cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.25921/zpqc-w669
title: NOAA/WDS Paleoclimatology - Lake Victoria, East Africa 15KYr TEX86 and Leaf Wax dD and d13C Data

description: New molecular proxies of temperature and hydrology are helping to constrain tropical climate change and elucidate possible forcing mechanisms during the Holocene. Here, we examine a ~14,000 year record of climate variability from Lake Victoria, East Africa, the world's second largest freshwater lake by surface area. We determined variations in local hydroclimate using compound specific dD of terrestrial leaf waxes, and compared these results to a new record of temperature utilizing the TEX86 paleotemperature proxy, based on aquatic Thaumarchaeotal membrane lipids. In order to assess the impact of changing climate on the terrestrial environment, we generated a record of compound specific d13C from terrestrial leaf waxes, a proxy for ecosystem-level C3/C4 plant abundances, and compared the results to previously published pollen-inferred regional vegetation shifts. We observe a general coherence between temperature and rainfall, with a warm, wet interval peaking ~10-9 ka and subsequent gradual cooling and drying over the remainder of the Holocene. These results, particularly those of rainfall, are in general agreement with other tropical African climate records, indicating a somewhat consistent view of climate over a wide region of tropical East Africa. The d13C record from Lake Victoria leaf waxes does not appear to reflect changes in regional climate or vegetation. However, palynological analyses document an abrupt shift from a Poaceae (grasses)-dominated ecosystem during the cooler, arid late Pleistocene to a Moraceae-dominated (trees/shrubs) landscape during the warm, wet early Holocene. We theorize that these proxies are reflecting vegetation in different locations around Lake Victoria. Our results suggest a predominantly insolation-forced climate, with warm, wet conditions peaking at the maximum interhemispheric seasonal insolation contrast, likely intensifying monsoonal precipitation, while maximum aridity coincides with the rainy season insolation and the interhemispheric contrast gradient minima. We interpret a shift in conditions at the Younger Dryas to indicate a limited switch in insolation-dominated control on climate of the Lake Victoria region, to remote teleconnections with the coupled Atlantic and Pacific climate system.
description: This dataset includes TEX86, dD of leaf wax n-alkanoic acids (C28 chain length), and d13C of n-alkane (C29 chain length). TEX86 data includes TEX86 value and calibrated temperature (using Kim et al., 2010 as described in the text). This dataset also includes BIT Index determined. dD dataset includes the leaf wax n-alkanoic value (mean of multiple measurements, with standard deviation indicated). Ice volume correction column described in text. d13C n-alkane data was based on C29 chain length (most abundant, best chromatography). Standard deviation of replicates shown, as well as estimated C4 plant percentage (and 1 standard deviation from this estimation) as described in text and shown in figures.
DOI: 10.25921/za87-1m22
title: NOAA/WDS Paleoclimatology - Fonti - Novaggio - CASA - ITRDB SWIT305

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: 
# # # Collection purpose: 
# # # Earlywood vessel size chronology and climate-growth relationships
# # # 
# # # 
# # # 
# # # Cores are stored at: 
# # # 
# # # 
# # # 
# # # Notes: 
# # # Formerly Novaggio 
# # # 
# # # 
# # # References:
# # # Fonti and Garcia Gonzalez 2004, New Phytologist;
# # # Garcia Gonzalez and Fonti 2006, Tree Physiology  NOAA Template Raw Measurements file added 2019-02-05.
DOI: 10.25921/zja5-6f39
title: NOAA/WDS Paleoclimatology - Cherubini - Vordemwald - ABAL - ITRDB SWIT358

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: Cores are stored at: 
# WSL
# 
# Notes: 
# NNW exposure
# Formerly vor_628_ABAL_R.tuc NOAA Template Raw Measurements file added 2019-02-05.
DOI: 10.25921/zajp-w062
title: NOAA/WDS Paleoclimatology - Northern European 2000 Year Summer Temperature Reconstruction

description: Tree-ring chronologies of maximum latewood density are most suitable to reconstruct annually resolved summer temperature variations of the late Holocene. The two longest such chronologies have been developed in northern Europe stretching back to the 2nd century BC, and the 5th century AD. We show where similarities between the two chronologies exist, and combine portions of both into a new summer temperature reconstruction for the Common Era. To minimize the transfer of potential biases, we assess the contribution of the candidate reconstructions' measurements, and exclude data (i) from exceptionally young and old trees, and (ii) produced by different laboratory technologies. Our new composite reconstruction reveals warmer conditions during Roman, Medieval and recent times, separated by prolonged cooling during the Migration period and Little Ice Age. Twentieth century warmth, as indicated in one of the existing density records, is reduced in the new reconstruction, also affecting the overall, millennial-scale, cooling trend over the late Holocene (-0.30C per 1000 years). Due to the reduced biological memory, typical for tree-ring density measurements, the new reconstruction is most suitable for evaluating the rate and speed of abrupt summer cooling following large volcanic eruptions.
description: Summer temperature reconstruction based on integrated tree-ring maximum density (MXD) data sets of Nscan (Esper et al. 2012) and Torneträsk (Schweingruber et al. 1988)
DOI: 10.25921/zrq3-1h73
title: NOAA/WDS Paleoclimatology - Luckman - Peyto Glacier - PCEN - ITRDB CANA444

description: A new network of 21 Picea engelmannii Parry ex Engelm. ring-width chronologies was developed from tree-line sites in the Canadian Rockies. These chronologies range in length from 297 to 648 years (mean 423 years) and have mean sensitivities between 0.16 and 0.20 (mean 0.18), first-order autocorrelations between 0.73 and 0.88 (mean 0.83), and subsample signal strengths >0.85 for 246-494 years (mean 324 years). Mean intersite correlations (A.D. 1700-1982) for chronologies with expressed population signals >0.85 are 0.46 and 0.63 for standard and residual chronologies, respectively. Standard ring-width chronologies are, in general, positively correlated with summer temperatures and negatively correlated with spring and previous summer temperatures. A regional June-September temperature reconstruction for the Banff-Jasper region (BJR; A.D. 1715-1982) was developed using multiple regression of three significant principal components from 14 standard ring-width chronologies. The first principal component contains 55% of the total chronology variance. The model reconstructs 38% of summer temperature variance during the calibration period (1888-1982). The BJR is the first regional temperature reconstruction for this area based on ring-width data from a network of sites. The reconstructed temperature patterns are broadly similar to other regional estimates of past temperatures. Above-average summer temperatures occurred in the mid-20th century and the late 1700s - early 1800s. Most of the 19th century was unusually cold, with the coldest conditions in the late 19th century. Detailed differences between BJR and previously developed reconstructions lie well within 2 sigma confidence limits and may reflect differences in tree species, modelling techniques, spatial coverage, and the seasonal temperature parameter reconstructed.
description: Cores are stored at:
# # University of Western Ontario
# # 
# # Detrending:
# # -ve exponential or linear with -ve or 0 slope
# # 
# # References:
# # Reynolds, J.  1992.  
# # Dendrochronology and glacier fluctuations at Peyto Glacier, Banff National Park.  
# # Unpublished B.Sc. thesis, Department of Geography, University of Western Ontario NOAA Template Raw Measurements file added 2019-01-27. NOAA Template Raw Measurements file added 2019-02-04.
DOI: 10.25921/zf5k-t724
title: NOAA/WDS Paleoclimatology - Lara - Lenga abajo - NOPU - ITRDB CHIL021

description: Nothofagus pumilio (Poepp et Endl.) Krasser, is a deciduous tree species that grows in Chile and adjacent Argentina between 36 and 56°S, often forming the Andean tree line. This paper presents the first eight tree-ring chronologies from N. pumilio at its northern range limit in the central Andes of Chile (36-39°S) and the first precipitation reconstruction for this region. Samples were taken from upper tree-line stands (1500-1700 m elevation) in three study areas: Vilches, Laguna del Laja, and Conguillío. Results indicate that, at the northern sites (Vilches and Laguna del Laja), the tree-ring growth of N. pumilio is positively correlated with late-spring and early summer precipitation and that higher temperatures reduce radial growth, probably because of an increase in evapotranspiration and decrease in water availability. At the southern Conguillío study area, radial growth was negatively correlated with late-spring and early summer precipitation. The presence of volcanic activity in this latter study area, which might have masked the climate signal, did not seem to have a significant influence on radial growth. A reconstruction of November-December (summer) precipitation for the period 1837-1996 from N. pumilio tree-ring chronologies accounted for 37% of instrumentally recorded precipitation variance. This is the first precipitation reconstruction from N. pumilio chronologies. Only temperature and snow cover have previously been reconstructed using this species. The reconstruction indicates that the driest and wettest 25-year periods within the past 160 years are 1890-1914 and 1917-1941, respectively.
description: Purpose of Collection:
# Climatology
# 
# Cores are stored at:
# University of Western Ontario NOAA Template Raw Measurements file added 2019-04-29.
DOI: 10.25921/z0rz-9c23
title: NOAA/WDS Paleoclimatology - Cherubini - Marina di Bibbona - PIPN - ITRDB ITAL030

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: Collection purpose: 
# Impact on sea erosion on coastal forests
# 
# Cores are stored at: 
# 
# Notes: 
# Cecina, 5 km south
# Four plots were located at a distance from current seashore position of 80, 155, 245 and 320 m
# Formerly mb_interior
# 
# References:
# Raddi et al (2009): 
# The impact of sea erosion on oastal Pinus pinea stands: 
# A diachronic analysis combining tree-rings and ecological markers, 
# FEaM 527, 773-781.  NOAA Template Raw Measurements file added 2019-02-05.
DOI: 10.25921/zmr5-vf04
title: NOAA/WDS Paleoclimatology - Paritsis - Cerro Colorado 2 - NOPU - ITRDB ARGE125

description: In the temperate forests of the southern Andes, Nothofagus pumilio, the dominant species of the most extensive forest type, experiences severe defoliation caused by caterpillars of the Ormiscodes genus (Lepidoptera: Saturniidae). This study uses tree rings to reconstruct the history of Ormiscodes outbreaks for the 1850-2005 period and examines relationships between outbreaks and climate variability. We used local climate records to compare outbreak-climate relationships in the northern Patagonian Andes (c. 41°S) and the cooler southern Patagonian Andes (c. 49°S). We also examined relationships between outbreak events and regional climate variability driven by variability in the Southern Annular Mode (SAM) and the El Niño-Southern Oscillation. Although relationships between Ormiscodes outbreaks and climate proved to be complex, in northern Patagonia defoliation events are associated with drier and warmer than average growing seasons. Warming and drying trends in Patagonia during the latter part of the 20th century have been linked to a positive trend in SAM. During the post-1976 period of accelerated warming in Patagonia, widespread defoliation outbreaks have occurred in both northern and southern Patagonia but the increase in frequency of events has been greater in the south. In southern Patagonia the increases in frequency of outbreaks in the late 20th century appear to be unprecedented over the c. 150 year tree-ring record of reconstructed outbreaks. These results are consistent with the greater magnitude of recent warming in southern Patagonia, and suggest that under predicted warmer and drier climates in the 21st century, defoliator outbreaks may continue to increase in frequency. This study is the first systematic reconstruction of past insect outbreaks in South America and provides a preliminary understanding of how climate variability affects defoliator outbreaks in Patagonian Nothofagus forests.
description: Purpose of Collection:
# Ecology - insect outbreaks
# 
# Cores are stored at:
# Biogeography Lab, Geography Department, University of Colorado at Boulder
# 
# Notes:
# Most tree ring samples were collected during the growing season, so the most recent ring 
# is not a complete ring. The most recent ring was therefore not used in the analysis by 
# Paritsis and Veblen (2011). NOAA Template Raw Measurements file added 2019-04-29.
DOI: 10.25921/zwn2-q031
title: NOAA/WDS Paleoclimatology - Luckman - Bow Summit/Peyto Lake - PCEN - ITRDB CANA434

description: We present a significant update to a millennial summer temperature reconstruction (1073-1983) that was originally published in 1997. Utilising new tree-ring data (predominantly Picea engelmannii), the reconstruction is not only better replicated, but has been extended (950-1994) and is now more regionally representative. Calibration and verification statistics were improved, with the new model explaining 53% of May-August maximum temperature variation compared to the original (39% of April-August mean temperatures). The maximum latewood density data, which are weighted more strongly in the regression model than ringwidth, were processed using regional curve standardisation to capture potential centennial to millennial scale variability. The reconstruction shows warm intervals, comparable to twentieth century values, for the first half of the eleventh century, the late 1300s and early 1400s. The bulk of the record, however, is below the 1901-1980 normals, with prolonged cool periods from 1200 to 1350 and from 1450 to the late 19th century. The most extreme cool period is observed to be in the 1690s. These reconstructed cool periods compare well with known regional records of glacier advances between 1150 and the 1300s, possibly in the early 1500s, early 1700s and 1800s. Evidence is also presented of the influence of solar activity and volcanic events on summer temperature in the Canadian Rockies over the last 1,000 years. Although this reconstruction is regional in scope, it compares well at multi-decadal to centennial scales with Northern Hemisphere temperature proxies and at millennial scales with reconstructions that were also processed to capture longer timescale variability. This coherence suggests that this series is globally important for the assessment of natural temperature variability over the last 1,000 years.
description: NOAA Template Raw Measurements file added 2019-02-04.
DOI: 10.25921/zkr6-p676
title: NOAA/WDS Paleoclimatology - Hughes and Graumlich 1996 Multi-Millennial Nevada Precipitation Reconstruction

description: Multimillennial tree-ring chronologies from the mountains of the western United States provide an excellent opportunity to study decade to century scale variability in pre-instrumental times. This results from the lack of ecological interaction between the widely-spaced, climate-sensitive, long-lived trees characteristic of the higher elevations of this region. The availability of climate-sensitive > 1000 year tree-ring records in the western conterminous United States is unique. For example, 80 tree-ring chronologies of at least 1000 years length and 23 of at least 2000 years length, have been developed at our Laboratory for this region. A number of climate reconstructions of high quality have already been published using subsets of these data. The great potential of this resource will be demonstrated by reference to these reconstructions. In particular, we introduce a preliminary reconstruction of precipitation in the Great Basin covering the period 6000 B.C. to A.D. 1979. We will use this to place in context a striking pattern of two multidecade droughts each terminated by intense wet periods in the period between A.D. 900 and 1400.
description: Reconstructed precipitation for Nevada Climate Division 3, annual July through June. Trees used for the reconstruction are bristlecone pine from Methuselah Walk, White Mountains, California. These data are archived with the ITRDB, filenames CA535.crn (standardized chronology) and CA535.rwl (ringwidth measurements)
DOI: 10.25921/zrdm-qv69
title: NOAA/WDS Paleoclimatology - Norwegian Sea Diatom SST Reconstruction for the last 2,000 Years

description: A high-resolution sediment core from the Vøring Plateau has been studied to document the centennial to millennial variability of the surface water conditions during the Holocene Climate Optimum (HCO) and the late Holocene period (LHP) in order to evaluate the effects of solar insolation on surface ocean climatology. Quantitative August summer sea surface temperatures (SSSTs) with a time resolution of 2–40 years are reconstructed by using three different diatom transfer function methods. Spectral- and scale-space methods are applied to the records to explore the variability present in the time series at different time scales. The SSST development in core MD95-2011 shows a delayed response to Northern Hemisphere maximum summer insolation at ca. 11,000 years B.P. The record shows the maximum SSST of the HCO to be from 7.3 to 8.9 kyr B.P., which implies that the site was located in the regional warm water pool removed from the oceanic fronts and Arctic waters. Superimposed on the general cooling trendare higher-frequency variabilities at time scales of 80–120, 210–320, 320–640, and 640–1280 years. The climate variations at the time scale of 320–640 years are documented both for periods of high and low solar orbital insolation. We found evidence that the submillennial-scale mode of variability (640–900 years) in SSST evident during the LHP is directly associated with varying solar forcing. At the shorter scale of 260–450 years, the SSST during the LHP displays a lagged response to solar forcing with a phase-locked behavior indicating the existence of a feedback mechanism in the climate system triggered by variations in the solar constant as well as the role of the thermal inertia of the ocean. The abruptness of the cooling events in the LHP, especially pronounced during the onsets of the Holocene Cold Period I (approximately 2300 years B.P.) and the Little Ice Age (approximately 550 years B.P.), can be explained by a shutdown of deep convection in the Nordic Seas in response to negative solar insolation anomalies. These cooling events are on the order of 1.5°C.
description: A 2000-year-long diatom inferred August sea surface temperature reconstruction, with 2-13 year resolution, from marine sediment core CR 948/2011 from the Vøring Plateau, Norwegian Sea. The composite core CR 948/2011 consists of the calypso core MD95-2011 and the boxcore JM97-948/2A. A modern training set consisting of 139 surface samples with 52 diatom species from the Nordic Seas and the North Atlantic was utilized to convert downcore diatom counts to quantitative August SST using the weighted averaging partial least squares (WA-PLS) transfer function method.
DOI: 10.25921/z73y-mx49
title: NOAA/WDS Paleoclimatology - Lake El’gygytgyn, Russia Biomarker Data During the Mid-Pleistocene Transition

description: The Mid-Pleistocene Transition (MPT) is a widely recognized global climate shift occurring between approximately 1,250 to 700 ka. At this time, Earth's climate underwent a major transition from dominant 40 kyr glacial-interglacial cycles to quasi-100 kyr cycles. The cause of the MPT remains a puzzling aspect of Pleistocene climate. Presently, there are few, if any, continuous MPT records from the Arctic yet understanding the role and response of the high latitudes to the MPT is required to better evaluate the causes of this climatic shift. Here, we present new continental biomarker records of temperature and vegetation spanning 1,142 to 752 ka from Lake El'gygytgyn (Far East Russia). We reconstruct warm-season temperature variations across the MPT based on branched glycerol dialkyl glycerol tetraethers (brGDGTs) using the MBT'5ME proxy. The new Arctic temperature record does not display an overall cooling trend during the MPT but does exhibit strong glacial-interglacial cyclicity. Spectral analysis demonstrates persistent obliquity and precession pacing over the study interval and reveals substantial sub-orbital temperature variations at ~900 kyr during the first skipped interglacial. Interestingly, Marine Isotope Stage (MIS) 31, which is widely recognized as a particularly warm interglacial, does not exhibit exceptional warmth at Lake El'gygytgyn. Instead, we find that MIS 29, 27 and 21 were as warm or warmer than MIS 31. In particular, MIS 21 (~870 to 820 ka) stands out as an especially warm and long interglacial in the continental Arctic while MIS 25 is a notably cold interglacial. Throughout the MPT, Lake El'gygytgyn pollen data exhibits a long-term drying trend, with a shift to an increasingly open landscape noted after around 900 ka (Zhao et al., 2018), which is also reflected in our higher plant leaf wax (n-alkane) distributions. Although the mechanisms driving the MPT remain a matter of debate, our new climate records from the continental Arctic exhibit some similarities to changes noted around the North Pacific region. Overall, the new organic geochemical data from Lake El'gygytgyn contribute to expanding our knowledge of the high-latitude response to the MPT.
description: Dataset includes concentrations and fractional abundances of isoprenoid GDGTs, branched GDGTs, and leaf wax n-alkanes from 752-1142 ka at Lake El'gygytgyn, Far East Russia. The age model used in this study is that presented by Nowaczyk et al., 2013, Climate of the Past.
Provided Keywords: branched GDGT, mid-Pleistocene, MPT, Arctic, Lake