cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.25921/hea5-0k09
title: NOAA/WDS Paleoclimatology - Zhada Basin, SW Tibetan Plateau Miocene-Pleistocene Grain Size and Stable Isotope Data

description: Mechanisms controlling the long- and short-term variability of the Indian Summer Monsoon (ISM) and high-elevation environmental change have largely been examined using low-elevation or marine records with less emphasis on high-elevation non-marine records. We address this using a high-resolution, long-term record from upper Miocene-lower Pleistocene (~9.0-2.2 Ma) fluvio-lacustrine strata in the Zhada Basin, southwestern Tibetan Plateau. Long-term changes include the onset of lacustrine deposition, a decrease in mean grain size, and an increase in d18Ocarb and d13Ccarb values at ~6.0 Ma in response to basin closure following regional extension. This was followed by a return to palustrine/fluvial deposition, an increase in mean grain size, and a decrease in d18Ocarb and d13Ccarb values at ~3.5 Ma in response to tectonically driven long-term ISM weakening. Spectral analysis reveals that high-frequency variations in the d18Ocarb record are dominated by 100 and ~20 kyr cycles from ~6.0-2.2 Ma. Wavelet and spectral analysis of the most densely sampled interval (4.23-3.55 Ma), tuned to the record of daily insolation (21 June at 35N) confirms and highlights 100 and 20 kyr cycles. The tuned Pliocene d18Ocarb record is coherent with the record of Northern Hemisphere insolation at precession periods but not at obliquity or eccentricity periods. Additionally, the tuned d18Ocarb record is anticorrelated to the insolation record, indicating that stronger Northern Hemisphere insolation correlates with a stronger ISM. These results suggest that variations in daily insolation drove late Miocene-early Pleistocene high-frequency ISM variability and environmental changes in the high-elevation southwestern Tibetan Plateau.
description: Zhada Basin, southwestern Tibetan Plateau, grain size and stable isotope (d13C, d18O) data for the upper Miocene-lower Pleistocene (~9.0-2.2 Ma)
DOI: 10.25921/hdtk-s160
title: NOAA/WDS Paleoclimatology - Mid-Atlantic 70,000 Year Dust Deposition Fluxes

description: Sedimentary records of dust deposition in the subtropical Atlantic provide important constraints on millennial- and orbital-scale variability in atmospheric circulation and North African aridity. Constant flux proxies, such as extraterrestrial helium-3, yield dust flux records that are independent of the biases caused by lateral sediment transport and limited resolution that may be associated with age-model-derived mass accumulation rates. However, Atlantic dust records constrained using constant flux proxies are sparsely distributed and generally limited to the past 20 ka. Here we extend the Atlantic record of North African dust deposition to 70 ka using extraterrestrial helium-3 and measurements of titanium, thorium, and terrigenous helium-4 in two sediment cores collected at 26N and 29N on the Mid-Atlantic Ridge and compare results to model estimates for dust deposition in the subtropical North Atlantic. Dust proxy fluxes between 26N and 29N are well correlated, despite variability in lateral sediment transport, and underscore the utility of extraterrestrial helium-3 for constraining millennial-scale variability in dust deposition. Similarities between Mid-Atlantic dust flux trends and those observed along the Northwest African margin corroborate previous interpretations of dust flux variability over the past 20 ka and suggest that long distance transport and depositional processes do not overly obscure the signal of North African dust emissions. The 70 ka Mid-Atlantic record reveals a slight increase in North African dustiness from Marine Isotope Stage 4 through the Last Glacial Maximum and a dramatic decrease in dustiness associated with the African Humid Period. On the millennial-scale, the new records exhibit brief dust maxima coincident with North Atlantic cold periods such as the Younger Dryas, and multiple Heinrich Stadials. The correlation between Mid-Atlantic dust fluxes and previous constraints on North African aridity is high. However, precipitation exerts less control on dust flux variability prior to the African Humid Period, when wind variability governs dust emissions from consistently dry dust source regions. Thus, the Mid-Atlantic dust record supports the hypothesis that both aridity and wind strength drive dust flux variability across changing climatic conditions.
description: Dust flux data plus helium, titanium, and thorium measurements for 2 mid Atlantic sediment cores for the past 70,000 years
DOI: 10.25921/hbeq-my66
title: NOAA/WDS Paleoclimatology - North Iceland Holocene Chironomid-Inferred July Temperatures

description: The Holocene temperature history of Iceland is not well known, despite Iceland's climatically strategic location at the intersection of major surface currents in the high-latitude North Atlantic. Existing terrestrial records reveal spatially heterogeneous changes in Iceland's glacier extent, vegetation cover, and climate over the Holocene, but these records are temporally discontinuous and mostly qualitative. This paper presents the first quantitative estimates of temperatures throughout the entire Holocene on Iceland. Mean July temperatures are inferred based upon subfossil midge (Chironomidae) assemblages from three coastal lakes in northern Iceland. Midge data from each of the three lakes indicate broadly similar temperature trends, and suggest that the North Icelandic coast experienced relatively cool early Holocene summers and gradual warming throughout the Holocene until after 3 ka. This contrasts with many sites on Iceland and around the high-latitude Northern Hemisphere that experienced an early to mid-Holocene "thermal maximum" in response to enhanced summer insolation forcing. Our results suggest a heightened temperature gradient across Iceland in the early Holocene, with suppressed terrestrial temperatures along the northern coastal fringe, possibly as a result of sea surface conditions on the North Iceland shelf.
description: Chironomid-inferred July temperatures for 3 north Iceland lakes for the past 11,100 years
DOI: 10.25921/htwe-rx77
title: NOAA/WDS Paleoclimatology - T Lake, Palau Holocene Dinosterol H-Isotopic Composition and Abundance

description: The Holocene (0-11.7 ka BP) appears warm and stable in ice core and global temperature reconstructions as well as in transient climate simulations. This seeming quiescence of Earth's climate belies large secular changes in seasonal and zonal mean radiation receipts resulting from variations in orbital precession and obliquity. Here we show that the tropical Pacific, a key mediator of global climate, underwent a profound climatic shift during the Holocene. Hydrogen isotope ratios of the algal lipid dinosterol, isolated from marine lake sediments in Palau, increased by 50 permil between 7.7 and 4.5 ka BP, indicating a reduction in precipitation. This implied drying coincided with increased rainfall to the southwest of Palau in Borneo, weakened northern hemisphere monsoons, strengthened southern hemisphere monsoons, and an equatorward shift of terrestrial photosynthesis. A southward shift of the Intertropical Convergence Zone, forced by insolation, is the most likely cause of these climatic and biospheric changes.
description: Algal biomarker isotopic record from T Lake, Ngeruktabel, Palau, interpreted as indicative of rainfall across the Holocene
DOI: 10.25921/hgxa-mb39
title: NOAA/WDS Paleoclimatology - Gutiérrez - Woburn Abbey - QURO - ITRDB BRIT071

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/h96g-zg81
title: NOAA/WDS Paleoclimatology - Pearl - Destruction Brook - CHTH - ITRDB MA025

description: High-resolution paleoclimate records are essential for improving our understanding of internal variability and the detection and attribution of forced climate system responses. The densely populated northeastern United States is at risk from increasing temperatures, severe droughts, and extreme precipitation, but the region has limited annual and seasonal-resolution paleoclimate records beyond the instrumental record. Chamaecyparis thyoides, L. (B.S.P.), Atlantic white cedar, a wetland conifer found within 200 km of the Atlantic coastline of the United States, is a promising tree-ring proxy that can fill in these data gaps. Here, we develop and analyze a new network of Atlantic white cedar tree-ring chronologies across the northeastern United States and demonstrate that site selection is important for regional paleoclimate reconstructions. Ring width variability reflects winter through summer temperatures at inland and hydrologically stable sites in the northernmost section of the species' range. Ombrotrophic sites along the coast record hydrological signals and correlate with growing season precipitation. We demonstrate skillful regional climate field reconstructions for the last several centuries and show the increased skill from incorporating our moisture sensitive sites into broad-scale products like the North American Drought Atlas. This comprehensive understanding of the species' climate responses leads to a tree-ring network that provides the long-term multivariate climate context at multidecadal and centennial time scales for the large-scale ocean-atmospheric processes that influence the climate of the region. We use this network to examine the covariance of temperature and drought across the New England area over the past two centuries.
description: These data were collected as part of northeastern United States network of Atlantic white cedar. They were used to generate a gridded temperature reconstruction for the region. Two or three cores per tree were extracted from each tree and labelled as "A", "B" or "C" NOAA Template Raw Measurements file added 2020-05-11.
DOI: 10.15468/dl.ae49et
title: Occurrence Download

description: A dataset containing 1273 species occurrences available in GBIF matching the query:
{
 "and" : [
 "BasisOfRecord is Human Observation",
 "Continent is North America",
 "CoordinateUncertaintyInMeters 0.0-1000.0",
 "TaxonKey is Lepidium draba"
 ]
}

 The dataset includes 1273 records from 4 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0020862-251009101135966/datasets/export for details.
 
Data from some individual datasets included in this download may be licensed under less restrictive terms.
DOI: 10.25921/hgh1-qr37
title: NOAA/WDS Paleoclimatology - Pearl - Westminster Swamp - CHTH - ITRDB MA035

description: High-resolution paleoclimate records are essential for improving our understanding of internal variability and the detection and attribution of forced climate system responses. The densely populated northeastern United States is at risk from increasing temperatures, severe droughts, and extreme precipitation, but the region has limited annual and seasonal-resolution paleoclimate records beyond the instrumental record. Chamaecyparis thyoides, L. (B.S.P.), Atlantic white cedar, a wetland conifer found within 200 km of the Atlantic coastline of the United States, is a promising tree-ring proxy that can fill in these data gaps. Here, we develop and analyze a new network of Atlantic white cedar tree-ring chronologies across the northeastern United States and demonstrate that site selection is important for regional paleoclimate reconstructions. Ring width variability reflects winter through summer temperatures at inland and hydrologically stable sites in the northernmost section of the species' range. Ombrotrophic sites along the coast record hydrological signals and correlate with growing season precipitation. We demonstrate skillful regional climate field reconstructions for the last several centuries and show the increased skill from incorporating our moisture sensitive sites into broad-scale products like the North American Drought Atlas. This comprehensive understanding of the species' climate responses leads to a tree-ring network that provides the long-term multivariate climate context at multidecadal and centennial time scales for the large-scale ocean-atmospheric processes that influence the climate of the region. We use this network to examine the covariance of temperature and drought across the New England area over the past two centuries.
description: These data were collected as part of northeastern United States network of Atlantic white cedar. They were used to generate a gridded temperature reconstruction for the region. Two or three cores per tree were extracted from each tree and labelled as "A", "B" or "C" NOAA Template Raw Measurements file added 2020-05-11.
DOI: 10.6084/m9.figshare.30359624
title: Exact confidence intervals for the mixing distribution from binomial mixture distribution samples

description: We present a methodology for constructing pointwise confidence intervals for the cumulative distribution function and the quantiles of mixing distributions on the unit interval from binomial mixture distribution samples. No assumptions are made about the shape of the mixing distribution. The confidence intervals are constructed by inverting exact tests of composite null hypotheses regarding the mixing distribution. Our method may be applied to any deconvolution approach that produces test statistics whose distribution is stochastically monotone for a stochastic increase of the mixing distribution. We propose a hierarchical Bayes approach, which uses finite Polya Trees to model the mixing distribution, that provides stable and accurate deconvolution estimates without additional tuning parameters. Our main technical result establishes the stochastic monotonicity property of the test statistics produced by the hierarchical Bayes approach. Leveraging the need for the stochastic monotonicity property, we explicitly derive the smallest asymptotic confidence intervals that may be constructed using our methodology. This raises the question of whether it is possible to construct smaller confidence intervals for the mixing distribution without making parametric assumptions about its shape.
DOI: 10.25921/hsk9-s216
title: NOAA/WDS Paleoclimatology - Hughes - Prioksko-Terrasny Nature Reserve - PCAB - ITRDB RUSS277

description: We report new data on tree-ring growth in northern European Russia, a region with a hitherto relatively sparse tree-ring network. We explore its associations with climate variability. Areas, sampling locations and trees were selected for representativeness rather than climate sensitivity. Using tree rings from 651 conifers from six widely dispersed areas we show strong intercorrelation between trees within each major conifer species within and between areas. Regional composite tree-ring series for spruce and pine contain a major fraction of decadal and multidecadal variability. The most likely driver of this common variability is interannual to multidecadal climate variability. Gridded monthly instrumental climate data for the period 1902-2008, particularly mean temperature and total precipitation, were tested as predictors of each local species-specific tree-ring site chronology. The most consistent pattern emerged for spruce at all but the southernmost area. Cool and moist summers the year before growth were consistent drivers of spruce ring growth throughout the period, with no change in recent decades. Self-calibrating Palmer Drought Severity Index for prior summer was also a strong and consistent driver of spruce ring growth. For pine, there was a weaker but similarly stable association between larger rings and warm, moist conditions, in this case in the current summer. These associations were also identified at multidecadal time scales, particularly for spruce. On the other hand, the specific role of moisture variability in determining interannual to multidecadal variability in tree growth in this high latitude region raises questions about the relative vulnerability of spruce and pine there under global warming.
description: NOAA Template Raw Measurements file added 2020-01-15.
DOI: 10.6084/m9.figshare.30359624.v1
title: Exact confidence intervals for the mixing distribution from binomial mixture distribution samples

description: We present a methodology for constructing pointwise confidence intervals for the cumulative distribution function and the quantiles of mixing distributions on the unit interval from binomial mixture distribution samples. No assumptions are made about the shape of the mixing distribution. The confidence intervals are constructed by inverting exact tests of composite null hypotheses regarding the mixing distribution. Our method may be applied to any deconvolution approach that produces test statistics whose distribution is stochastically monotone for a stochastic increase of the mixing distribution. We propose a hierarchical Bayes approach, which uses finite Polya Trees to model the mixing distribution, that provides stable and accurate deconvolution estimates without additional tuning parameters. Our main technical result establishes the stochastic monotonicity property of the test statistics produced by the hierarchical Bayes approach. Leveraging the need for the stochastic monotonicity property, we explicitly derive the smallest asymptotic confidence intervals that may be constructed using our methodology. This raises the question of whether it is possible to construct smaller confidence intervals for the mixing distribution without making parametric assumptions about its shape.
DOI: 10.25921/hvq3-j585
title: NOAA/WDS Paleoclimatology - Heyerdahl fire data from Weitz, Palouse northwestern United States - IMPD USWEI001

description: Prairie-forest ecotones are ecologically important for biodiversity and ecological processes. While these ecotones cover small areas, their sharp gradients in land cover promote rich ecological interaction and high conservation value. Our objective was to understand how historical and current fire occurrences and human development influenced the Palouse Prairie-forest ecotone. We used General Land Office survey field notes about the occurrence of bearing trees to locate historical (1870s to 1880s) prairie, pine savanna, and forest at the eastern edge of the bioregion. We combined LANDFIRE Existing Vegetation classes to contrast historical land cover with current land cover. We reconstructed historical fire occurrence (1650 to 1900) from fire-scarred trees. We used fire and lightning records from 1992 to 2015 to interpret the role of people and lightning. Historically, the ecotone was a matrix of prairie with some pine savanna and forest (72%, 16%, and 12% of GLO points, respectively). The prairie and pine savanna have been largely converted to agriculture, perennial vegetation under the Conservation Reserve Program, or residential development while the forest has not been converted. Fires were historically frequent, occurring on average every 5 to 8 years at most sites. Lightning was not frequent but could likely have been sufficient to ignite fires that could spread readily given the rolling terrain and long fire season. Fire was far more frequent historically than currently. Lightning and people may ignite fires that spread readily in the future as conservation, restoration, and other land-use changes result in more continuous vegetation and hence fuel for fires. Understanding the past and potential future of fire in the Palouse Prairie bioregion may help us live with fire while conserving ecological values here and in similar prairie-forest ecotones.
description: This site was sampled as part of a project to reconstruct historical fire regimes on the eastern edge of the Palouse Prairie-forest ecotone in Idaho.

Ring-boundary fire scars were assigned to the preceding calendar year.

Several metadata files are provided with the FHX file.   -999 in any file indicates no data.

https://www.ncei.noaa.gov/pub/data/paleo/firehistory/firescar/northamerica/supplemental/uswei001-wei-tree-info.csv provides information about the fire-scarred trees, e.g., species and location.

The samples at this site were collected by Max Nielsen-Pincus as part of his PhD research at the University of Idaho, but were not reported in his dissertation.

Sampled on private property
DOI: 10.25921/h9pq-xx61
title: NOAA/WDS Paleoclimatology - Woodhouse - Turkey Creek Update - PIPO - ITRDB CO675

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: 10.15468/dl.vr2pgz
title: Occurrence Download

description: A dataset containing 2 species occurrences available in GBIF matching the query:
{
 "and" : [
 "TaxonKey is Cursorius cursor",
 "Country is South Sudan",
 "HasCoordinate is true"
 ]
}

 The dataset includes 2 records from 1 constituent datasets; see https://api.gbif.org/v1/occurrence/download/0020863-251009101135966/datasets/export for details.
 
Data from some individual datasets included in this download may be licensed under less restrictive terms.