cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.25921/f5ph-ax07
title: NOAA/WDS Paleoclimatology - Subpolar North Atlantic 4500 Year Alkenone SST Reconstructions

description: Marine paleo-records acquired at high temporal resolution provide critical data for testing numerical climate models and help to understand processes underlying ocean variability. This study presents a unique 4500-year reconstruction of sea surface temperature (SST) obtained from alkenones in the North Atlantic Polar Front area off North Iceland, at an average temporal resolution of 4-5 years. Spectral analysis of this signal shows dominant multidecadal oscillations which occurred with a stronger amplitude between 2500 and 4200 years BP, hand in hand with fluctuations of bottom currents indicated by paleomagnetic proxies. Contemporaneous large excursions of the Inter-tropical Convergence Zone (ITCZ) are also recorded by the distant Cariaco titanium time series, suggesting a link with low latitude Atlantic climate. We speculate that the oscillations reflect changes of the Meridional Overturning Circulation (MOC) induced by increased ENSO activity.
description: A 4500 year long reconstruction of sea surface temperature (SST) obtained from alkenone paleothermometry from the MD99-2275 site, North of Iceland. This record combines data from Sicre et al., QSR 2008 and Sicre et al., Paleoceanography 2011. The latter extend the record to the most recent part of the record that was missing in the 2008 data set. Overall, this spliced record combines three sediment sequence reconstructions with different coring devices (piston, gravity and box) in a highly variable region thus represents a unique regional reconstruction benchmark.  

MD99-2275:  66°33'N, 17°42'W, 470 m water depth
DOI: 10.25921/f9fe-hb07
title: NOAA/WDS Paleoclimatology - Cueva del Tigre Perdido, Peru Stalagmite Fluid Inclusion Isotope Data

description: Most proxy records used for reconstruction of Holocene climate of Amazonia are unable to quantitatively distinguish between the effect of temperature and rainfall amounts.  We present a new isotope technique applied to a ~13,500 yr stalagmite archive from Peruvian Amazonia. By analysing the coupled isotope composition of fossil dripwater trapped in stalagmite fluid inclusions, and that of the calcite hosting the fluid inclusions, we were able to calculate independent paleotemperatures and rainfall amounts.This stalagmite record shows that Holocene climate variation was controlled by orbitally-forced Southward migration of the Inter Tropical Convergence Zone. While temperature remained constant, isotope variation of rainwater, reflected in fluid inclusion water d18O composition, suggests a ~15-30% increase in convective rainfall through the Holocene.  A comparison of the low-land Peruvian fluid inclusion record with the high Andean Huascaran ice core record shows a constant ~12‰ offset of d18O curves for the Holocene, suggesting that Andean vertical temperature gradients (lapse rates) did not vary much over the last 9000 years. During the Younger Dryas interval, however, the offset of d18O values was much higher than in the Holocene. This may be attributed to a relative drop in air temperatures in the highlands (higher lapse rate), caused by long distance teleconnections to climate perturbations in the North Atlantic.  In a wider perspective, fluid inclusion isotope analysis drastically improves paleotemperature reconstructions based on speleothem calcite d18O data, because it provides the d18O value of drip water through time, which is usually the most important unknown in paleotemperature equations.
description: Stalagmite fluid inclusion and calcite oxygen isotope record from an Amazon Basin cave, dated by U-Th.  Data consist of fluid inclusion d18O and dH2 and calcite d18O data from two stalagmites collected in Cueva del Tigre Perdido, Nueva Cajamarca, San Martín, Peru: 5°56'26"S, 77°18'29"W. UPDATE 3/2025: sample depths from the SISAL Global Speleothem Isotope Database v2 (https://doi.org/10.25921/s4ze-ve52) were added to data tables for cores NC-A and NC-B.
DOI: 10.25921/f3b8-8e77
title: NOAA/WDS Paleoclimatology - Mundo - Caviahue SA - ARAR - ITRDB ARGE114

description: Seventeen tree-ring chronologies from the conifer Araucaria araucana (Molina) K. Koch have been analyzed across its range of distribution in Argentina. We studied the growth patterns and determined the main climatic factors influencing A. araucana radial growth. All the chronologies show a strong common signal observed by the high amount of variance explained by the first principal component (PC1) and the high mean correlation (r = 0.597) between the chronologies over the 1676-1974 interval. On this basis, we developed a regional chronology that is 866 years long (A.D. 1140-2006) and includes 621 tree-ring series. Based on the PC2 scores, chronologies were clearly separated by elevation in high- and low-elevation records. Regional tree growth is strongly negatively related to temperatures during summer and fall in the previous-growing season and spring in the current-growing season, respectively. A positive association of tree growth with precipitation is recorded during spring in the current growing season. These results suggest a close relationship between A. araucana tree growth and water availability on a regional scale. This observation is also consistent with a positive and significant correlation between our A. araucana regional record and a reconstruction of November-December rainfall for northern Patagonia inferred from the xeric Austrocedrus chilensis during the past 400 years. Negative correlations between A. araucana regional growth and the sea surface temperature in the Nino 3.4 region reflect the occurrence of above-mean summer temperatures in the region during positive tropical Pacific SST anomalies. The negative relationship with the Antarctic Oscillation (AAO) results from reduced precipitation in our study region during the positive phase of the AAO. The effect of elevation on water availability is consistent with significant correlations between ring-width variations at lower elevations and the Palmer Drought Severity Index during spring and summer in the current growing season. Our study emphasizes the high dendroclimatological potential of A. araucana chronologies for reconstructing past climate variations in northern Patagonia during the past millennium.
description: NOAA Template Chronology file added 2018-12-13. NOAA Template Raw Measurements file added 2019-04-29.
DOI: 10.25921/f9c6-vh66
title: NOAA/WDS Paleoclimatology - D'Arrigo - Manitoba Composite - PCGL - ITRDB CANA324

description: Previous tree-ring-based Northern Hemisphere temperature reconstructions portray a varying amplitude range between the "Medieval Warm Period" (MWP), "Little Ice Age" (LIA) and present. We describe a new reconstruction, developed using largely different methodologies and additional new data compared to previous efforts. Unlike earlier studies, we quantify differences between more traditional (STD) and Regional Curve Standardization (RCS) methodologies, concluding that RCS is superior for retention of low-frequency trends. Continental North American versus Eurasian RCS series developed prior to merging to the hemispheric scale cohere surprisingly well, suggesting common forcing, although there are notable deviations (e.g., fifteenth to sixteenth century). Results indicate clear MWP (warm), LIA (cool), and recent (warm) episodes. Direct interpretation of the RCS reconstruction suggests that MWP temperatures were nearly 0.7C cooler than in the late twentieth century, with an amplitude difference of 1.14C from the coldest (1600-1609) to warmest (1937-1946) decades. However, we advise caution with this analysis. Although we conclude, as found elsewhere, that recent warming has been substantial relative to natural fluctuations of the past millennium, we also note that owing to the spatially heterogeneous nature of the MWP, and its different timing within different regions, present palaeoclimatic methodologies will likely "flatten out" estimates for this period relative to twentieth century warming, which expresses a more homogenous global "fingerprint." Therefore we stress that presently available paleoclimatic reconstructions are inadequate for making specific inferences, at hemispheric scales, about MWP warmth relative to the present anthropogenic period and that such comparisons can only still be made at the local/regional scale.
description: NOAA Template Raw Measurements file added 2019-01-27. NOAA Template Raw Measurements file added 2019-02-04. 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/fj4f-my05
title: NOAA/WDS Paleoclimatology - Heshang Cave, China 8.2ka Subannual Stalagmite Stable Isotope Data

description: An abrupt cooling event in the North Atlantic region 8,200 years ago affected climate throughout the Northern Hemisphere. The event is well constrained in Greenland ice cores, but lack of resolution in records from other regions has challenged our understanding of the timing and nature of the associated teleconnections. Speleothem records from East Asia have suggested monsoonal changes associated with the 8,200 year event, but the nature of these changes remains controversial. Here we assess changes in East Asian precipitation during the event from a sub-annually resolved stalagmite record from central China. Using d18O and Mg/Ca measurements of the speleothem carbonate, we show that climate dried significantly about 8,200 years ago. Based on our annual-layer-counted chronology, we show that the dry event lasted 150 years, with a central period of pronounced aridity that lasted 70 years. The duration and evolution of the event is indistinguishable from that observed in the Greenland ice cores. We therefore conclude that an effective and rapid atmospheric teleconnection exists between the North Atlantic and the monsoon system in warm climates similar to today's.
description: The dataset is a sub-annual resolution d18O and d13C record for the 8.2kyr event from Heshang cave in the Yangtze Valley in central China. Stable isotope samples were micro-milled continuously at ~40 um intervals from 235.3 cm to 231.9 cm of HS-4 with an average resolution of ~0.3 years. A total of 869 samples were measured on a Thermo Delta V Advantage Isotope Ratio Mass spectrometer fitted with a Kiel Carbonate Device IV at Oxford Department of Earth Sciences, with a precision of ±0.08 per mil. The chronology of stalagmite HS-4 during 8.2 kyr event has been established independently by U-Th dating (9 samples measured by MC-ICP-MS at Oxford University) and layer counting. Full details of the chronology and age model are provided in Supplementary Information of Liu et al. 2013.
DOI: 10.25921/fx10-df76
title: NOAA/WDS Paleoclimatology - Nerfloen Norway 7800 Year Lake Sediment Data

description: We explore the possibility of building a continuous glacier reconstruction by analyzing the integrated sedimentary response of a large (440 km2) glacierized catchment in western Norway, as recorded in the downstream lake Nerfloen (N61°56', E6°52'). A multi-proxy numerical analysis demonstrates that it is possible to distinguish a glacier component in the ~8000-yr-long record, based on distinct changes in grain size, geochemistry, and magnetic composition. Principal Component Analysis (PCA) reveals a strong common signal in the 15 investigated sedimentary parameters, with the first principal component explaining 77% of the total variability. This signal is interpreted to reflect glacier activity in the upstream catchment, an interpretation that is independently tested through a mineral magnetic provenance analysis of catchment samples.  Minimum glacier input is indicated between 6700-5700 cal yr BP, probably reflecting a situation when most glaciers in the catchment had melted away, whereas the highest glacier activity is observed around 600 and 200 cal yr BP. During the local Neoglacial interval (~4200 cal yr BP until present), five individual periods of significantly reduced glacier extent are identified at ~3400, 3000-2700, 2100-2000, 1700-1500, and ~900 cal yr BP.
description: This file contains the data plotted in figure 8 in Vasskog et al. 2012. This includes the first principal component (1st PC) of 15 lake sediment parameters, and the ratio between bulk magnetic susceptibility measured at 77K and 293K, plotted against a 4th degree polynomial age-depth model. Principal Component Analysis (PCA) is employed to detect patterns of variability that are shared between the investigated lake sediment variables. The PCA includes primary count rates of Fe, Rb, Mn, Sr, Zr, and the K/Ti ratio, six grain-size classes as compositional percentages, and physical sediment variables LOI, DBD, and XBulk, resulting in a final data set containing 15 different variables, with a stratigraphical resolution of one centimeter. The first PCA explains 77% of the total variability of the data set. Sections interpreted as rapid depositional events (e.g. flood and avalanche deposits) have been removed from this data set. The physical parameters (LOI, DBD and magnetism) were, however, plotted prior to removal of these 'event layers' in figure 3 of the paper. The methodology used for detecting event layers is described in the supplementary material of the paper. Nerfloen, western Norway: 61°56'N, 6°52'E, 29m elevation, 18m depth.
DOI: 10.25921/fy98-ft36
title: NOAA/WDS Paleoclimatology - North Atlantic SST, Foraminifera, Isotope and Ice-Rafted Debris Data during the last interglacial and glacial

description: A period of continental ice growth between about 80,000 and 70,000 years ago was controlled by a decrease in summer insolation, and was among the four largest ice expansions of the past 250,000 years. The moisture source for this ice sheet expansion, known as the Marine Isotope Stage (MIS) 5a/4 transition, has been proposed to be the warm subpolar and northern subtropical Atlantic Ocean. However, the mechanism by which glaciers kept growing through three suborbital cooling events within this period, which were associated with iceberg discharge in the North Atlantic and cooling over Greenland, is unclear. Here we reconstruct parallel records of sea surface and air temperatures from marine microfossil and pollen data, respectively, from two sediment cores collected within the northern subtropical gyre. The thermal gradient between the cold air and warmer sea increased throughout the MIS5a/4 transition, and was marked by three intervals of even more pronounced thermal gradients associated with the C20, C19 and C18’ cold events. We argue that the warm ocean surface along the western European margin provided a source of moisture that was transported, through northward-tracking storms, to feed ice sheets in colder Greenland, northern Europe and the Arctic.
description: Data table in file sanchezgoni2013-md95-2042-npachy.txt was updated on 17-Jun-2021 to correct n.pachy-l% data column.
DOI: 10.25921/fk8m-d446
title: NOAA/WDS Paleoclimatology - Hongyuan, Tibetan Plateau Holocene Peat Data

description: The variations of summer and winter monsoons during the Holocene in the eastern Tibetan Plateau are shown to follow two basic models based on the reliable dating and high-resolution monsoon proxies determinations, one being a synchronous model in that both summer and winter monsoons are strengthening or decreasing, and the other to form a complementary pattern. These two different patterns evenly interact with each other on different time scales and together compose a complicated monsoon climatic model in this region. The climatic condition integrated by winter and summer monsoons is synchronous to the global pattern, which also shows the instability of the Holocene climate on centennial- millennial timescale. The abrupt monsoon event in about 6.2 ka cal. BP is much more severe than that in ca. 8.0 ka cal. BP, which indicates the regional character of the Asian monsoon and that the Asian monsoon climate is indeed a window on the global climate system.
description: Greyscale, Ash Content, and Humification data from a peat core collected at Hongyuan, northeastern Tibetan Plateau, providing Holocene paleomonsoon proxies. 

Hongyuan peat core: 32°46.7'N, 102°31'E, 3527 m asl, 6.5 m core length.
DOI: 10.25921/faaf-j173
title: NOAA/WDS Paleoclimatology - Sauchyn - Lake Metigoshe - QUMA - ITRDB ND017

description: Tree ring data from the International Tree Ring Data Bank and World Data Center for Paleoclimatology archives.  Most data sets include raw treering measurements (most are annual ring width, with some collections of earlywood or latewood width or wood density), plus chronologies (standardized growth indices for a site compiled from multiple treering samples). Reconstructions of climate variables are included with some of these data sets.  Each data type is stored in a separate data file; the data type is coded into the file name. For details please see: http://www.ncdc.noaa.gov/paleo/treeinfo.htmll
description: NOAA Template Raw Measurements file added 2020-01-15.
DOI: 10.25921/fwk2-sk63
title: NOAA/WDS Paleoclimatology - Lloyd - Zhigansk floodplain - PCOB - ITRDB RUSS207

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: Site was outside the town of Zhigansk, on the floodplain 
# of a tributary to the Lena River.  There is some human 
# disturbance (in the form of cut stumps) near the site.  
# This file contains all of the measured trees.  Trees have 
# been crossdated, but some cores contain persistent problems 
# that were not resolved.  We advise users to examine COFECHA 
# output prior to use-- for climatological studies, users will 
# probably want to eliminate a few cores with persistent problems. NOAA Template Raw Measurements file added 2019-04-08. 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/f0cx-w628
title: NOAA/WDS Paleoclimatology - Gavin - Bolton Mountain High - PCRU - ITRDB VT006

description: Tree ring data from the International Tree Ring Data Bank and World Data Center for Paleoclimatology archives.  Most data sets include raw treering measurements (most are annual ring width, with some collections of earlywood or latewood width or wood density), plus chronologies (standardized growth indices for a site compiled from multiple treering samples). Reconstructions of climate variables are included with some of these data sets.  Each data type is stored in a separate data file; the data type is coded into the file name. For details please see: http://www.ncdc.noaa.gov/paleo/treeinfo.htmll
description: NOAA Template Raw Measurements file added 2019-02-08.
DOI: 10.25921/f56j-kr72
title: NOAA/WDS Paleoclimatology - Xinya Cave, China Glacial Speleothem Oxygen Isotope Data

description: A 26-cm-long stalagmite (XY2) from Xinya Cave in northeastern Chongqing of China has been ICP-MS 230Th/U dated, showing a depositional hiatus at 2.3 cm depth from the top. The growth of the 2.3-26 cm interval determined by four dates was between 57 ka and 70 ka, with a linear growth rate of 0.023 mm/a.  We have analyzed 190 samples for d18O and d13C, mostly in the 2.3-26 cm part. The d18O and d13C values between 57 ka and 70 ka reveal decadal-to-centennial climatic variability during the glacial interval of Marine Isotope Stage 4 (MIS4), exhibiting much higher resolution than that of the published Hulu and Dongge records during this interval. Speleothem d18O in eastern China, including our study area can be used as a proxy of summer monsoon strength, with lighter values pointing to stronger summer monsoon and higher precipitation, and vice versa. Two decreases in the d18O signature of XY2 record around 59.5 and 64.5 Ka are argued to correspond to the Dansgaard-Oeschger (D-O) events 17 and 18 respectively. The Heinrich event 6 (H6) can be identified in the record as a heavy d18O peak around 60 ka, indicating significant weakening of the monsoon in Chongqing during the cold period.The XY2 d18O record shows very rapid change toward to the interstadial condition of the D-O event, but more gradual change toward to the cold stadial condition. This phenomenon found in the Greenland ice core records is rarely observed so clearly in previously published speleothem records. According to SPECMAP d18O record, the glacial maximum of MIS 4 was around 64.5 ka with the boundary of MIS 3/4 around 60 ka. Unlike the marine record, the speleothem record of XY2, China, exhibits much high frequency variations without an apparent glacial maximum during MIS 4. However, the timing of MIS 3/4 boundary seems to be around 60 ka when the H6 terminated, in agreement with the marine chronology.  The growth period of sample XY2 during glacial times probably reflects a local karstic routing of water, rather than having climatic significance.
description: Speleothem oxygen isotope data from a 26-cm-long stalagmite (XY2) 
from Xinya Cave in south China.  Stalagmite XY2 is ICP-MS 230Th/U 
dated to between 57 ka and 70 ka. The d18O values reveal decadal-
to-centennial climatic variability during the glacial interval of 
Marine Isotope Stage 4 (MIS4). Heinrich event 6, and Dansgaard-
Oeschger (D-O) events 17 and 18 can be determined by the XY2 d18O 
records, which are higher resolution than previous records in China.
DOI: 10.25921/fbsf-cf41
title: NOAA/WDS Paleoclimatology - Lake Logung, Indonesia 1400 Year Multiproxy Sediment Data

description: Variations in the location and strength of convection in the Western Pacific Warm Pool (WPWP) have a profound impact on the distribution and amount of global rainfall. Much of the variability in WPWP convection is attributed to variations in the El Niño-Southern Oscillation, for which the long-term trends and forcing mechanisms remain poorly understood. Despite the importance of WPWP convection to global climate change, we have very few paleohydrological reconstructions from the region. Here we present a new paleolimnologic and paleohydrologic record spanning the past 1,400 years using a multi-proxy dataset from Lake Logung, located in East Java, Indonesia that provides insights into centennial-scale trends in warm pool hydrology. Organic matter d13C data indicate that East Java became wetter over the last millennium until ca. 1800 Common Era (CE), consistent with evidence for the southward migration of the Intertropical Convergence Zone (ITCZ) during this time. Superimposed on this long-term trend are four decade- to century-scale droughts, inferred from organic matter d13C and calcite abundance data. They are centered at 1030, 1550, 1830, and 1996 CE. The three more recent droughts correlate with hydrologic anomalies documented in other proxy records from the WPWP region on both sides of the equator, and the two most recent droughts correlate in time with historically documented periods of multiple, intense El Niño events. Thus, our record provides strong evidence that century-scale hydrologic variability in this region relates to changes in the Walker Circulation. Human activity within the lake catchment is apparent since 1860 CE.
description: Multiproxy sediment data from Lake Logung, Indonesia, for the past 1400 years. 
Paleoenvironmental proxies measured include Magnetic Susceptibility, Organic 
and Inorganic Carbon , Total N, C:N ratio, C and N isotopes, and Biogenic Opal. 

Lake Logung, Indonesia: 8°2.509'S, 113°18.452'E, 215m elevation, 7m water depth.