Supplementary material to "Do Southern Hemisphere tree rings record past volcanic events?"

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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Supplementary material to "Surface ozone in the southern hemisphere: 20 years of data from a site with a unique setting in El Tololo, Chile"

10.5194/acp-2016-617-supplement ◽

2016 ◽

Author(s):

Julien G. Anet ◽

Martin Steinbacher ◽

Laura Gallardo ◽

Patricio A. Velásquez Álvarez ◽

Lukas Emmenegger ◽

...

Keyword(s):

Southern Hemisphere ◽

Surface Ozone ◽

Supplementary Material ◽

A Site

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Supplementary material to "Southern hemisphere bog persists as a strong carbon sink during droughts"

10.5194/bg-2017-97-supplement ◽

2017 ◽

Cited By ~ 1

Author(s):

Jordan P. Goodrich ◽

Dave I. Campbell ◽

Louis A. Schipper

Keyword(s):

Southern Hemisphere ◽

Carbon Sink ◽

Supplementary Material

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Variations of Radiocarbon in Tree Rings: Southern Hemisphere Offset Preliminary Results

Radiocarbon ◽

10.1017/s0033822200019184 ◽

1998 ◽

Vol 40 (3) ◽

pp. 1153-1159 ◽

Cited By ~ 40

Author(s):

F. G. McCormac ◽

A. G. Hogg ◽

T. F. G. Higham ◽

M. G. L. Baillie ◽

J. G. Palmer ◽

...

Keyword(s):

New Zealand ◽

Great Britain ◽

Northern Ireland ◽

Southern Hemisphere ◽

High Precision ◽

Tree Rings ◽

Precision Measurements ◽

Preliminary Results ◽

Queen's University

The Queen's University of Belfast, Northern Ireland and University of Waikato, Hamilton, New Zealand radiocarbon laboratories have undertaken a series of high-precision measurements on decadal samples of dendrochronologically dated oak (Quercus patrea) and cedar (Libocedrus bidwillii) from Great Britain and New Zealand, respectively. The results show a real atmospheric offset of 3.4 ± 0.6% (27.2 ± 4.7 14C yr) between the two locations for the interval ad 1725 to ad 1885, with the Southern Hemisphere being depleted in l4C. This result is less than the value currently used to correct Southern Hemisphere calibrations, possibly indicating a gradient in Δ14C within the Southern Hemisphere.

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ATMOSPHERIC RADIOCARBON FOR THE PERIOD 1950–2019

Radiocarbon ◽

10.1017/rdc.2021.95 ◽

2021 ◽

pp. 1-23

Author(s):

Quan Hua ◽

Jocelyn C Turnbull ◽

Guaciara M Santos ◽

Andrzej Z Rakowski ◽

Santiago Ancapichún ◽

...

Keyword(s):

Carbon Cycle ◽

Southern Hemisphere ◽

Northern Hemisphere ◽

Tree Rings ◽

Data Sets ◽

Previous Approach ◽

Monthly Data ◽

Smooth Curves ◽

Clean Air ◽

Increasing Demand

ABSTRACT This paper presents a compilation of atmospheric radiocarbon for the period 1950–2019, derived from atmospheric CO2 sampling and tree rings from clean-air sites. Following the approach taken by Hua et al. (2013), our revised and extended compilation consists of zonal, hemispheric and global radiocarbon (14C) data sets, with monthly data sets for 5 zones (Northern Hemisphere zones 1, 2, and 3, and Southern Hemisphere zones 3 and 1–2). Our new compilation includes smooth curves for zonal data sets that are more suitable for dating applications than the previous approach based on simple averaging. Our new radiocarbon dataset is intended to help facilitate the use of atmospheric bomb 14C in carbon cycle studies and to accommodate increasing demand for accurate dating of recent (post-1950) terrestrial samples.

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Radiocarbon in Annual Tree Rings from Thailand During the Pre-Bomb Period, Ad 1938–1954

Radiocarbon ◽

10.1017/s0033822200035979 ◽

2004 ◽

Vol 46 (2) ◽

pp. 925-932 ◽

Cited By ~ 13

Author(s):

Quan Hua ◽

Mike Barbetti ◽

Ugo Zoppi

Keyword(s):

Indian Ocean ◽

Southern Hemisphere ◽

Tree Rings ◽

Asian Monsoon ◽

Growing Season ◽

17Th Century ◽

Significant Source ◽

Northern Indian Ocean ◽

Air Mass

Annual tree rings from Thailand were analyzed by radiocarbon AMS for AD 1938–1954. The results showed no significant depletion in atmospheric 14C over Thailand during the pre-bomb period, even though the air mass to Thailand during the growing season of tree rings is transported over a potentially significant source of oceanic 14C-depleted CO2, out-gassing in the northern Indian Ocean. When compared with Washington and Chile for different periods from the 17th century to AD 1954, Thailand appears to have the characteristics of Southern Hemisphere 14C. This supports our previous finding that Thailand was strongly influenced by the entrainment of Southern Hemisphere air parcels in the southwest Asian monsoon (Hua et al. 2004). For Thailand, this effect is much stronger than the reduction of atmospheric 14C in association with CO2 out-gassing in the northern Indian Ocean.

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Recent Developments in Calibration for Archaeological and Environmental Samples

Radiocarbon ◽

10.1017/rdc.2020.22 ◽

2020 ◽

Vol 62 (4) ◽

pp. 1095-1117 ◽

Cited By ~ 8

Author(s):

J van der Plicht ◽

C Bronk Ramsey ◽

T J Heaton ◽

E M Scott ◽

S Talamo

Keyword(s):

Southern Hemisphere ◽

Northern Hemisphere ◽

Tree Rings ◽

Environmental Samples ◽

Varved Sediments ◽

Companion Article ◽

Recent Developments ◽

General Readership ◽

Paleolithic Archaeology ◽

Insight Into

ABSTRACTThe curves recommended for calibrating radiocarbon (14C) dates into absolute dates have been updated. For calibrating atmospheric samples from the Northern Hemisphere, the new curve is called IntCal20. This is accompanied by associated curves SHCal20 for the Southern Hemisphere, and Marine20 for marine samples. In this “companion article” we discuss advances and developments that have led to improvements in the updated curves and highlight some issues of relevance for the general readership. In particular the dendrochronological based part of the curve has seen a significant increase in data, with single-year resolution for certain time ranges, extending back to 13,910 calBP. Beyond the tree rings, the new curve is based upon an updated combination of marine corals, speleothems, macrofossils, and varved sediments and now reaches back to 55,000 calBP. Alongside these data advances, we have developed a new, bespoke statistical curve construction methodology to allow better incorporation of the diverse constituent records and produce a more robust curve with uncertainties. Combined, these data and methodological advances offer the potential for significant new insight into our past. We discuss some implications for the user, such as the dating of the Santorini eruption and also some consequences of the new curve for Paleolithic archaeology.

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