cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.25921/cnjq-ds80
title: NOAA/WDS Paleoclimatology - Foraminifer trace element data and experimental seawater properties from culture experiments on O. universa grown in 'Paleocene' seawater chemistry

description: The B/Ca ratio of planktic foraminiferal calcite, a proxy for the surface ocean carbonate system, displays large negative excursions during the Paleocene-Eocene Thermal Maximum (PETM, 55.9 Ma), consistent with rapid ocean acidification at that time. However, the B/Ca excursion measured at the PETM exceeds a magnitude that modern pH calibrations can explain. Numerous other controls on the proxy have been suggested, including foraminiferal growth rate and the total concentration of dissolved inorganic carbon (DIC). Here we present new calibrations for B/Ca versus the combined effects of pH and DIC in the symbiont-bearing planktic foraminifer Orbulina universa, grown in culture solutions with simulated Paleocene seawater elemental composition (high [Ca], low [Mg], and low total boron concentration ([B]T). We also investigate the isolated effects of low seawater [B]T, high [Ca], reduced symbiont photosynthetic activity, and average shell growth rate on O. universa B/Ca in order to further understand the proxy systematics and to determine other possible influences on the PETM records. We find that average shell growth rate does not appear to determine B/Ca in high calcite saturation experiments. In addition, our “Paleocene” calibration shows higher sensitivity than the modern calibration at low [B(OH)4-]/DIC. Given a large DIC pulse at the PETM, this amplification of the B/Ca response can more fully explain the PETM B/Ca excursion. However, further calibrations with other foraminifer species are needed to determine the range of foraminifer species-specific proxy sensitivities under these conditions for quantitative reconstruction of large carbon cycle perturbations.
description: This data set comprises the parameters and data from culture experiments in the planktic foraminifer Orbulina universa. Foraminiferal B/Ca and Mg/Ca, seawater trace element concentrations, and seawater carbonate chemistry parameters are reported. We also report estimated net lifetime growth rates, calculated from foraminiferal size, weight, and duration of life. These are not measured quantities and do not reflect instantaneous shell growth rate. Measurement precision- temperature: 0.1 degrees C, salinity: 0.1 PSU.
      Provided Keywords: B/Ca, Paleocene-Eocene Thermal Maximum, Orbulina universa, culture calibrations
DOI: 10.25921/creq-7n10
title: NOAA/WDS Paleoclimatology - Madagascar Holocene Stalagmite Stable Isotope Data

description: Petrographic features, mineralogy, and stable isotopes from two stalagmites, ANJB-2 and MAJ-5, respectively from Anjohibe and Anjokipoty caves, allow distinction of three intervals of the Holocene in NW Madagascar. The Malagasy early Holocene (between ca. 9.8 and 7.8ka) and late Holocene (after ca. 1.6ka) intervals (MEHI and MLHI, respectively) record evidence of stalagmite deposition. The Malagasy middle Holocene interval (MMHI, between ca. 7.8 and 1.6ka) is marked by a depositional hiatus of ca. 6500 years.

Deposition of these stalagmites indicates that the two caves were sufficiently supplied with water to allow stalagmite formation. This suggests that the MEHI and MLHI intervals may have been comparatively wet in NW Madagascar. In contrast, the long-term depositional hiatus during the MMHI implies it was relatively drier than the MEHI and the MLHI.

The alternating wet-dry-wet conditions during the Holocene may have been linked to the long-term migrations of the Intertropical Convergence Zone (ITCZ). When the ITCZ's mean position is farther south, NW Madagascar experiences wetter conditions, such as during the MEHI and MLHI, and when it moves north, NW Madagascar climate becomes drier, such as during the MMHI. A similar wet-dry-wet succession during the Holocene has been reported in neighboring locations, such as southeastern Africa. Beyond these three subdivisions, the records also suggest wet conditions around the cold 8.2ka event, suggesting a causal relationship. However, additional Southern Hemisphere high-resolution data will be needed to confirm this.
description: Stalagmite stable isotope (d18O and d13C) data from Anjohibe and Anjokipoty Caves, Madagascar for the past 10,000 years.
DOI: 10.25921/cstc-b161
title: NOAA/WDS Paleoclimatology - California Margin Bamboo Coral Barium Chemistry During the 20th Century

description: Reconstruction of past seawater d138/134Ba_NIST (barium-isotopic compositions) can augment existing proxies of water mass provenance and deep-ocean circulation. Deep-sea bamboo corals are uniquely poised to record Ba-isotopic variations, given their widespread oceanographic distribution and incorporation of ambient Ba in approximate proportion to that in surrounding seawater. However, the utility of such records requires knowing: the phases hosting Ba in deep-sea coral skeletons, that specimens faithfully capture modern Ba-isotopic chemistry, and that internal skeletal variability relates principally to historical variations in the composition of ambient seawater. We investigated each of these requirements using a stepped cleaning experiment, a 'core-top' comparison of eight live-collected specimens from the California margin (870-2,055 m) against ambient seawater, and through examination of historical variability in skeletal Ba chemistry, respectively. First, we report that non-carbonate phases minimally contribute to bamboo coral Ba/Ca, obviating the need for chemical cleaning of live-collected specimens. Second, using newly-obtained profiles of northeast Pacific Ba-isotopic chemistry, we observe that bamboo corals faithfully reflect ambient seawater with a taxonomically- and environmentally-invariant Ba-isotopic offset, D138/134Ba_coral-SW, of −0.37±0.03 ‰ (±2 SD, n = 8). The partition coefficient for Ba, KD_Ba, is similarly insensitive to taxonomy, but linearly decreases with depth. The driving mechanism is unresolved. Third, we find minimal Ba/Ca and Ba-isotopic variability in historical growth representing the past century. We interpret this invariance as evidencing the overall fidelity of deep-sea bamboo corals for ambient Ba chemistry over their long lifespans. The insensitivity of D138/134Ba_coral-SW to environmental gradients indicates that the Ba-isotopic composition of bamboo corals can be interpreted solely in terms of seawater composition, which should find myriad applications to the study of past ocean circulation over a range of timescales.
description: This dataset contains skeletal Ba/Ca and Ba isotopes from bamboo corals collected from the California Margin (N. Pacific Ocean). Details on coral chronologies and dating methodology can be found below and in Geyman et al. (2019). Seawater barium data published in the Geyman et al. (2019) calibration can be found at BCO-DMO (https://www.bco-dmo.org/dataset/770447 for IrnBru and https://www.bco-dmo.org/dataset/770368 for SAFe). Coral Mg/Ca and Sr/Ca data are of good quality and are provided here for reference, though they are largely beyond the scope of the originating study. Provided Keywords: barium isotopes, high-Mg calcite
DOI: 10.25921/c2bz-1557
title: NOAA/WDS Paleoclimatology - Paleo-pCO2 Database Piceance Creek Basin Eocene Nahcolite CO2 Data

description: Estimates of the atmospheric concentration of CO2, [CO2]atm, for the "hothouse" climate of the early Eocene climatic optimum (EECO) vary for different proxies. Extensive beds of the mineral nahcolite (NaHCO3) in evaporite deposits of the Green River Formation, Piceance Creek Basin, Colorado, USA, previously established [CO2]atm for the EECO to be >1125 ppm by volume (ppm). Here, we present experimental data that revise the sodium carbonate mineral equilibria as a function of [CO2] and temperature. Co-precipitation of nahcolite and halite (NaCl) now establishes a well-constrained lower [CO2]atm limit of 680 ppm for the EECO. Paleotemperature estimates from leaf fossils and fluid inclusions in halite suggest an upper limit for [CO2]atm in the EECO from the nahcolite proxy of ~1260 ppm. These data support a causal connection between elevated [CO2]atm and early Eocene global warmth, but at significantly lower [CO2]atm than previously thought, which suggests that ancient climates on Earth may have been more sensitive to a doubling of [CO2]atm than is currently assumed.
description: Paleo-CO2 derived from Eocene nahcolite from a Piceance Creek Basin, Colorado sediment core (Green River Formation), contributed to the Paleo-pCO2 Database
DOI: 10.25921/cwp8-va40
title: NOAA/WDS Paleoclimatology - Doangdoangan Besar, Indonesia Porites sp. d18O data from 1926-2010 CE

description: The Indonesian Throughflow (ITF) is a globally important ocean current that fuels heat and buoyancy fluxes throughout the Indo-Pacific and is known to covary in strength with the El Niño Southern Oscillation at interannual time scales. A climate system with a less well-quantified impact on the ITF is the East Asian Winter Monsoon (EAWM), which drives less saline surface waters from the South China Sea (SCS) into the Makassar Strait, obstructing surface ITF flow. We present a subannually resolved record of sea surface salinity (SSS) from 1927 to 2011 based on coral δ18O from the Makassar Strait that reveals variability in the relative contributions of different source waters to the surface waters of the Makassar Strait during the boreal winter monsoon. We find that the EAWM (January–March) strongly influences interannual SSS variability during boreal winter over the twentieth century (r = 0.54, p << 0.0001), impacting surface water circulation in the SCS and Indonesian Seas.
description: Measurements of d18O on a Porites coral collected from Doangdoangan Besar in the southern Makassar Strait. The d18O data were determined using isotope ratio mass spectrometry (IRMS)
DOI: 10.25921/cmja-e534
title: NOAA/WDS Paleoclimatology - Caucasus 250 Year May-June Precipitation Reconstruction

description: The Caucasus region experiences recurrent droughts that affect natural vegetation and the agriculture-based economies of several countries. Because meteorological records are in general scarce and of short timespan, little is known about the magnitude and frequency of past climate variability. Despite the recent increase of climate reconstructions for parts of Eurasia, no study has focused on past hydroclimate variability in the Caucasus. Here, we use a multispecies network of tree-ring width chronologies from the Lesser Caucasus to develop the first precipitation reconstruction for the region back to 1752 CE. Despite the high annual precipitation in the region, our reconstruction accounted for 51.2% of the variability in May-June precipitation from 1930 to 2001. In comparison with reconstructions in the eastern Mediterranean, our new reconstruction revealed important and distinct drought periods and pluvials. Previous winter North Atlantic Oscillation (NAO), and spring East Atlantic/Western Russia (EA/WR) and North Sea Caspian patterns are likely key drivers of May-June precipitation in the Caucasus and Anatolia. NAO appeared to negatively affect rainfall low-frequency variability while effects of EA/WR were more apparent at the interannual timescales. We also show a potential positive effect of Black Sea surface temperatures on May-June precipitation. In the Caucasus, May-June represents the period of major water supply in semi-arid areas and the period with the highest potential of water scarcity in mesic areas. It is also a period of potential catastrophic flood events. Thus, changes to the precipitation regime during this season will be critical to both human and natural systems of the Caucasus region.
description: May-June precipitation sum reconstruction in the Caucasus since 1752, based on 9 (nine) tree-ring width chronologies from the Western Caucasus in Turkey and the Republic of Georgia. The elevation of the tree-ring sites ranges between 700 and 2100 m asl. Five of the tree-ring width chronologies used were obtained from the International Tree Ring Data Bank (https://www.ncdc.noaa.gov/data-access/paleoclimatology-data/datasets/tree-ring) with the following site codes: GEOR004, GEOR005, GEOR008, GEOR010, TURK022
DOI: 10.25921/c3qh-2h10
title: NOAA/WDS Paleoclimatology - The International Tree-Ring Data Bank (ITRDB) Revisited

description: Aim

The International Tree-Ring Data Bank (ITRDB) is the most comprehensive database of tree growth. To evaluate its usefulness and improve its accessibility to the broad scientific community, we aimed to: (a) quantify its biases, (b) assess how well it represents global forests, (c) develop tools to identify priority areas to improve its representativity, and d) make available the corrected database.


Location
Worldwide.

Time period
Contributed datasets between 1974 and 2017.

Major taxa studied
Trees.

Methods
We identified and corrected formatting issues in all individual datasets of the ITRDB. We then calculated the representativity of the ITRDB with respect to species, spatial coverage, climatic regions, elevations, need for data update, climatic limitations on growth, vascular plant diversity, and associated animal diversity. We combined these metrics into a global Priority Sampling Index (PSI) to highlight ways to improve ITRDB representativity.

Results
Our refined dataset provides access to a network of >52 million growth data points worldwide. We found, however, that the database is dominated by trees from forests with low diversity, in semi-arid climates, coniferous species, and in western North America. Conifers represented 81% of the ITRDB and even in well-sampled areas, broadleaves were poorly represented. Our PSI stressed the need to increase the database diversity in terms of broadleaf species and identified poorly represented regions that require scientific attention. Great gains will be made by increasing research and data sharing in African, Asian, and South American forests.

Main conclusions
The extensive data and coverage of the ITRDB show great promise to address macroecological questions. To achieve this, however, we have to overcome the significant gaps in the representativity of the ITRDB. A strategic and organized group effort is required, and we hope the tools and data provided here can guide the efforts to improve this invaluable database.
description: Harmonized and corrected version of the ITRDB measurements files.
DOI: 10.25921/cjz5-3p65
title: NOAA/WDS Paleoclimatology - Southwest Florida Hurricane Database

description: Records of past climate and environment from historical references and documentary evidence such as church records, harvest dates, and diaries. Parameter keywords describe what was measured in this data set. Additional summary information can be found in the abstracts of papers listed in the data set citations.

description: Summaries of tropical cyclone histories in PDF format for 36 tropical cyclones which made landfall in southwest Florida 1848-2004 AD
DOI: 10.25921/cgfy-an47
title: NOAA/WDS Paleoclimatology - Winter temperature changes during the last 500 years in south China

description: The characteristics of the winter temperature changes in eight regions south of the Qinling Mountains and the Huai River in China during the last 500 years, based on the winter temperature indices or severe winter sequences, have been discussed in this paper.
description: Elevation estimated from GoogleEarth; rounded to 100 m
DOI: 10.25921/c0rm-0845
title: NOAA/WDS Paleoclimatology - Greenland Lakes Holocene Sediment Physical Properties Data

description: Records of past climate and environment derived from lake sediment records.  Parameter keywords describe what was measured in this data set.  Additional summary information can be found in the abstracts of papers listed in the data set citations.

description: Sediment reflectance and magnetic susceptibility data from 5 cores collected in 4 lakes in west and southwest Greenland
DOI: 10.25921/cz43-bg81
title: NOAA/WDS Paleoclimatology - Northwestern Atlantic Foraminifera d13C Data over the last Four Millennia

description: The Northwest Atlantic is a region of major climate change over the 20th century, affected by the weakening of the Atlantic meridional overturning circulation. To assess whether the ability of this region to absorb anthropogenic CO2 is also impacted by this change, we present the region’s first long-term carbon isotope (δ13C) time series of fossil foraminifera spanning the past 4,000 years.  These records reveal an unprecedented negative δ13C excursion driven by anthropogenic CO2 penetration into the surface ocean, the ‘Suess effect’ signal. This signal (amplitude -0.45‰) emerges in 1950 AD±15 with a decrease rate of 0.009±0.001‰/yr. This marine signal is ~30% of the atmospheric Suess effect and emerges over a century later. Based on current estimates of the ratio of δ13CDIC change to DIC change and limited constraints on surface ocean residence times, we calculate a mean anthropogenic CO2 uptake rate of 0.6±0.2 µmol (kg yr)-1 from 1950 to 2005.
DOI: 10.25921/ch2d-ab74
title: NOAA/WDS Paleoclimatology - Allen - Murganella - CAIN - ITRDB AUSL055

description: The ecology of the Australian monsoon tropics is fundamentally shaped by dry conditions between May and October followed by highly variable rainfall over the months of November to April. Due to its crucial ecological importance, a better understanding of past hydroclimate variability in the region is of great interest to land managers and custodians in this region. Short instrumental records also make highly resolved terrestrial palaeoclimate records for northern Australia prior to 1900 CE of considerable scientific importance. Here, we present two new well-replicated Callitris intratropica ring-width chronologies from Arnhem Land in northern Australia, one of which extends the tree-ring record in the region by another 86 years, back to 1761. Both chronologies have clearly defined regional patterns of correlations with temperature, precipitation, potential evapotranspiration and two drought indices (the self-calibrating Palmer Drought Severity Index (PDSI) and the Standardised Precipitation Evapotranspiration Index (SPEI)) across the lower latitudes of the Northern Territory. Results indicate considerable scope for hydroclimatic reconstructions based on C. intratropica for transitional periods into and out of the wettest time of the year. This suggests that such reconstructions would reflect variability in the duration of the wet period. While precipitation or streamflow reconstructions may be possible for both these transitional periods, drought reconstructions will be best focused on the months of March-May at the end of the wet period. Hydroclimate reconstructions would provide important baseline information for understanding the rate and magnitude of current regional climate change for these ecologically and culturally important transitional periods.
description: NOAA Template Raw Measurements file added 2020-01-15. July 2024: Elevation added by WDS-Paleo using get_elev_point() from the elevatr R package with the AWS Terrain Tiles (aws) and WGS 84 reference frame.
DOI: 10.25921/c8g2-7t10
title: NOAA/WDS Paleoclimatology - Katbakkies Pass, South Africa Holocene Multiproxy Rock Hyrax Midden Data

description: South Africa's southwestern Cape occupies a critical transition zone between Southern Hemisphere temperate (winter) and tropical (summer) moisture-bearing systems. In the recent geological past, it has been proposed that the relative influence of these systems may have changed substantially, but little reliable evidence regarding regional hydroclimates and rainfall seasonality exists to refine or substantiate the understanding of long-term dynamics. In this paper we present a mid-to late Holocene multi-proxy record of environmental change from a rock hyrax midden from Katbakkies Pass, located along the modern boundary between the winter and summer rainfall zones. Derived from stable carbon and nitrogen isotopes, fossil pollen and microcharcoal, these data provide a high resolution record of changes in humidity, and insight into changes in rainfall seasonality. Whereas previous work concluded that the site had generally experienced only subtle environmental change during the Holocene, our records indicate that significant, abrupt changes have occurred in the region over the last 7000 years. Contrary to expectations based on the site's location, these data indicate that the primary determinant of changes in humidity is summer rather than winter rainfall variability, and its influence on drought season intensity and/or length. These findings are consistent with independent records of upwelling along the southern and western coasts, which indicate that periods of increased humidity are related to increased tropical easterly flow. This substantially refines our understanding of the nature of temperate and tropical circulation system dynamics in SW Africa, and how changes in their relative dominance have impacted regional environments during the Holocene.
description: Please contact principle investigator Brian Chase to obtain these data. 

Katbakkies Pass, South Africa Holocene rock hyrax midden microcharcoal, stable isotope, and pollen data
DOI: 10.25921/cp3y-mq71
title: NOAA/WDS Paleoclimatology - Core top analysis of Calcium Carbonate from the Ontong-Java Plateau

description: Dissolution of calcite in deep ocean sediments, which is required to balance global marine CaCO3 production and burial fluxes, is still a poorly understood process. In order to assess the mechanisms of dissolution in sediments, we analyzed four multicore tops taken along a depth transect on the Ontong‐Java Plateau. These cores were taken directly on the equator, and span water column calcite saturation states from ∼0.93 to ∼0.74, allowing us to assess the effect of dissolution on carbonate sediment composition. The top 2 cm of each multicore was sectioned and sieved to separate coccolith from foraminiferal calcite, and the %CaCO3, δ13C, Δ14C, and Mg/Ca were evaluated. The mass ratio of coccoliths to foraminifera increases by a factor of 3 as a function of water depth, reflecting the preferential dissolution of foraminifera. Carbon isotope (δ13C and Δ14C) data suggest that most dissolution takes place at the sediment‐water interface and primarily affects foraminifera. Mg/Ca analyses indicate that the Mg content of the entire foraminiferal assemblage decreases as a function of dissolution. In contrast, coccolith dissolution takes place within the sediments, rather than at the interface. Together these two processes cause coccoliths to be up to 1,000 radiocarbon years younger than foraminifera from the same depth horizon. Despite this within‐sediment coccolith dissolution flux, sediments below the calcite saturation horizon remain enriched in coccolith calcite. Combined with global seafloor hypsometry and calcium carbonate content, this enrichment suggests that globally, coccoliths may outweigh foraminifera in deep ocean sediments by a factor of 1.8.
DOI: 10.25921/cgnv-r546
title: NOAA/WDS Paleoclimatology - de Graauw - Mill Point Barn - QUAL - ITRDB WV025

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: Chronology derived from log building (Mill Point Barn; MP). NOAA Template Raw Measurements file added 2020-03-09.