis ◽  
Explosive Volcanic Eruptions ◽  
Analysis System

AbstractSulphate (SO42–) is a major ion found in polar ice cores and is related to different aerosol sources and processes. Explosive volcanic eruptions, even far away, can cause distinct sulphate peaks in ice core records. Thus, a robust sulphate detection system which is suitable for fieldwork and which enables the measurement of sulphate at high temporal resolution is of great interest. In this study, we present the adaptation of a new continuous flow analysis system for sulphate that is based on a spectrophotometric method using dimethylsulfonazo III and an inline reactor column containing barium sulphate particles. The method shows a detection limit of ∽70 ng g–1 and a linear range up to at least 3000 ng g–1. It is simple, robust and less prone to interferences compared to the previously used method.

scholarly journals An independently dated 2000-yr volcanic record from Law Dome, East Antarctica, including a new perspective on the dating of the c. 1450s eruption of Kuwae, Vanuatu

2012 ◽  
Vol 8 (3) ◽  
pp. 1567-1590 ◽  
Author(s):  
C. T. Plummer ◽  
M. A. J. Curran ◽  
T. D. van Ommen ◽  
S. O. Rasmussen ◽  
A. D. Moy ◽  
...  
Keyword(s):  
Climate Models ◽  
Ice Core ◽  
Ice Cores ◽  
Volcanic Eruptions ◽  
East Antarctica ◽  
External Information ◽  
Time Interval ◽  
Climatic Effects ◽  
High Accumulation ◽  
Volcanic Events

Abstract. Volcanic eruptions are an important cause of natural climate variability. In order to improve the accuracy of climate models, precise dating and magnitude of the climatic effects of past volcanism are necessary. Here we present a 2000-yr record of Southern Hemisphere volcanism recorded in ice cores from the high accumulation Law Dome site, East Antarctica. The ice cores were analyzed for a suite of chemistry signals and are independently dated via annual layer counting, with 11 ambiguous years by the end of the record. Independently dated records are important to avoid circular dating where volcanic signatures are assigned a date from some external information rather than using the date it is found in the ice core. Forty-five volcanic events have been identified using the sulfate chemistry of the Law Dome record. Comparisons between Law Dome and NGRIP (Greenland) volcanic records suggest Law Dome is the most accurately dated Antarctic volcanic dataset and allows for the records to be synchronized with NGRIP, leading to an improved global volcanic forcing dataset. Volcanic sulfate deposition estimates are important for modeling the climatic response to eruptions. The largest volcanic sulfate events in our record are dated at 1458 CE (Kuwae, Vanuatu), 1257 and 423 CE (unidentified). Using our record we refine the dating of previously known volcanic events and present evidence for two separate eruptions during the period 1450–1460 CE, potentially causing confusion in the assignment of the Kuwae (Vanuatu) eruption to volcanic signatures during this time interval.

scholarly journals Glaciological Investigations of the Tropical Quelccaya Ice Cap, Peru

1980 ◽  
Vol 25 (91) ◽  
pp. 69-84 ◽  
Author(s):  
Lonnie G. Thompson
Keyword(s):  
Rainy Season ◽  
Ice Core ◽  
Ice Cores ◽  
Dry Season ◽  
Radioactive Material ◽  
Polar Regions ◽  
Near Surface ◽  
Ice Cap ◽  
Activity Measurements ◽  
Quelccaya Ice Cap

AbstractGlaciological results of the continuing investigations of the Quelccaya ice cap located at lat. 13° 56’ S., long. 70° 50’ W., in the Cordillera Oriental of southern Peru are presented. Ice cores to a depth of 15 m have been retrieved from the summit dome (5650 m), middle dome (5543 m), and south dome (5480 m) and sampled in detail for microparticle, oxygen-isotope, and total-β-activity measurements. Results of these core analyses indicate that although the summit of this ice cap is only 300 m above the annual snow line and the firn is temperate, an interpretable stratigraphic record is preserved. The marked seasonal ice stratigraphy is produced by the marked seasonal variation in regional precipitation. High concentrations of microparticles and β- radioactive material occur during the dry season (May-August). Microparticles deposited during the rainy season are larger than those deposited during the dry season. On the Quelccaya ice cap the most negative δ18O values occur during the warmer rainy season (the opposite occurs in polar regions). The near-surface mean δ value of – 21‰ is remarkably low for this tropical site where the measured mean annual air temperature is – 3°C The seasonality of the microparticles, total β activity, and isotope ratios offers the prospect of a climatic ice-core record from this tropical ice cap.

First continuous high-resolution aerosol record from the East Greenland Ice Core Project (EGRIP), covering the last 15,000 years

2020 ◽  
Author(s):  
Camilla Marie Jensen ◽  
Tobias Erhardt ◽  
Giulia Sinnl ◽  
Hubertus Fischer
Keyword(s):  
High Resolution ◽  
Biomass Burning ◽  
Forest Fires ◽  
Ice Core ◽  
Greenland Ice Sheet ◽  
Ice Cores ◽  
Background Level ◽  
Volcanic Eruptions ◽  
Atmospheric Conditions ◽  
Data Set

<p>Ice sheets are reliable archives of atmospheric impurities such as aerosols and gasses of both natural and anthropogenic origin. Impurity records from Greenland ice cores reveal much information about previous atmospheric conditions and long-range transport in the Northern hemisphere going back more than a hundred thousand years.</p><p>Here we present the data from the upper 1,411 m from the EGRIP ice core, measuring conductivity, dust, sodium, calcium, ammonium, and nitrate. These records contain information about ocean sources, transport of terrestrial dust, soil and vegetation emissions as well as biomass burning, volcanic eruptions, etc., covering approximately the past 15,000 years. This newly obtained data set is unique as it provides the first high-resolution information about several thousands of years of the mid-Holocene period in Greenland that none of the previous impurity records from the other deep Greenland ice cores had managed to cover before due to brittle ice. This will contribute to further understanding of the atmospheric conditions for the pre-industrial period.</p><p>The ammonium record contains peaks significantly higher than the background level. These peaks are caused by biomass burning or forest fires emitting plumes of ammonia large enough so that they can extend to the free troposphere and be efficiently transported all the way to the Greenland ice sheet. Here we present preliminary results of the wild fire frequency covering the entire Holocene, where the wild fires are defined as outliers in the ammonium record of annual means.</p>

scholarly journals Inferring paleo-accumulation records from ice-core data by an adjoint method: application to James Ross Island's ice core

2014 ◽  
Vol 10 (5) ◽  
pp. 3821-3845 ◽  
Author(s):  
C. Martín ◽  
R. Mulvaney ◽  
G. H. Gudmundsson ◽  
H. Corr
Keyword(s):  
Vertical Velocity ◽  
Adjoint Method ◽  
Ice Core ◽  
Synthetic Data ◽  
Ice Cores ◽  
Snow Accumulation ◽  
Polar Regions ◽  
History Of ◽  
Climatic Record ◽  
Accumulation History

Abstract. Ice cores contain a record of snow precipitation that includes information about past atmospheric circulation and mass imbalance in the polar regions. We present a novel adjoint method to reconstruct a climatic record by both optimally dating an ice-core and deriving from it a detailed accumulation history. The motivation of our work is the recent application of phase sensitive radar which measures the vertical velocity of an ice column. The velocity is dependent on the history of subsequent snow accumulation, compaction and compression; and in our inverse formulation of this problem, measured vertical velocity profiles can be utilized directly thereby reducing the uncertainty introduced by ice flow modelling. We first apply our method to synthetic data in order to study its capability and the effect of noise and gaps in the data on retrieved accumulation history. The method is then applied to the ice core retrieved from James Ross Island, Antarctica. We show that the method is robust and that the results depend on quality of the age-depth observations and the derived flow regime around the core site. The method facilitates the incorporation of increasing detail provided by ice-core analysis together with observed full-depth velocity in order to construct a complete climatic record of the polar regions.

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