cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.25921/x19v-8a30
title: NOAA/WDS Paleoclimatology - Southern Ocean Benthic Foraminifer Counts covering 35 to 62 Ma

description: The reliability of paleoproductivity proxies must be determined before assessing the role of the oceanic carbon (C) cycle in affecting past climate changes. We compare paleoproductivity records of newly generated micropaleontological data (benthic foraminiferal accumulation rates, BFAR) to those of existing geochemical data (reactive phosphorus [reactive P] mass accumulation rates [MAR] and biological barium [bio-Ba] MAR) for the same Paleogene aged sediments. Sediments are from the Atlantic (Maud Rise, Ocean Drilling Program [ODP] Sites 689/690) and the Indian (Kerguelen Plateau, ODP Site 738) sectors of the Southern Ocean. Reactive P MAR, but not bio-Ba MAR, correlates to varying degree with BFAR for all three sites investigated. Export productivity, delivery of organic C to the seafloor, and organic C burial calculated here using bio-Ba MAR, BFAR, and reactive P MAR, respectively, for these sites during the early Paleogene span two orders of magnitude (~0.01 to 1 g C cm-2 kyr-1). Differences in magnitude of reconstructed organic C fluxes are expected because different proxies record different aspects of the biological pump, and these aspects did not behave proportionally similar for all periods. Proxies studied here indicate that transfer efficiency, the fraction of exported organic matter from 100 m that reaches the deep ocean, was low for the early Paleogene Southern Ocean, similar to today. Despite this, absolute organic carbon burial was similar or higher than today because export productivity was similar or higher. Elevated temperatures may have increased both biological production and respiration in the early Paleogene Southern Ocean.
DOI: 10.25921/x54p-qa28
title: NOAA/WDS Paleoclimatology - Wax Lips Lake, NW Greenland Holocene and Last Interglacial Chironomid Inferred Temperature

description: Projections of future rates of mass loss from the Greenland Ice Sheet are highly uncertain because its sensitivity to warming is unclear. Geologic reconstructions of Quaternary interglacials can illustrate how the ice sheet responded during past warm periods, providing insights into ice sheet behavior and important tests for data-model comparisons. However, paleoclimate records from Greenland are limited: Early Holocene peak warmth has been quantified at only a few sites, and terrestrial sedimentary records of prior interglacials are exceptionally rare due to glacial erosion during the last glacial period. Here, we discuss findings from a lacustrine archive that records both the Holocene and the Last Interglacial (LIG) from Greenland, allowing for direct comparison between two interglacials. Sedimentary chironomid assemblages indicate peak July temperatures 4.0 to 7.0 C warmer than modern during the Early Holocene maximum in summer insolation. Chaoborus and chironomids in LIG sediments indicate July temperatures at least 5.5 to 8.5 C warmer than modern. These estimates indicate pronounced warming in northwest Greenland during both interglacials. This helps explain dramatic ice sheet thinning at Camp Century in northwest Greenland during the Early Holocene and, for the LIG, aligns with controversial estimates of Eemian warming from ice core data retrieved in northern Greenland. Converging geologic evidence for strong LIG warming is challenging to reconcile with inferred Greenland Ice Sheet extent during the LIG, and the two appear incompatible in many models of ice sheet evolution. An increase in LIG snowfall could help resolve this problem, pointing to the need for hydroclimate reconstructions from the region.
description: Chironomid and Chaoborus assemblage data and midge-inferred temperature reconstructions for core 14WLL2A Wax Lips Lake in northwest Greenland through the Holocene and Last Interglacial
DOI: 10.25921/x2xw-tq36
title: NOAA/WDS Paleoclimatology - Gutiérrez - Gutuli - PISY - ITRDB NORW016

description: Aim

The aim was to decipher Europe‐wide spatio-temporal patterns of forest growth dynamics and their associations with carbon isotope fractionation processes inferred from tree rings as modulated by climate warming.
Location

Europe and North Africa (30-70 N, 10 W-35 E).
Time period

1901-2003.
Major taxa studied

Temperate and Euro-Siberian trees.
Methods

We characterize changes in the relationship between tree growth and carbon isotope fractionation over the 20th century using a European network consisting of 20 site chronologies. Using indexed tree-ring widths (TRWi), we assess shifts in the temporal coherence of radial growth across sites (synchrony) for five forest ecosystems (Atlantic, boreal, cold continental, Mediterranean and temperate). We also examine whether TRWi shows variable coupling with leaf-level gas exchange, inferred from indexed carbon isotope discrimination of tree-ring cellulose (Delta13Ci).

Results

We find spatial autocorrelation for TRWi and Delta13Ci extending over a maximum of 1,000 km among forest stands. However, growth synchrony is not uniform across Europe, but increases along a latitudinal gradient concurrent with decreasing temperature and evapotranspiration. Latitudinal relationships between TRWi and Delta13Ci (changing from negative to positive southwards) point to drought impairing carbon uptake via stomatal regulation for water saving occurring at forests below 60 N in continental Europe. An increase in forest growth synchrony over the 20th century together with increasingly positive relationships between TRWi and Delta13Ci indicate intensifying impacts of drought on tree performance. These effects are noticeable in drought-prone biomes (Mediterranean, temperate and cold continental).
Main conclusions

At the turn of this century, convergence in growth synchrony across European forest ecosystems is coupled with coordinated warming-induced effects of drought on leaf physiology and tree growth spreading northwards. Such a tendency towards exacerbated moisture-sensitive growth and physiology could override positive effects of enhanced leaf intercellular CO2 concentrations, possibly resulting in Europe‐wide declines of forest carbon gain in the coming decades.
description: NOAA Template Raw Measurements file added 2020-01-15.
DOI: 10.25921/xp2r-tr27
title: NOAA/WDS Paleoclimatology - Sauchyn - Callum Creek - PSME - ITRDB CANA571

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: Upper Missouri River Basin Streamflow project NOAA Template Raw Measurements file added 2020-01-15.
DOI: 10.25921/x540-zx51
title: NOAA/WDS Paleoclimatology - Gutiérrez - Lainzer Tiergarte - QUPE - ITRDB AUST114

description: Aim

The aim was to decipher Europe‐wide spatio-temporal patterns of forest growth dynamics and their associations with carbon isotope fractionation processes inferred from tree rings as modulated by climate warming.
Location

Europe and North Africa (30-70 N, 10 W-35 E).
Time period

1901-2003.
Major taxa studied

Temperate and Euro-Siberian trees.
Methods

We characterize changes in the relationship between tree growth and carbon isotope fractionation over the 20th century using a European network consisting of 20 site chronologies. Using indexed tree-ring widths (TRWi), we assess shifts in the temporal coherence of radial growth across sites (synchrony) for five forest ecosystems (Atlantic, boreal, cold continental, Mediterranean and temperate). We also examine whether TRWi shows variable coupling with leaf-level gas exchange, inferred from indexed carbon isotope discrimination of tree-ring cellulose (Delta13Ci).

Results

We find spatial autocorrelation for TRWi and Delta13Ci extending over a maximum of 1,000 km among forest stands. However, growth synchrony is not uniform across Europe, but increases along a latitudinal gradient concurrent with decreasing temperature and evapotranspiration. Latitudinal relationships between TRWi and Delta13Ci (changing from negative to positive southwards) point to drought impairing carbon uptake via stomatal regulation for water saving occurring at forests below 60 N in continental Europe. An increase in forest growth synchrony over the 20th century together with increasingly positive relationships between TRWi and Delta13Ci indicate intensifying impacts of drought on tree performance. These effects are noticeable in drought-prone biomes (Mediterranean, temperate and cold continental).
Main conclusions

At the turn of this century, convergence in growth synchrony across European forest ecosystems is coupled with coordinated warming-induced effects of drought on leaf physiology and tree growth spreading northwards. Such a tendency towards exacerbated moisture-sensitive growth and physiology could override positive effects of enhanced leaf intercellular CO2 concentrations, possibly resulting in Europe‐wide declines of forest carbon gain in the coming decades.
description: NOAA Template Raw Measurements file added 2020-01-15.
DOI: 10.25921/xnjk-7v42
title: NOAA/WDS Paleoclimatology - Therrell - Sangamon River - QUAL - ITRDB IL022

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: Lincolns New Salem State Historical Site, October 29th, 2014, Q. alba NOAA Template Raw Measurements file added 2020-03-09.
DOI: 10.25921/xq6t-4b15
title: NOAA/WDS Paleoclimatology - de Graauw - McCoy Fort - QUAL - ITRDB WV024

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 (McCoy Fort; MCF). NOAA Template Raw Measurements file added 2020-03-09.
DOI: 10.15468/dl.cfsph7
title: Occurrence Download

description: A dataset containing 0 species occurrences available in GBIF matching the query:
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 The dataset includes 0 records from 0 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0024705-251009101135966/datasets/export for details.
DOI: 10.25921/x0s1-5980
title: NOAA/WDS Paleoclimatology - Redox trace metals and productivity in the Santa Barbara Basin for the past 200 years

description: Understanding dissolved oxygen variability in the ocean is limited by the short duration of direct measurements; however, sedimentary oxidation-reduction reactions can provide context for modern observations. Here we use bulk sediment redox-sensitive metal enrichment factors (MoEF, ReEF, and UEF) and scanning X-ray fluorescence records to examine annual-scale sedimentary oxygen concentrations in the Santa Barbara Basin from the Industrial Revolution (Common Era ~1850) to present. Enrichments are linked to measured bottom water oxygen concentrations after 1986. We reveal gradual intensification of the coastal oxygen minimum zone (OMZ) on the southern California margin coinciding with the twentieth century anthropogenic warming trend that leads to reduced oxygen solubility and greater stratification. High-frequency interannual oscillations become more prominent over the last three decades. These are attributed to local “flushing events” triggered by the transition from El Niño to La Niña conditions, which further amplify changes in the extratropical southern Californian OMZ.
description: Trace element concentrations and total organic carbon
     Provided Keywords: Redox, productivity, Santa Barbara Basin, oxygen minimum zone
DOI: 10.15468/dl.wmztmb
title: Occurrence Download

description: A dataset containing 0 species occurrences available in GBIF matching the query:
{
 "and" : [
 "TaxonKey is one of (Struthioniformes)",
 "HasCoordinate is true",
 "HasGeospatialIssue is false",
 "Year is greater than or equal to 1980",
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 The dataset includes 0 records from 0 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0024706-251009101135966/datasets/export for details.
DOI: 10.25921/x8pq-5020
title: NOAA/WDS Paleoclimatology - Oxygen isotope and sea surface temperature records from Site 1125 in the southwest Pacific, 0.13-2.8 Ma

description: The transition from the warm, stable climate of the Pliocene to the progressively colder glaciations of the Pleistocene, as well as the climate system's evolving response to stationary orbital forcing over the Pleistocene, beg important questions about fundamental climate processes relevant to understanding the impacts of modern anthropogenic forcing of the Earth's energy budget. Here, we gain insight into the evolution of Plio-Pleistocene climate by generating an alkenone-derived, orbitally resolved sea surface temperature (SST) record from Ocean Drilling Program Site 1125 in the southwest Pacific. We compare our data set to midlatitude and equatorial SST records and to the benthic ∂18O signal in order to evaluate similarities and differences in climate response between the hemispheres and across latitudes over the Plio-Pleistocene. Secular trends indicate first-order symmetry between the Northern and Southern Hemispheres in the magnitude of mean, glacial, and interglacial cooling. However, the tight coupling that is observed on both secular and orbital timescales between Northern Hemisphere, high latitude, and tropical upwelling climate throughout the last 4 Ma does not extend to Southern Hemisphere climate records as Northern Hemisphere glaciation intensifies in the late Pliocene. The 41-kyr signal remains weak at Site 1125 across the late Pliocene transition but strengthens in conjunction with a major increase in global climate system sensitivity to obliquity forcing beginning around 1.8 Ma. Our analysis points to regionally varied responses across the late Pliocene transition and the emergence of a global feedback mechanism and strengthened obliquity-band climate sensitivity just prior to the mid-Pleistocene transition.
description: Provided Keywords: sea surface temperature, alkenone paleothermometry, Plio-Pleistocene climate, Milankovitch forcing
DOI: 10.15468/dl.9zsyt2
title: Occurrence Download

description: A dataset containing 0 species occurrences available in GBIF matching the query:
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 "TaxonKey is one of (Scaphopoda)",
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 The dataset includes 0 records from 0 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0024708-251009101135966/datasets/export for details.
DOI: 10.25921/x5zv-ar39
title: NOAA/WDS Paleoclimatology - Gol-e-Zard Cave, Iran Mid-Holocene Isotope and Trace Metal Data

description: The extent to which climate change causes significant societal disruption remains controversial. An important example is the decline of the Akkadian Empire in northern Mesopotamia ~4.2 ka, for which the existence of a coincident climate event is still uncertain. Here we present an Iranian stalagmite record spanning 5.2 ka to 3.7 ka, dated with 25 U/Th ages that provide an average age uncertainty of 31 y (1sigma). We find two periods of increased Mg/Ca, beginning abruptly at 4.51 and 4.26 ka, and lasting 110 and 290 y, respectively. Each of these periods coincides with slower vertical stalagmite growth and a gradual increase in stable oxygen isotope ratios. The periods of high Mg/Ca are explained by periods of increased dust flux sourced from the Mesopotamia region, and the abrupt onset of this dustiness indicates threshold behavior in response to aridity. This interpretation is consistent with existing marine and terrestrial records from the broad region, which also suggest that the later, longer event beginning at 4.26 ka is of greater regional extent and/or amplitude. The chronological precision and high resolution of our record indicates that there is no significant difference, at decadal level, between the start date of the second, larger dust event and the timing of North Mesopotamia settlement abandonment, and furthermore reveals striking similarity between the total duration of the second dust event and settlement abandonment. The Iranian record demonstrates this region's threshold behavior in dust production, and its ability to maintain this climate state for multiple centuries naturally.
description: Mid-Holocene (4.9-3.7ka) stable isotope (d18O, d13C) and trace metal (Mg/Ca, Sr/Ca, Ba/Ca, S/Ca) data from Stalagmite GZ14-1 collected in Gol-e-Zard Cave, Iran
Provided Keywords: 4.2 ka event, stalagmite, drought, Mesopotamia, dust
DOI: 10.15468/dl.pjxr56
title: Occurrence Download

description: A dataset containing 0 species occurrences available in GBIF matching the query:
{
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 "TaxonKey is one of (Struthioniformes)",
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 The dataset includes 0 records from 0 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0024704-251009101135966/datasets/export for details.
DOI: 10.25921/x5hz-h169
title: NOAA/WDS Paleoclimatology - Chao Phraya River, Thailand 202 Year Peak Season Flow Reconstruction

description: We present a statistically robust reconstruction of Thailand's Chao Phraya River peak season streamflow (CPRPF) that spans the 202 years from 1804 to 2005 CE. Our reconstruction is based on tree ring d18O series derived from three Pinus merkusii sites from Laos and Thailand. The regional d18O index accounts for 57% of the observed variance of CPRPF. Spatial correlation and 21-year running correlation analyses reveal that CPRPF is greatly influenced by regional precipitation variations associated with the El Nino-Southern Oscillation (ENSO). Periods of enhanced and reduced ENSO activity are associated with strong and weak ENSO-streamflow correlation, respectively. At the longer timescale, the Pacific Decadal Oscillation (PDO) appears to modulate the ENSO-streamflow correlations, with the most extreme flood events along the Chao Phraya River occurring during periods of increased frequency of La Nina events that coincide with extended cold phases of the PDO. The CPRPF reconstruction could aid management planning for Thailand's water resources.
description: Streamflow reconstruction of Thailand's Chao Phraya River peak-season (August-November) flow based on tree-ring d18O data, for the past 202 years
DOI: 10.25921/x3nx-xb45
title: NOAA/WDS Paleoclimatology - Gut - Elm-Raminerwald - PCAB - ITRDB SWIT379

description: The pairwise statistical comparison of ring-width series is the basic analysis of dendro-provenancing studies. It is assumed that statistical proximity indicates similar provenance, but this assumption often remains untested. Especially for small areas with high topographic complexity, it is unknown to what extent statistical proximity and geographical provenance are correlated.

In this paper, dendro-provenancing is framed as a search for statistical Nearest Neighbors. The 'k-Nearest Neighbors leave one-out cross-validation' process (k-NN) is proposed as a method for validating dendro-provenancing approaches. Furthermore, it allows researchers to consistently compare and evaluate different proximity measures with respect to their suitability for dendro-provenancing. The validation process is demonstrated on a data set of 401 ring-width series of Norway spruce (Picea abies (L.) H. Karst.) encompassing 15 sites along elevational gradients in north-eastern Switzerland. Moreover, a new type of plot, the so-called scissor plot, is introduced to visualize the k-NN validation process.

Results indicate that dendro-provenancing depends heavily on differences in between sites high-frequency signal. Mean classification success for the relevant stages of the k-NN (CSRopen) ranged from 71.8% to 79.2% for the best performing measures. Classification errors occurred mainly between sites at elevations of 1000-1198 m a.s.l. At all other elevations and between different regions of the study area, only moderate differences in classification performance were detected. Thus, the results indicate that dendro-provenancing may be principally feasible even in a small region as studied here.
description: dendro-provenance study NOAA Template Raw Measurements file added 2020-03-09.