cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.25921/ge74-5p96
title: NOAA/WDS Paleoclimatology - Southeastern Tibetan Plateau 500 Year scPDSI Reconstruction

description:  Rapid warming has been observed in the high-altitude areas around the globe, but the implications on moisture change are not fully understood. Here we use tree-rings to reveal common moisture change on the southeastern Tibetan Plateau (TP) during the past five centuries, and show that regional moisture change in late spring to early summer (April-June) is closely related to large-scale temperature anomaly over the TP, with increased moisture coincident with periods of high temperature. The most recent pluvial during the 1990s-2000s is likely the wettest for the past five centuries, which coincides with the warmest period on the TP during the past millennium. Dynamic analysis reveals that vertical air convection is enhanced in response to anomalous TP surface warming, leading to an increase in lower-tropospheric humidity and effective precipitation over the southeastern TP. The coherent warm-wet relationship identified in both tree-rings and dynamic analysis implies a generally wetter condition on the southeastern TP under future warming.
description: Southeastern Tibetan Plateau April-June self-calibrating Palmer Drought Severity Index (scPDSI) reconstruction for the past 500 years, based on two Abies forestii tree-ring chronologies from the southern Shaluli Mountains. The tree-ring data are archived in the International Tree-Ring Data Bank (ITRDB), site codes CHIN019 and CHIN075.
DOI: 10.25921/gsdc-bx75
title: NOAA/WDS Paleoclimatology - Köhl - TiBiTi - GOGL - ITRDB SUR001

description: The world’s forests play a pivotal role in the mitigation of global climate change. By photosynthesis they remove CO2 from the atmosphere and store carbon in their biomass. While old trees are generally acknowledged for a long carbon residence time, there is no consensus on their contribution to carbon accumulation due to a lack of long-term individual tree data. Tree ring analyses, which use anatomical differences in the annual formation of wood for dating growth zones, are a retrospective approach that provides growth patterns of individual trees over their entire lifetime. We developed time series of diameter growth and related annual carbon accumulation for 61 trees of the species Cedrela odorata L. (Meliacea), Hymenaea courbaril L. (Fabacea) and Goupia glabra Aubl. (Goupiacea). The trees grew in unmanaged tropical wet-forests of Suriname and reached ages from 84 to 255 years. Most of the trees show positive trends of diameter growth and carbon accumulation over time. For some trees we observed fluctuating growth—periods of lower growth alternate with periods of increased growth. In the last quarter of their lifetime trees accumulate on average between 39 percent (C. odorata) and 50 percent (G. glabra) of their final carbon stock. This suggests that old-growth trees in tropical forests do not only contribute to carbon stocks by long carbon resistance times, but maintain high rates of carbon accumulation at later stages of their life time.
description: NOAA Template Raw Measurements file added 2019-04-29.
DOI: 10.25921/g4sm-hq23
title: NOAA/WDS Paleoclimatology - Pisaric - Deadwood Mackenzie Delta - PCGL - ITRDB CANA521

description: We present a reconstruction of June-July minimum temperatures since AD 1245 for the Mackenzie Delta region based on a 29-site network of white spruce (Picea glauca) ring-width series. Most but not all trees experienced a divergent temperature-growth response, similar to the divergence that has affected other white spruce trees across Yukon and Alaska. However, divergence in the study region began as early as AD 1900 and we have documented our methods to avoid including divergent signals in the reconstruction. Calibration/verification testing based on local temperature data, and multi-century coherence with nearby and large-scale temperature proxy records, confirm that our reconstruction is robust. The reconstruction shows cool conditions in the late 13th, early 18th and early 19th centuries, corresponding with solar minima and increased volcanism. These cool periods are interrupted by warm periods consistent with early to mid-20th century warmth. The late 20th century is the warmest interval, and the last decade is estimated to be 1.4C warmer than any decade before the mid-20th century. The reconstructed climate history corroborates other proxy-based inferences and supports the notion that high-latitude regions such as the Mackenzie Delta have experienced rapid warming in recent decades that is exceptional in the last eight centuries.
description: NOAA Template Raw Measurements file added 2019-01-27. NOAA Template Raw Measurements file added 2019-02-04.
DOI: 10.25921/ghgj-0c31
title: NOAA/WDS Paleoclimatology - Baisan fire data from Hitchcock - IMPD USHIT001

description: Records of past fire occurrence from tree rings, charcoal found in lake sediments, and other proxies. 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.  Additional information on the International Multiproxy Database (IMPD) data set procedures are also available.
DOI: 10.25921/gdws-cm90
title: NOAA/WDS Paleoclimatology - Plio-Pleistocene astronomical timescale

description: An astronomically calibrated timescale has recently been established [Hilgen, 1991a, b] for the Pliocene and earliest Pleistocene based on the correlation of dominantly precession controlled sedimentary cycles (sapropels and carbonate cycles) in Mediterranean marine sequences to the precession time series of the astronomical solution of Berger and Loutre [1991] (hereinafter referred to as Ber90). Here we evaluate the accuracy of this timescale by (1) comparing the sedimentary cycle patterns with 65°N summer insolation time series of different astronomical solutions and (2) a cross-spectral comparison between the obliquity-related components in the 65°N summer insolation curves and high-resolution paleoclimatic records derived from the same sections used to construct the timescale. Our results show that the carbonate cycles older than 3.5 m.y. should be calibrated to one precession cycle older than previously proposed. Application of the astronomical solution of Laskar [1990] (hereinafter referred to as La90) with present-day values for the dynamical ellipticity of the Earth and tidal dissipation by the Sun and Moon results in the best fit with the geological record, indicating that this solution is the most accurate from a geological point of view. Application of Ber90, or La90 solutions with dynamical ellipticity values smaller or larger than the present-day value, results in a less obvious fit with the geological record. This implies that the change in the planetary shape of the Earth associated with ice loading and unloading near the poles during the last 5.3 million years was too small to drive the precession into resonance with the perturbation term, s6−g6+g5, of Jupiter and Saturn. Our new timescale results in a slight but significant modification of all ages of the sedimentary cycles, bioevents, reversal boundaries, chronostratigraphic boundaries, and glacial cycles. Moreover, a comparison of this timescale with the astronomical timescales of ODP site 846 [Shackleton et al., 1995a, b] and ODP site 659 [Tiedemann et al., 1994] indicates that all obliquity-related glacial cycles prior to ∼4.7 Ma in ODP sites 659 and 846 should be correlated with one obliquity cycle older than previously proposed.
DOI: 10.25921/gvxy-3j49
title: NOAA/WDS Paleoclimatology - Equatorial Atlantic Sediment Composition and Radionuclide Data

description: The Silicic Acid Leakage Hypothesis (SALH) suggests that, during glacial periods, excess silicic acid was transported from the Southern Ocean to lower latitudes, which favored diatom production over coccolithophorid production and caused a drawdown of atmospheric CO2. Downcore records of 230Th-normalized opal fluxes and 231Pa/230Th ratios from seven equatorial Atlantic cores were used to reconstruct diatom productivity over the past 30 ka (where a is years) and to test the SALH. Downcore records of 231Pa/230Th ratios and opal fluxes are highly correlated, suggesting that they constitute a production-based record of opal flux. Opal flux records support the SALH in that glacial opal burial exceeded Holocene burial by 1.8 Gt opal/ka in the area 0°–40°W and 5°N–5°S. Earlier results from the eastern equatorial Pacific Ocean showed the opposite trend, with greater Holocene than glacial opal burial, but approximately the same magnitude of difference between glacial and interglacial opal burial. We suggest four (nonexclusive) scenarios to explain the data from both basins: (1) Increased upwelling in the equatorial Atlantic and El Niño-like conditions suppressing upwelling in the eastern equatorial Pacific altered the overall nutrient supply to both basins; (2) Si leaked from the Southern Ocean because of Fe fertilization, but was prevented from upwelling in the equatorial Pacific because of El Niño-like conditions during the LGM; (3) Si leaked from the Southern Ocean because diatom productivity was limited by increased sea ice extent and was again prevented from upwelling in the equatorial Pacific; or (4) changes in ocean circulation related to the decreased input of Agulhas water to the glacial South Atlantic provided excess dissolved Si to the equatorial Atlantic Ocean. A deglacial opal pulse is seen in both the Atlantic and Pacific Oceans. All four scenarios and the presence of the common deglacial opal pulse suggest a common driver in the Southern Ocean.
DOI: 10.25921/gxz4-v434
title: NOAA/WDS Paleoclimatology - LGM ocean model data exploring the role of ocean circulation and iron fertilization in the sequestration of atmospheric CO2

description: The role of glacial ocean circulation and iron fertilization in the sequestration of atmospheric CO2 are not well understood. Here we use a physical-biogeochemical model constrained by carbon and nitrogen isotopes to explore the effects of Atlantic Meridional Overturning Circulation (AMOC) and Southern Ocean iron fertilization on the distributions of these isotopes and ocean carbon storage. We find that a surprisingly weak (6-9 Sv) and shallow AMOC maximizes carbon storage and best reproduces the glacial sediment data. Increasing the atmospheric soluble iron flux in the Southern Ocean intensifies export production, carbon storage, and improves agreement with reconstructions. Our best fitting model suggests that a weak, shallow AMOC and enhanced iron fertilization conspired to enhance carbon storage in the glacial ocean.
description: The folders in directory https://www.ncei.noaa.gov/pub/data/paleo/gcmoutput/muglia2017-sci contain the results presented in the paper "Weak overturning circulation and increased iron fertilization maximized carbon storage in the glacial ocean", by Juan Muglia, Luke C. Skinner, and Andreas Schmittner, currently in preparation for the  journal Science. Output files are tavg and tsi netcdf files. The rest of the files are necessary to run the model, if more experiments are going to be carried out.
DOI: 10.25921/gbrs-e554
title: NOAA/WDS Paleoclimatology - Northwest Himalaya 576 Year Standardized Precipitation Index Reconstruction

description: Hydroclimatic variability driven by global warming in the climatically vulnerable cold semi-arid to arid northwest (NW) Himalaya is poorly constrained due to paucity of continuous weather records and annually resolved proxies. Applying a network of annually resolved tree-ring-width chronologies from semi-arid region of Kishtwar, Jammu and Kashmir, India, we reconstructed April-May standardized precipitation index extending back to A.D. 1439 (576 years). The reconstructed series is featured by the most conspicuous long-term droughts during the 15th to early 17th centuries followed by a general wetting, with 1984-2014 being the wettest interval in the past 576 years. The data, consistent with other independently developed tree-ring-based hydrological records from cold semi-arid to arid NW Himalaya and Karakoram, point to an increased regional wetting in the recent decades. Such an increased wetting might have led to the anomalous behaviour of glaciers in the NW Himalaya and Karakoram in contrast to the general receding trends in the central and eastern Himalaya.
description: Standardized precipitation index reconstruction for April/May, 1439-2014 CE, based on 5 NW Himalaya tree-ring chronologies.
DOI: 10.25921/gh90-tm49
title: NOAA/WDS Paleoclimatology - Peterson - Hart's Pass N2 - ABLA - ITRDB WA073

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.
DOI: 10.25921/g4vj-v340
title: NOAA/WDS Paleoclimatology - Holmes - Hueicolla - PLUV - ITRDB CHIL014

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 2018-12-13. NOAA Template Raw Measurements file added 2019-04-29.
DOI: 10.25921/gtvq-9z90
title: NOAA/WDS Paleoclimatology - Karakorum Mountains, Pakistan 1000 Year Tree Ring Stable Isotope Data

description: Twentieth-century warming could lead to increases in the moisture-holding capacity of the atmosphere, altering the hydrological cycle and the characteristics of precipitation. Such changes in the global rate and distribution of precipitation may have a greater direct effect on human well-being and ecosystem dynamics than changes in temperature itself. Despite the co-variability of both of these climate variables, attention in long-term climate reconstruction has mainly concentrated on temperature changes. Here we present an annually resolved oxygen isotope record from tree-rings, providing a millennial-scale reconstruction of precipitation variability in the high mountains of northern Pakistan. The climatic signal originates mainly from winter precipitation, and is robust over ecologically different sites. Centennial-scale variations reveal dry conditions at the beginning of the past millennium and through the eighteenth and early nineteenth centuries, with precipitation increasing during the late nineteenth and the twentieth centuries to yield the wettest conditions of the past 1,000 years. Comparison with other long-term precipitation reconstructions indicates a large-scale intensification of the hydrological cycle coincident with the onset of industrialization and global warming, and the unprecedented amplitude argues for a human role.
description: Oxygen and carbon stable isotope data from tree rings collected in the Karakorum Mountains, northern Pakistan, for the past century and millennium. Ring width data from these sites is also archived in the ITRDB. Presented are d13C and d18O measurements (per mil VSMOW) from five single trees at Bag-low, plus pooled isotope values. The pooled d13C values are arithmetic means, while the pooled d18O values are obtained by pooling the rings of the same trees before single-series measurements. The arithmetic mean of the five d18O series correlates at 0.85 with the pooled record, validating the d18O pooling method. Bagrot Valley B3 (bag low) Juniperus excelsa Tree Ring Site: 35°54'N, 74°56'E, 2900 m asl. Boibar Valley M1 Juniperus turkestanica Tree Ring Site: 36°37'N, 74°59'E, 3900 m asl.
IITRDB17
DOI: 10.25921/gbkh-wk82
title: NOAA/WDS Paleoclimatology - Laguna Chepical, Chile 3,000 Year Sediment Pigment and Summer Temperature

description: High-resolution reconstructions of climate variability that cover the past millennia are necessary to improve the understanding of natural and anthropogenic climate change across the globe. Although numerous records are available for the mid- and high-latitudes of the Northern Hemisphere, global assessments are still compromised by the scarcity of data from the Southern Hemisphere. This is particularly the case for the tropical and subtropical areas. In addition, high elevation sites in the South American Andes may provide insight into the vertical structure of climate change in the mid-troposphere. This study presents a 3000 yr-long austral summer (November to February) temperature reconstruction derived from the 210Pb- and 14C-dated organic sediments of Laguna Chepical (32 16' S, 70 30' W, 3050 m a.s.l.), a high-elevation glacial lake in the subtropical Andes of central Chile. Scanning reflectance spectroscopy in the visible light range provided the spectral index R570/R630, which reflects the clay mineral content in lake sediments. For the calibration period (AD 1901-2006), the R570/R630 data were regressed against monthly meteorological reanalysis data, showing that this proxy was strongly and significantly correlated with mean summer (NDJF) temperatures (R3 yr = -0.63, padj  = 0.01). This calibration model was used to make a quantitative temperature reconstruction back to 1000 BC.

The reconstruction (with a model error RMSEPboot of 0.33 C) shows that the warmest decades of the past 3000 yr occurred during the calibration period. The 19th century (end of the Little Ice Age (LIA)) was cool. The prominent warmth reconstructed for the 18th century, which was also observed in other records from this area, seems systematic for subtropical and southern South America but remains difficult to explain. Except for this warm period, the LIA was generally characterized by cool summers. Back to AD 1400, the results from this study compare remarkably well to low altitude records from the Chilean Central Valley and southern South America. However, the reconstruction from Laguna Chepical does not show a warm Medieval Climate Anomaly during the 12-13th century, which is consistent with records from tropical South America. The Chepical record also indicates substantial cooling prior to 800 BC. This coincides with well-known regional as well as global glacier advances which have been attributed to a grand solar minimum. This study thus provides insight into the climatic drivers and temperature patterns in a region for which currently very few data are available. It also shows that since ca. AD 1400, long-term temperature patterns were generally similar at low and high altitudes in central Chile.
description: Austral summer (November to February) temperature reconstruction for central Chile based on sediment pigment from Laguna Chepical
DOI: 10.25921/g318-t185
title: NOAA/WDS Paleoclimatology - REACHES Chinese Historical Climate Database

description: This paper describes the methodology of an ongoing project of constructing an East Asian climate database REACHES based on Chinese historical documents. The record source is Compendium of Meteorological Records of China in the Last 3000 Years which collects meteorology and climate related records from mainly official and local chronicles along with a small number of other documents. We report the digitization of the records covering the period 1644–1795. An example of the original records is translated to illustrate the typical contents which contain time, location and type of events. Chinese historical times and location names are converted into Gregorian calendar and latitudes and longitudes. A hierarchical database system is developed that consists of the hierarchies of domains, main categories, subcategories, and further details. Historical events are then digitized and categorized into such a system. Code systems are developed at all levels such that the original descriptive entries are converted into digitized records suitable for treatment by computers. Statistics and characteristics of the digitized records in the database are described.
description: This database mainly digitizes weather records quoted in 'A Compendium of Chinese Meteorological Records in the Last 3,000 Years' (Zhang, ed., 2nd Edition 2013) that contains a huge number of original records collected from 7,930 official documents, local chronicles, and private notes.
DOI: 10.25921/grqz-1n91
title: NOAA/WDS Paleoclimatology - Labrador Sea 645 Year Coralline Algae Time Series

description: North Atlantic sea surface temperatures experience variability with a periodicity of 60-80 years that is known as the Atlantic Multidecadal Oscillation (AMO). It has a profound imprint on the global climate system that results in a number of high value societal impacts. However the industrial period, i.e. the middle of the 19th century onwards, contains only two full cycles of the AMO making it difficult to fully characterize this oscillation and its impact on the climate system. As a result, there is a clear need to identify paleoclimate records extending into the pre-industrial period that contain an expression of the AMO. This is especially true for extratropical marine paleoclimate proxies where such expressions are currently unavailable. Here we present an annually resolved coralline algal time series from the northwest Atlantic Ocean that exhibits multidecadal variability extending back six centuries. The time series contains a statistically significant trend towards higher values, i.e. warmer conditions, beginning in the 19th century that coincided with an increase in the time series' multidecadal power. We argue that these changes are associated with a regional climate reorganization involving an amplification of the AMO that coincided with onset of the industrial-era warming.