Comparison of 14C Ages Between LSC and AMS Measurements of Choukai Jindai Cedar Tree Rings at 2600 cal BP

Radiocarbon ages of Choukai Jindai cedar tree rings growing in the excess era of 14C concentrations during 2757–2437 cal BP were measured using 2 types of 14C measurement methods, i.e. liquid scintillation counting (LSC) and accelerator mass spectrometry (AMS). The difference between the 2 methods is 3.7 ± 5.2 14C yr on average for 61 single-year tree rings, indicating good agreement between the methods. The Choukai data sets show a small sharp bump with an average 14C age of 2497.1 ± 3.0 14C yr BP during 2650–2600 cal BP. Although the profile of the Choukai LSC data set compares well with that of IntCal04, having a 14C age difference of 4.6 ± 5.3 14C yr on average, the Choukai LSC 14C ages indicate variability against the smoothed profile of IntCal04.

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The Brazilian AMS Radiocarbon Laboratory (LAC-UFF) and the Intercomparison of Results with CENA and UGAMS

Radiocarbon ◽

10.1017/s003382220005743x ◽

2013 ◽

Vol 55 (2) ◽

pp. 325-330 ◽

Cited By ~ 30

Author(s):

K D Macario ◽

P R S Gomes ◽

R M Anjos ◽

C Carvalho ◽

R Linares ◽

...

Keyword(s):

Mass Spectrometry ◽

Latin America ◽

Liquid Scintillation Counting ◽

Nuclear Energy ◽

Liquid Scintillation ◽

Scintillation Counting ◽

Physics Institute ◽

University Of Georgia ◽

The University ◽

Good Agreement

After 22 yr of the low-level liquid scintillation counting 14C laboratory at the Center for Nuclear Energy in Agriculture (CENA) at São Paulo University (USP), Piracicaba, Brazil, and several collaborative projects with Brazilian and international researchers from distinct scientific areas, the first 14C accelerator mass spectrometry (AMS) laboratory in Latin America was installed at the Physics Institute of the Universidade Federal Fluminense (UFF), Niterói, Brazil. A 250kV single stage accelerator produced by National Electrostatics Corporation began its operation in 2012. In this work, we compare measurements performed at the AMS Radiocarbon Laboratory at UFF (LAC-UFF) with those performed at CENA and the University of Georgia (UGAMS), Georgia, USA. All the results obtained from distinct inorganic and organic samples were in very good agreement.

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14C Dating of ∼2500-Yr-Old Choukai Jindai Cedar Tree Rings from Japan Using Highly Accurate LSC Measurement

Radiocarbon ◽

10.1017/s0033822200038832 ◽

2006 ◽

Vol 48 (3) ◽

pp. 401-408 ◽

Cited By ~ 10

Author(s):

Hirohisa Sakurai ◽

Wataru Kato ◽

Yosuke Takahashi ◽

Kayo Suzuki ◽

Yui Takahashi ◽

...

Keyword(s):

Tree Rings ◽

Liquid Scintillation ◽

Far East ◽

Outer Edge ◽

Data Sets ◽

Calibration Data ◽

Cellulose Sample ◽

14C Dating ◽

Data Set ◽

The Far East

Radiocarbon ages of 8 decadal tree rings and 66 single-yr tree rings have been measured with a highly accurate liquid scintillation counting (LSC) system (0.2% error) after synthesizing 10.5 g of benzene for each α-cellulose sample produced from tree rings of Choukai Jindai cedar in Japan (39°N). The 14C ages were between 2449 and 2539 14C yr BP for the 21 samples. From the wiggle-matching of the data set using the IntCal04 (Reimer et al. 2004) calibration data in OxCal v 3.10 (Bronk Ramsey 2005), the estimated age of the outer edge of the Choukai tree rings was 477.5 BC (±12.5 yr) with a confidence level of 95.5%; hence, the Choukai tree rings range from 2757 to 2437 cal BP. The age indicates an improved eruption date of the Choukai Volcano. The statistical errors at 1 σ are approximately ± 10 and ± 7 14C yr for the 5-yr data and the decadal data from the single-yr measurements, respectively. For the interval between 2580 and 2520 cal BP, it is statistically significant that the Choukai 14C ages are ∼16 14C yr older on average than both the IntCal04 and QL German oak (∼50°N) data sets. The ∼2.0% offset is informative for the study of regional offset in the Far East.

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14C Age Measurements of Single-Year Tree Rings of Old Wood Samples 22,000 14C Years BP

Radiocarbon ◽

10.1017/s0033822200045999 ◽

2010 ◽

Vol 52 (3) ◽

pp. 901-906 ◽

Cited By ~ 1

Author(s):

Taiichi Sato ◽

Hirohisa Sakurai ◽

Kayo Suzuki ◽

Yui Takahashi

Keyword(s):

Mass Spectrometry ◽

Tree Rings ◽

Periodic Variation ◽

Data Sets ◽

Weighted Mean ◽

Data Set ◽

Mean Values ◽

14C Age ◽

Combined Data ◽

Sequential Measurements

Radiocarbon ages of single-year tree rings were measured for Kaminoyama wood samples using accelerator mass spectrometry (AMS) in 2 Japanese facilities, MALT and JAEA, in order to investigate the periodic variation of 14C concentrations relating to the 11-yr solar cycle near 26,000 yr BP. Eight sequential measurements of 14C ages were carried out for a set of 13 alternate single-year tree rings covering 26 yr. Averages of the 5 data sets in MALT and 3 data sets in JAEA were 22,146 ± 50 and 22,407 ± 58 14C yr BP, respectively, indicating an offset of 260 ± 77 14C yr. Multiple sequential measurements are advantageous for evaluating offsets. The standard deviation of the residuals of 14C ages from the averages in each data set was 118 14C yr, in contrast to that of 234 14C yr for the combined data sets due to an elimination effect in the offsets. The profiles of weighted mean values for the residuals of 14C ages showed similar enhancements with a width of ∼12 yr for measurements in the 2 facilities. This indicates the reproducibility of the multiple sequential measurements. In the profile for the combined 8 data sets, the 14C enhancement was 73 ± 36 14C yr from the average.

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Precise Comparison of 14C Ages from Choukai Jindai Cedar with IntCal04 Raw Data

Radiocarbon ◽

10.1017/s0033822200056332 ◽

2010 ◽

Vol 52 (4) ◽

pp. 1599-1609 ◽

Cited By ~ 10

Author(s):

Kayo Suzuki ◽

Hirohisa Sakurai ◽

Yui Takahashi ◽

Taiichi Sato ◽

Shuichi Gunji ◽

...

Keyword(s):

Mass Spectrometry ◽

Tree Rings ◽

Accelerator Mass Spectrometry ◽

Correlation Coefficients ◽

Data Sets ◽

Calibration Data ◽

Data Set ◽

Raw Data ◽

Temporal Profile ◽

Temporal Profiles

We measured the radiocarbon ages of 165 single-year tree rings from a Japanese Choukai Jindai cedar using accelerator mass spectrometry (AMS). By wiggle-matching the Choukai_AMS data set to the IntCal04 calibration data using OxCal v 3.10 and using the variation of the correlation coefficients between the Choukai_AMS and IntCal04 data sets, we precisely re-estimated that the 321 Choukai Jindai cedar tree rings range from 780 to 460 cal BC with an accuracy of 8 yr. The Choukai_AMS data set is older than the 3 raw data sets of European tree rings that comprise IntCal04. The Belfast and Seattle data sets are younger by −21.3 ± 5.5 and −22.7 ± 5.6 14C yr, respectively. The Choukai Jindai cedar is ∼22 14C yr older than the European tree rings, which is equivalent to an offset of −2.8‰ in 14C. In addition, the Choukai_AMS data set correlates well with the Belfast and Seattle data sets, with correlation coefficients of 0.89 and 0.68, respectively, between the temporal profiles. Hence, the temporal profile of the Choukai 14C ages shows a global variation.

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A Ccomparison of sedigraph and pipette methods for soil particle-size analysis

Soil Research ◽

10.1071/sr9930407 ◽

1993 ◽

Vol 31 (4) ◽

pp. 407 ◽

Cited By ~ 22

Author(s):

GD Buchan ◽

KS Grewal ◽

JJ Claydon ◽

RJ Mcpherson

Keyword(s):

Particle Size ◽

New Zealand ◽

Particle Size Analysis ◽

Size Analysis ◽

Data Sets ◽

Regression Equations ◽

Total Iron Content ◽

Data Set ◽

X Ray ◽

The Difference

The X-ray attenuation (Sedigraph) method for particle-size analysis is known to consistently estimate a finer size distribution than the pipette method. The objectives of this study were to compare the two methods, and to explore the reasons for their divergence. The methods are compared using two data sets from measurements made independently in two New Zealand laboratories, on two different sets of New Zealand soils, covering a range of textures and parent materials. The Sedigraph method gave systematically greater mass percentages at the four measurement diameters (20, 10, 5 and 2 �m). For one data set, the difference between clay (<2 �m) percentages from the two methods is shown to be positively correlated (R2 = 0.625) with total iron content of the sample, for all but one of the soils. This supports a novel hypothesis that the typically greater concentration of Fe (a strong X-ray absorber) in smaller size fractions is the major factor causing the difference. Regression equations are presented for converting the Sedigraph data to their pipette equivalents.

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A Review of the Radiocarbon Dates for the Afanasyevo Culture (Central Asia): Shifting Towards the “Shorter” Chronology

Radiocarbon ◽

10.1017/rdc.2018.70 ◽

2018 ◽

Vol 61 (1) ◽

pp. 243-263 ◽

Cited By ~ 3

Author(s):

Andrey V Poliakov ◽

Svetlana V Svyatko ◽

Nadezhda F Stepanova

Keyword(s):

Mass Spectrometry ◽

Accelerator Mass Spectrometry ◽

Liquid Scintillation Counting ◽

Liquid Scintillation ◽

Scintillation Counting ◽

Radiocarbon Dates ◽

Archaeological Data ◽

Depth Analysis ◽

Over Time ◽

Ams Dates

ABSTRACTThis article provides a summary and in-depth analysis of all existing radiocarbon (14C) dates for the Afanasyevo Culture of the Paleometal period. The previous “long” chronology of the culture was widely criticized and contradicted many archaeological observations. The exceedingly wide ranges of the liquid scintillation counting (LSC) dates from bone samples produced in several laboratories and the systematically older ages for the wood/charcoal samples finally reveal the shortcomings of the conventional “long” chronology. From accelerator mass spectrometry (AMS), the Afanasyevo burials of the Altai are dated to the 31st–29th century BC, whereas those of the Middle Yenisei Region to the 29th–25th century BC, which confirms the relatively earlier age of the Altai monuments. The “short” chronology removes the incompatibility of deriving the Afanasyevo Culture from the Yamnaya Culture, which previously appeared “younger” than the Afanasyevo, and also contradictions with the archaeological data. It also explains the small number of sites, the small size of the cemeteries and the lack of the internal periodization. We can now clearly move, from the earlier understanding that the Afanasyevo chronology is too broad, towards a different perception. The new AMS dates only represent a “core” for the Afanasyevo chronology, which cannot be narrowed down, but could be slightly expanded over time.

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Two decades of satellite observations of AOD over mainland China using ATSR-2, AATSR and MODIS/Terra: data set evaluation and large-scale patterns

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-1573-2018 ◽

2018 ◽

Vol 18 (3) ◽

pp. 1573-1592 ◽

Cited By ~ 48

Author(s):

Gerrit de Leeuw ◽

Larisa Sogacheva ◽

Edith Rodriguez ◽

Konstantinos Kourtidis ◽

Aristeidis K. Georgoulias ◽

...

Keyword(s):

Time Series ◽

European Space Agency ◽

Mainland China ◽

Satellite Observations ◽

Data Sets ◽

Data Set ◽

Modis Aod ◽

The Difference ◽

Along Track ◽

Aerosol Properties

Abstract. The retrieval of aerosol properties from satellite observations provides their spatial distribution over a wide area in cloud-free conditions. As such, they complement ground-based measurements by providing information over sparsely instrumented areas, albeit that significant differences may exist in both the type of information obtained and the temporal information from satellite and ground-based observations. In this paper, information from different types of satellite-based instruments is used to provide a 3-D climatology of aerosol properties over mainland China, i.e., vertical profiles of extinction coefficients from the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP), a lidar flying aboard the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite and the column-integrated extinction (aerosol optical depth – AOD) available from three radiometers: the European Space Agency (ESA)'s Along-Track Scanning Radiometer version 2 (ATSR-2), Advanced Along-Track Scanning Radiometer (AATSR) (together referred to as ATSR) and NASA's Moderate Resolution Imaging Spectroradiometer (MODIS) aboard the Terra satellite, together spanning the period 1995–2015. AOD data are retrieved from ATSR using the ATSR dual view (ADV) v2.31 algorithm, while for MODIS Collection 6 (C6) the AOD data set is used that was obtained from merging the AODs obtained from the dark target (DT) and deep blue (DB) algorithms, further referred to as the DTDB merged AOD product. These data sets are validated and differences are compared using Aerosol Robotic Network (AERONET) version 2 L2.0 AOD data as reference. The results show that, over China, ATSR slightly underestimates the AOD and MODIS slightly overestimates the AOD. Consequently, ATSR AOD is overall lower than that from MODIS, and the difference increases with increasing AOD. The comparison also shows that neither of the ATSR and MODIS AOD data sets is better than the other one everywhere. However, ATSR ADV has limitations over bright surfaces which the MODIS DB was designed for. To allow for comparison of MODIS C6 results with previous analyses where MODIS Collection 5.1 (C5.1) data were used, also the difference between the C6 and C5.1 merged DTDB data sets from MODIS/Terra over China is briefly discussed. The AOD data sets show strong seasonal differences and the seasonal features vary with latitude and longitude across China. Two-decadal AOD time series, averaged over all of mainland China, are presented and briefly discussed. Using the 17 years of ATSR data as the basis and MODIS/Terra to follow the temporal evolution in recent years when the environmental satellite Envisat was lost requires a comparison of the data sets for the overlapping period to show their complementarity. ATSR precedes the MODIS time series between 1995 and 2000 and shows a distinct increase in the AOD over this period. The two data series show similar variations during the overlapping period between 2000 and 2011, with minima and maxima in the same years. MODIS extends this time series beyond the end of the Envisat period in 2012, showing decreasing AOD.

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Spectral analysis and inversion of experimental codas

Geophysics ◽

10.1190/1.1443424 ◽

1993 ◽

Vol 58 (3) ◽

pp. 408-418 ◽

Cited By ~ 3

Author(s):

L. R. Jannaud ◽

P. M. Adler ◽

C. G. Jacquin

Keyword(s):

Spectral Analysis ◽

Characteristic Length ◽

Gaussian Model ◽

Seismic Survey ◽

Data Sets ◽

Data Set ◽

Anisotropic Elastic ◽

And Inversion ◽

Good Agreement

A method developed for the determination of the characteristic lengths of an heterogeneous medium from the spectral analysis of codas is based on an extension of Aki’s theory to anisotropic elastic media. An equivalent Gaussian model is obtained and seems to be in good agreement with the two experimental data sets that illustrate the method. The first set was obtained in a laboratory experiment with an isotropic marble sample. This sample is characterized by a submillimetric length scale that can be directly observed on a thin section. The spectral analysis of codas and their inversion yields an equivalent correlation length that is in good agreement with the observed one. The second data set is obtained in a crosshole experiment at the usual scale of a seismic survey. The codas are recorded, analysed, and inverted. The analysis yields a vertical characteristic length for the studied subsurface that compares well with the characteristic length measured by seismic and stratigraphic logs.

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Evaluative application of UKCP09‐based downscaled future weather years to simulate overheating risk in typical English homes

Structural Survey ◽

10.1108/ss-01-2013-0005 ◽

2013 ◽

Vol 31 (4) ◽

pp. 231-252 ◽

Cited By ~ 1

Author(s):

Rajat Gupta ◽

Matthew Gregg ◽

Hu Du ◽

Katie Williams

Keyword(s):

Climate Change ◽

Simulation Modelling ◽

Simulation Software ◽

Building Simulation ◽

Future Research ◽

Climate Projections ◽

Data Sets ◽

Data Set ◽

Content Type ◽

The Difference

PurposeTo critically compare three future weather year (FWY) downscaling approaches, based on the 2009 UK Climate Projections, used for climate change impact and adaptation analysis in building simulation software.Design/methodology/approachThe validity of these FWYs is assessed through dynamic building simulation modelling to project future overheating risk in typical English homes in 2050s and 2080s.FindingsThe modelling results show that the variation in overheating projections is far too significant to consider the tested FWY data sets equally suitable for the task.Research and practical implicationsIt is recommended that future research should consider harmonisation of the downscaling approaches so as to generate a unified data set of FWYs to be used for a given location and climate projection. If FWY are to be used in practice, live projects will need viable and reliable FWY on which to base their adaptation decisions. The difference between the data sets tested could potentially lead to different adaptation priorities specifically with regard to time series and adaptation phasing through the life of a building.Originality/valueThe paper investigates the different results derived from FWY application to building simulation. The outcome and implications are important considerations for research and practice involved in FWY data use in building simulation intended for climate change adaptation modelling.

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Matching Dendrochronological Dates with the Southern Hemisphere 14C Bomb Curve to Confirm Annual Tree Rings in Pseudolmedia rigida from Bolivia

Radiocarbon ◽

10.2458/azu_rc.57.18192 ◽

2015 ◽

Vol 57 (1) ◽

pp. 1-13 ◽

Cited By ~ 14

Author(s):

Laia Andreu-Hayles ◽

Guaciara M Santos ◽

David A Herrera-Ramírez ◽

Javier Martin-Fernández ◽

Daniel Ruiz-Carrascal ◽

...

Keyword(s):

Southern Hemisphere ◽

Tree Rings ◽

Geographic Location ◽

Data Sets ◽

Atmospheric Concentration ◽

Concentration Data ◽

Data Set ◽

Dendrochronological Analysis ◽

Before And After ◽

Ring Analysis

This study used high-precision radiocarbon bomb-pulse dating of selected wood rings to provide an independent validation of the tree growth periodicity of Pseudolmedia rigida (Klotzsch & H. Karst) Cuatrec. from the Moraceae family, collected in the Madidi National Park in Bolivia. 14C content was measured by accelerator mass spectrometry (AMS) in 10 samples from a single tree covering over 70 yr from 1939 to 2011. These preliminary calendar dates were determined by dendrochronological techniques and were also used to select the samples for 14C AMS. In order to validate these preliminary dates using the established Southern Hemisphere (SH) 14C atmospheric concentration data set, the targeted rings were selected to be formed during periods before and after the 14C bomb spike nuclear tests (i.e. 1950s–1960s). The excellent agreement of the dendrochronological dates and the 14C signatures in tree rings associated with the same dates provided by the bomb-pulse 14C atmospheric values for the SH (SHCal zone 1–2) confirms the annual periodicity of the observed growth layers, and thus the high potential of this species for tree-ring analysis. The lack of discrepancies between both data sets also suggests that there are no significant latitudinal differences between the 14C SHCal zone 1–2 curve and the 14C values obtained from the selected tree rings at this geographic location (14°33′S, 68°49′W) in South America. The annual resolution of P. rigida tree rings opens the possibility of broader applications of dendrochronological analysis for ecological and paleoclimatic studies in the Bolivian tropics, as well as the possibility of using wood samples from some tree species from this region to improve the quality of the bomb-pulse 14C SHCal curve at this latitude.

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