cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.25921/m9se-1691
title: NOAA/WDS Paleoclimatology - Torneträsk, Sweden 1100 Year Tree Ring d13C and Sunshine Reconstruction

description: This paper presents results from the first 1100 years of a long stable carbon isotope chronology currently in development from Scots Pine (Pinus sylvestris L.) trees growing in the Torneträsk region of northern Sweden. The isotope record currently comprises a total of 74 trees with a mean annual replication of >12, thereby enabling it to be compared directly with other tree-ring based palaeoclimate reconstructions from this region. In developing the reconstruction, several key topics in isotope dendroclimatology (chronology construction, replication, CO2 adjustment and age trends) were addressed.

The resulting carbon isotope series is calibrated against instrumental data from the closest meteorological station at Abisko (AD1913-2008) to provide a record of June-August sunshine for northern Fennoscandia. This parameter is closely linked to the direct control of assimilation rate; Photosynthetically Active Radiation (PAR) and the indirect measures; mean July-August temperature and percent cloud cover. The coupled response of summer sunshine and temperature in this region permits a multi-parameter comparison with a local reconstruction of past temperature variability based upon tree growth proxies to explore the stability of this coupling through time.

Several periods are identified where the temperature (X-ray density) and sunshine (stable carbon isotope ratio) records diverge. The most significant and sustained of these occur between c AD1200-1380 and c AD1550-1780, providing evidence for a cool, sunny, two-phase "Little Ice Age". Whilst summer sunshine reconstructed for the 20th century is significantly different from the mean of the last 1100 years (P < 0.01), conditions during the early mediaeval period are similar to those experienced in northern Fennoscandia during the 20th century (P > 0.01), so it is the 17th-18th, and to a lesser extent, the 13th centuries rather than the early mediaeval period that appear anomalous when viewed within the context of the last 1100 years. The observed departures between temperature and sunshine are interpreted as indicating a change in large-scale circulation associated with a southward migration of the Polar Front. Such a change, affecting the Northern Annular Mode (Arctic Oscillation) would result in more stable anticyclonic conditions (cool, bright, summers) over northern Fennoscandia, thus providing a testable mechanism for the development of a multi-phase, time-transgressive "Little Ice Age" across Europe.
description: Reconstruction of summer (June-August) sunshine for northern Fennoscandia for the last 1,100 years based on carbon isotopes from Scot Pine tree rings from Torneträsk, Sweden. 
IITRDB007
DOI: 10.25921/mvtp-xc87
title: NOAA/WDS Paleoclimatology - James Ross Island Ice Core 1000 Year Deuterium and Melt Data

description: Over the past 50 years, warming of the Antarctic Peninsula has been accompanied by accelerating glacier mass loss and the retreat and collapse of ice shelves. A key driver of ice loss is summer melting; however, it is not usually possible to specifically reconstruct the summer conditions that are critical for determining ice melt in Antarctic. Here we reconstruct changes in ice-melt intensity and mean temperature on the northern Antarctic Peninsula since AD 1000 based on the identification of visible melt layers in the James Ross Island ice core and local mean annual temperature estimates from the deuterium content of the ice. During the past millennium, the coolest conditions and lowest melt occurred from about AD 1410 to 1460, when mean temperature was 1.6C lower than that of 1981-2000. Since the late 1400s, there has been a nearly tenfold increase in melt intensity from 0.5 to 4.9%. The warming has occurred in progressive phases since about AD 1460, but intensification of melt is nonlinear, and has largely occurred since the mid-twentieth century. Summer melting is now at a level that is unprecedented over the past 1,000 years. We conclude that ice on the Antarctic Peninsula is now particularly susceptible to rapid increases in melting and loss in response to relatively small increases in mean temperature.
description: Deuterium (dD) and annual melt percentage and melt width data from the James Ross Island ice core, Antarctic Peninsula, for the last 1000 years. Annual averages are winter centred for isotopes, and summer centred for melt. Ages are given for the mid-year point. E.g. melt values assigned to 2006 are an average taken from ~July 2005 to ~June 2006. Data are given as annual averages from the top of the core back to 1807 AD. Age control back to 1807 is annually-defined based on annual cycles of nss-SO4. Beyond 1807 the age control is derived from the JRI-1 age scale (Mulvaney et al 2012, Nature), and data are given only as 11-year moving averages owing to the greater annual age uncertainty in this portion of the record.

Deuterium isotope data can be converted to temperature at this site using a temperature dependence of 6.4 per degC-1 (Abram et al.,2011, JGR). See also the Supplementary information provided in Mulvaney et al 2012, Nature, for the full Holocene deuterium isotope data for the JRI ice core
DOI: 10.25921/m1sz-rx54
title: NOAA/WDS Paleoclimatology - Bräker - Jussy JU - PPTM - ITRDB SWIT263

description: Tree ring data from the International Tree Ring Data Bank and World Data Center for Paleoclimatology archives.  Most data sets include raw treering measurements (most are annual ring width, with some collections of earlywood or latewood width or wood density), plus chronologies (standardized growth indices for a site compiled from multiple treering samples). Reconstructions of climate variables are included with some of these data sets.  Each data type is stored in a separate data file; the data type is coded into the file name. For details please see: http://www.ncdc.noaa.gov/paleo/treeinfo.htmll
description: NOAA Template Raw Measurements file added 2019-02-05.
DOI: 10.25921/m14z-5f10
title: NOAA/WDS Paleoclimatology - Paleo-pCO2 Database: Early Miocene CO2 reconstructions of Inner Mongolia

description: The early Miocene (~16–23 Ma) marks a critical transition in the Earth climate history from an Oligocene (~23–34 Ma) cooling trend towards the well-documented warm middle Miocene Climate Optimum at ~15 Ma. In eastern Asia, this transition links changes of key topographic features, such as the Tibetan plateau and the Mongolian plateau, and their impact on the reorganization of climate systems, such as the Eastern Asian summer monsoon. Yet the dynamics of the interplay among these factors remain poorly understood, precluding our understanding of future climate changes. Global temperatures during the early Miocene were warmer than the present day by 3–4 °C, which are seemingly incompatible with both the low (<300 ppm) and high (>800 ppm) ends of presently available reconstructions of atmospheric carbon dioxide (CO2). Here we report a rare co-occurrence of two redwoods, Metasequoia and Sequoia, from sediments of the early Miocene Hannuoba Formation in Zhuozi County in China’s Inner Mongolia at the southeastern margin of the current Mongolian plateau. The Zhuozi Metasequoia fossils possess uneven type cuticles, which dominate its living population but have rarely been reported throughout the abundant fossil record of this genus. By applying well constrained Franks model parameters obtained from these redwood fossils using a cleared leaf epidermis method, we estimated the early Miocene CO2 level at ~400 ppm, putting it at the lower end of the model requirement for sustaining a relatively warm global temperature during this period. Our Franks model estimates are ~100 ppm higher than that obtained using stomatal index method based on Metasequoia material, further confirming a systematic underestimation of ancient CO2 using the Metasequoia stomatal index method reported in previous analyses. We recommend a re-examination of previous CO2 reconstructions solely based upon Metasequoia’s inverse relationship between stomatal index and CO2 concentrations. Ultimately, the occurrence of these redwood fossils in Inner Mongolia is consistent with a weak or muted Eastern Asian summer monsoon in the region with the absence of an elevated Mongolian plateau during the early Miocene. A shift of moisture sources for the region accompanying the change from a Westerlies-dominated climate to the present-day monsoon dominated climate system occurred after the early Miocene time.
DOI: 10.25921/m2dr-t126
title: NOAA/WDS Paleoclimatology - Bräker - Ob dem Neuhaus, Malewagwald - ABAL - ITRDB SWIT211

description: Tree ring data from the International Tree Ring Data Bank and World Data Center for Paleoclimatology archives.  Most data sets include raw treering measurements (most are annual ring width, with some collections of earlywood or latewood width or wood density), plus chronologies (standardized growth indices for a site compiled from multiple treering samples). Reconstructions of climate variables are included with some of these data sets.  Each data type is stored in a separate data file; the data type is coded into the file name. For details please see: http://www.ncdc.noaa.gov/paleo/treeinfo.htmll
description: Purpose of Collection: 
# Thinning/Plentering
# 
# Cores and cross-sections are stored at: 
# disposed
# 
# References:
# Zingg, A., (1996) 
# Diameter and Basal Area Increment in Permanent Growth 
# and Yield Plots in Switzerland. 
# In: Spiecker, H.; Mielikainen, K.; Kohl, M.; Skovsgaard, J.P. (eds) 
# Growth Trends in European Forests. 
# European Forest Institute Research Report No.5.
# 
# 
# Notes: 
# Slope N 30%
# Formerly Biel_Tanne_n22_1992.fh
#  NOAA Template Raw Measurements file added 2019-02-05.
DOI: 10.25921/mvsd-ka32
title: NOAA/WDS Paleoclimatology - Atlantic and Pacific Regional 450 KYr Benthic d13C Stacks

description: The factors driving glacial changes in ocean overturning circulation are not well understood. On the basis of a comparison of 20 climate variables over the past four glacial cycles, the SPECMAP project proposed that summer insolation at high northern latitudes (that is, Milankovitch forcing) drives the same sequence of ocean circulation and other climate responses over 100-kyr eccentricity cycles, 41-kyr obliquity cycles and 23-kyr precession cycles. SPECMAP analysed the circulation response at only a few sites in the Atlantic Ocean, however, and the phase of circulation response has been shown to vary by site and orbital band. Here we test the SPECMAP hypothesis by measuring the phase of orbital responses in benthic d13C (a proxy indicator of ocean nutrient content) at 24 sites throughout the Atlantic over the past 425 kyr. On the basis of d13C responses at 3,000-4,010m water depth, we find that maxima in Milankovitch forcing are associated with greater mid-depth overturning in the obliquity band but less overturning in the precession band. This suggests that Atlantic overturning is strongly sensitive to factors beyond ice volume and summer insolation at high northern latitudes. A better understanding of these processes could lead to improvements in model estimates of overturning rates, which range from a 40 per cent increase to a 40 per cent decrease at the Last Glacial Maximum and a 10-50 per cent decrease over the next 140 yr in response to projected increases in atmospheric CO2.
description: The d13C records used in this study are collected from previous studies 
and primarily measured from the epibenthic taxon Cibicidoides wuellerstorfi. 
All records are placed on a common age model by aligning their benthic d18O 
records to the LR04 benthic d18O stack (Lisiecki and Raymo, 2005). 
The posted data include regional stacks (averages) of benthic d13C (%VPDB) 
from shallow North Atlantic sites (DSDP552, ODP980, ODP982, ODP983), 
mid-depth Atlantic sites (ODP925, ODP927, ODP928, GeoB1214), deep Atlantic 
sites (DP929, ODP1089, GeoB1041, GeoB1211), and deep Pacific sites (ODP677, 
ODP846, ODP849, RC13-110, V21-146). A proxy for mid-depth NADW (Dd13C_mid) 
is found by subtracting the deep Pacific d13c stack from the mid-depth 
Atlantic d13c stack.
DOI: 10.25921/mcfh-8297
title: NOAA/WDS Paleoclimatology - Reykjanes Ridge 230 Year Diatom August SST Reconstruction

description: August Sea Surface Temperatures (aSSTs) based on fossil diatom assemblages are generated with 2 year average resolution from a 230-year-long sediment core (Rapid 21-12B), from the Reykjanes Ridge in the subpolar North Atlantic. The results indicate a warming trend of ~0.5°C of the surface waters at the Reykjanes Ridge for the last 230 years. Superimposed on this warming trend there is a multidecadal to decadal aSST variability of up to 1°C. The interval from the 1770s to the 1830s represents the coldest period, whereas ~1860–1880 represents the warmest period during the last 230 years. The last 25 years is characterized by a warming trend showing strong decadal aSST variability with several warm years, but also the coldest years since the 1820s. The time of these cold years in the mid-1970s, -1980s and -1990s correspond with the documented great salinity anomalies (GSA) in the North Atlantic suggesting increased fluxes of cold, low-salinity waters from the Arctic during the last decades. The aSST record and the August North Atlantic Oscillation (aNAO) index show similar multidecadal-scale variability indicating a close coupling between the oceanic and atmospheric patterns. The aSST record shows a negative correlation with the aNAO indicating cold aSST during the positive aNAO trend and vice versa. Results suggest that the wind driven variation in volume fluxes of the North Atlantic surface waters could be the major mechanism behind the observed relationship.
description: A 230-year-long (~1773-2004 AD) August Sea Surface Temperature 
(aSST) record, with 2 year average resolution, from marine 
sediment core Rapid 21-12B collected in the northern subpolar 
North Atlantic.  The 54.3 cm long sediment box-core was recovered 
from the southern limb of the Gardar Drift on the eastern flank 
of Reykjanes Ridge, in the Iceland Basin, during the RRS Charles 
Darwin cruise 159 in 2004. The aSST reconstruction is based on 
fossil diatom assemblages and the weighted averaging partial 
least squares (WA-PLS) transfer function method.
DOI: 10.25921/mf4a-k406
title: NOAA/WDS Paleoclimatology - Red Sea 150KYr Relative Sea Level Reconstruction

description: Current global warming necessitates a detailed understanding of the relationships between climate and global ice volume. Highly resolved and continuous sea-level records are essential for quantifying ice-volume changes. However, an unbiased study of the timing of past ice-volume changes, relative to polar climate change, has so far been impossible because available sea-level records either were dated by using orbital tuning or ice-core timescales, or were discontinuous in time. Here we present an independent dating of a continuous, high-resolution sea-level record in millennial-scale detail throughout the past 150,000 years. We find that the timing of ice-volume fluctuations agrees well with that of variations in Antarctic climate and especially Greenland climate. Amplitudes of ice-volume fluctuations more closely match Antarctic (rather than Greenland) climate changes. Polar climate and ice-volume changes, and their rates of change, are found to covary within centennial response times. Finally, rates of sea-level rise reached at least 1.2 m per century during all major episodes of ice-volume reduction.
description: All datapoints in the Red Sea sea-level record (RSL) on its new chronology, including fully-propagated chronological uncertainties and RSL smoothed with a 1 kyr moving Gaussian filter
DOI: 10.25921/mggx-8663
title: NOAA/WDS Paleoclimatology - Diester-Haass et al. 2009 Atlantic Mid Miocene Paleoproductivity Data

description: A prominent, middle Miocene (17.5–13.5 Ma) carbon isotope excursion ubiquitously recorded in carbonate sediments has been attributed to enhanced marine productivity and sequestration of 13C depleted organic carbon in marine sediments or enhanced carbon burial in peat/lignite deposits on land. Here we test the hypothesis that the marine δ13C record reflects a change in productivity with proxy records from three Atlantic Ocean sites (Deep Sea Drilling Program Site 608 and Ocean Drilling Program Sites 925 and 1265). Our multiproxy approach is based on benthic foraminiferal accumulation rates, elemental ratios (Ba/Al and P/Al), the δ13C of bulk sedimentary organic matter, and dissolution indices. We compare these proxies to benthic foraminiferal δ13C values measured on the same samples. Our results indicate that marine paleoproductivity in the Atlantic Ocean is not related to the benthic foraminiferal δ13C excursion. A numerical box model confirms that marine productivity cannot account for the δ13C maximum. The model shows that sequestration of 1.5 × 1018 mol C in the terrestrial realm over a period of 3 Ma leads to a 0.9‰ δ13C increase in the deep ocean, which is near the observed records. Therefore, an increase in continental organic carbon sequestration is the most plausible way to enrich the ocean's carbon pool with 13C, which is consistent with coeval lignite deposits worldwide. The δ13C values of bulk sedimentary organic matter parallel the δ13C of dissolved inorganic carbon as reflected by benthic foraminiferal δ13C values suggesting no significant change in atmospheric pCO2 levels over the investigated period.
DOI: 10.25921/msjr-1z58
title: NOAA/WDS Paleoclimatology - Oppo et al. 2009 Makassar Strait 2,000 Year SST and d18Osw

description: Northern Hemisphere surface temperature reconstructions suggest that the late twentieth century was warmer than any other time during the past 500 years and possibly any time during the past 1,300 years. These temperature reconstructions are based largely on terrestrial records from extra-tropical or high-elevation sites; however, global average surface temperature changes closely follow those of the global tropics, which are 75% ocean. In particular, the tropical Indo-Pacific warm pool (IPWP) represents a major heat reservoir that both influences global atmospheric circulation and responds to remote northern high-latitude forcings. Here we present a decadally resolved continuous sea surface temperature (SST) reconstruction from the IPWP that spans the past two millennia and overlaps the instrumental record, enabling both a direct comparison of proxy data to the instrumental record and an evaluation of past changes in the context of twentieth century trends. Our record from the Makassar Strait, Indonesia, exhibits trends that are similar to a recent Northern Hemisphere temperature reconstruction. Reconstructed SST was, however, within error of modern values from about AD 1000 to AD 1250, towards the end of the Medieval Warm Period. SSTs during the Little Ice Age (approximately AD 1550–1850) were variable, and ∼0.5 to 1 °C colder than modern values during the coldest intervals. A companion reconstruction of δ18O of sea water—a sea surface salinity and hydrology indicator—indicates a tight coupling with the East Asian monsoon system and remote control of IPWP hydrology on centennial–millennial timescales, rather than a dominant influence from local SST variation.
DOI: 10.25921/mz57-hw87
title: NOAA/WDS Paleoclimatology - Yasuhara et al. 2009 Equatorial Atlantic ODP925 500KYr Benthic Ostracod Species Diversity Data

description: A benthic microfaunal record from the equatorial Atlantic Ocean over the past four glacial-interglacial cycles was investigated to understand temporal dynamics of deep-sea latitudinal species diversity gradients (LSDGs). The results demonstrate unexpected instability and high amplitude fluctuations of species diversity in the tropical deep ocean that are correlated with orbital-scale oscillations in global climate: Species diversity is low during glacial and high during interglacial periods. This implies that climate severely influences deep-sea diversity, even at tropical latitudes, and that deep-sea LSDGs, while generally present for the last 36 million years, were weakened or absent during glacial periods. Temporally dynamic LSDGs and unstable tropical diversity require reconsideration of current ecological hypotheses about the generation and maintenance of biodiversity as they apply to the deep sea, and underscore the potential vulnerability and conservation importance of tropical deep-sea ecosystems.
DOI: 10.25921/m36w-f623
title: NOAA/WDS Paleoclimatology - Griffiths et al. 2009 Liang Luar Indonesia Stalagmite d18O Data

description: The Australian-Indonesian summer monsoon affects rainfall variability and hence terrestrial productivity in the densely populated tropical Indo-Pacific region. It has been proposed that the main control of summer monsoon precipitation on millennial timescales is local insolation, but unravelling the mechanisms that have influenced monsoon variability and teleconnections has proven difficult, owing to the lack of high-resolution records of past monsoon behaviour. Here we present a precisely dated reconstruction of monsoon rainfall over the past 12,000 years, based on oxygen isotope measurements from two stalagmites collected in southeast Indonesia. We show that the summer monsoon precipitation increased during the Younger Dryas cooling event, when Atlantic meridional overturning circulation was relatively weak. Monsoon precipitation intensified even more rapidly from 11,000 to 7,000 years ago, when the Indonesian continental shelf was flooded by global sea-level rise. We suggest that the intensification during the Younger Dryas cooling was caused by enhanced winter monsoon outflow from Asia and a related southward migration of the intertropical convergence zone. However, the early Holocene intensification of monsoon precipitation was driven by sea-level rise, which increased the supply of moisture to the Indonesian archipelago.
description: Oxygen isotope data from two combined stalagmite records covering the period 12.7 ka to present from Liang Luar cave, Flores, Indonesia. Stalagmite d18O analyses were carried out on a GV2003 continuous-flow isotope ratio mass spectrometer at the University of Newcastle, Australia, and an automated Kiel carbonate preparation device coupled to a Finnigan MAT-251 mass spectrometer at the Research School of Earth Sciences, The Australian National University. 62 Th230/U234 dates were determined using TIMS and multi-collector ICP-MS at the University of Queensland and the University of Melbourne, Australia, respectively (see Suppl. Info in Griffiths et al., 2009). The d18O profile (Table S4 in Griffiths et al., 2009) consists of the spliced d18O records of stalagmites LR06-B1 (~8 year resolution) and LR06-B3 (~70 year resolution). Liang Luar cave, western Flores, Indonesia: 8º32'S, 120º26'E, 550m above sea level. UPDATE 3/2025: sample depths from the SISAL Global Speleothem Isotope Database v2 (https://doi.org/10.25921/s4ze-ve52) were added to LR06-B1 and LR06-B3 data tables.
DOI: 10.25921/ms97-p403
title: NOAA/WDS Paleoclimatology - Stahle - Palo Prieto Canyon - QUDG - ITRDB CA662

description: Tree ring data from the International Tree Ring Data Bank and World Data Center for Paleoclimatology archives.  Most data sets include raw treering measurements (most are annual ring width, with some collections of earlywood or latewood width or wood density), plus chronologies (standardized growth indices for a site compiled from multiple treering samples). Reconstructions of climate variables are included with some of these data sets.  Each data type is stored in a separate data file; the data type is coded into the file name. For details please see: http://www.ncdc.noaa.gov/paleo/treeinfo.htmll
description: NOAA Template Chronology file added 2018-12-20. NOAA Template Raw Measurements file added 2019-02-08.