cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.25921/mz30-7314
title: NOAA/WDS Paleoclimatology - Ayr Lake, Baffin Island 570Yr Leaf Wax Hydrogen Isotope and Varve Data

description: We present a multiproxy paleoclimate record using leaf wax hydrogen isotopes (d2Hwax) and varve thickness from Arctic proglacial lake sediments. We also provide one of the first evaluations of the utility of d2Hwax as a paleoclimate proxy in Arctic proglacial lakes. We compare varve thickness and d2Hwax at sub-decadal resolution from 1948 to 2004 AD, and at sub-centennial resolution from 1450 to 2004 AD. Varve thickness and d2Hwax both contain large interannual variability and are anti-correlated during the late twentieth century, suggesting that both proxies respond rapidly, but by different mechanisms, to catchment-scale forcings. At longer time scales, varve thickness exhibits a strong response to Little Ice Age cooling (1661-1827 AD in this record) but does not show evidence for twentieth century warming recorded throughout the Arctic. d2Hwax does record regional-scale temperature changes, with more 2H-depleted values during the Little Ice Age and an abrupt change to more 2H-enriched values in the twentieth century. This corresponds well with a recent Arctic-wide temperature reconstruction in which the seventeenth century is the coldest interval, and the twentieth century is the warmest interval. Our results suggest that d2Hwax is a promising proxy that can be applied at high resolution in proglacial Arctic lakes.
description: Leaf wax hydrogen isotope data (d2Hwax) and varve thickness data from sediments collected in proglacial Ayr Lake, eastern Baffin Island, Arctic Canada. Ayr Lake, Baffin Island: 70.459°N, 70.086°W, 68m elevation, ~50m depth.
DOI: 10.25921/mm6v-0k19
title: NOAA/WDS Paleoclimatology - 2000 Year Precipitation-Based Southern Oscillation Index Reconstruction

description: The El Niño-Southern Oscillation (ENSO) is a coupled ocean-atmosphere climate phenomenon in the tropical Pacific Ocean. The interannual climate variations have been shown to modify both the Hadley and Walker meridional and zonal atmospheric circulations, with strong impacts on global climate. Proxy-based reconstructions of the Southern Oscillation Index on a multi-decadal scale have shown that the strength and frequency of El Niño occurrences have varied over the past millennium. Here we compile reconstructions of precipitation from regions that experience substantial ENSO variability to extend the multidecadal-scale Southern Oscillation Index to include the past 2,000 years. We find that the Medieval Warm Period (~AD 800–1300) was characterized by a negative index, which indicates more El Niño-dominated conditions, whereas during the Little Ice Age (~AD 1400-1850) more La Niña-dominated conditions prevailed. The Southern Oscillation Index we derive is significantly correlated with reconstructions of solar irradiance and mean Northern Hemisphere temperature fluctuations.
description: Reconstruction of a precipitation-based Southern Oscillation 
Index (SOIpr) for the past 2000 years. The Southern Oscillation 
Index (SOI) is positively correlated with precipitation over 
the Indo-Pacific warm pool, and negatively correlated with 
precipitation over the eastern and mid-tropical Pacific. 
Based on this correlation between SOI and precipitation, 
we propose a novel and SOI-like index, SOIpr, as the difference 
between normalized annual rainfalls in the positive rainfall 
anomaly area (PA) of the tropical western Pacific, and the 
negative rainfall anomaly area (NA) of the equatorial eastern 
and mid-Pacific. 

Proxy precipitation records from Indonesia and Galapagos 
were used to calculate SOIpr for the past two millennia. 

The Indonesian rainfall was derived from a salinity reconstruction 
based on planktonic-foraminifera d18O and the Mg/Ca ratio 
(Oppo et al. 2009).  Data available from WDC Paleo at: 
https://www.ncei.noaa.gov/pub/data/paleo/contributions_by_author/
oppo2009/oppo2009.txt

The rainfall history of the Galapagos (7241 BC - AD 2004) 
is derived from a lake level reconstruction which is based 
on the grain size data from the Lago El Junco sediment core  
(Conroy et al. 2008).  Data available from WDC Paleo at: 
https://www.ncei.noaa.gov/pub/data/paleo/paleolimnology/
southamerica/ecuador/galapagos/eljunco2008.txt
DOI: 10.25921/m1bh-9j32
title: NOAA/WDS Paleoclimatology - Wright - Pantiange, Weixi County - ABFO - ITRDB CHIN025

description: The Asian monsoon system affects more than half of humanity worldwide, yet the dynamical processes that govern its complex spatiotemporal variability are not sufficiently understood to model and predict its behavior, due in part to inadequate long-term climate observations. Here we present the Monsoon Asia Drought Atlas (MADA), a seasonally resolved gridded spatial reconstruction of Asian monsoon drought and pluvials over the past millennium, derived from a network of tree-ring chronologies. MADA provides the spatiotemporal details of known historic monsoon failures and reveals the occurrence, severity, and fingerprint of previously unknown monsoon megadroughts and their close linkages to large-scale patterns of tropical Indo-Pacific sea surface temperatures. MADA thus provides a long-term context for recent monsoon variability that is critically needed for climate modeling, prediction, and attribution.
description: Purpose of Collection:  
# Climatology - precipitation analysis  NOAA Template Raw Measurements file added 2019-04-08.
DOI: 10.25921/m930-bq63
title: NOAA/WDS Paleoclimatology - Smith - Cathedral Glacier - TSME - ITRDB CANA491

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 2019-01-27. 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/mzze-2814
title: NOAA/WDS Paleoclimatology - Lake Cadagno Switzerland 11000 Year MBT/CBT Temperature Reconstruction

description: A novel proxy for continental mean annual air temperature (MAAT) and soil pH, the MBT/CBT paleothermometer, is based on the temperature (T) and pH-dependent distribution of specific bacterial membrane lipids (branched glycerol dialkyl glycerol tetraethers – GDGTs) in soil organic matter. Here, we tested the applicability of the MBT/CBT-paleothermometer to sediments from Lake Cadagno, a high Alpine lake in southern Switzerland with a small catchment of 2.4 km2. We analysed the distribution of bacterial GDGTs in catchment soils and in a radiocarbon dated sediment core from the centre of the lake, covering the past 11 000 yr. The distribution of bacterial GDGTs in the catchment soils is very similar to that in the lake's surface sediments, indicating a common origin of the lipids.  Consequently, their transfer from the soils into the sediment record seems undisturbed, probably without any significant alteration of their distribution through in situ production in the lake itself or early diagenesis of branched GDGTs. The MBT/CBT-inferred MAAT estimates from soils and surface sediments are in good agreement with instrumental values for the Lake Cadagno region (~0.5°C). Moreover, downcore MBT/CBT-derived MAAT estimates match in timing and magnitude other proxy-based T reconstructions from nearby locations for the last two millennia. Major climate anomalies recorded by the MBT/CBT-paleothermometer are, for instance, the Little Ice Age (~14th to 19th century) and the Medieval Warm Period (MWP, ~9th to 14th century). Together, our observations indicate the quantitative applicability of the MBT/CBT-paleothermometer to Lake Cadagno sediments. In addition to the MWP, our lacustrine paleo T record indicates Holocene warm phases at about 3, 5, 7 and 11 kyr before present, which agrees in timing with other records from both the Alps and the sub-polar North-East Atlantic Ocean. The good temporal match of the warm periods determined for the central Alpine region with north-west European winter precipitation strength implies a strong and far-reaching influence of the North Atlantic Oscillation on continental European T variations during the Holocene.
description: Lake sediment bacterial lipids data and MBT/CBT temperature reconstruction from Lake Cadagno, Switzerland, for the past 11,000 years.  Mean annual air temperature (MAAT) reconstruction is based on the MBT/CBT paleothermometer, utilizing temperature dependent distribution of specific bacterial membrane lipids in soil organic matter. Lake Cadagno, Switzerland: 46.5507°N, 8.7139°E, 1921m elevation.
DOI: 10.25921/mf4m-4226
title: NOAA/WDS Paleoclimatology - East Lake, Melville Island, Canada 4200 Year Varve Thickness Data

description: A long sedimentary sequence from East Lake, Cape Bounty, Melville Island (74°55'N, 109°32'W) contains a 4200 year-long clastic varved record of paleohydrologic variations at high resolution. Sedimentary elemental geochemistry from micro X-ray fluorescence (m-XRF) and sediment fabric variability reflect changes in sediment sources and lacustrine conditions through time. The sedimentary environment progressed from marine in the mid-Holocene, to estuarian from 2195 BC to 243 AD, to fully lacustrine source after 244 AD. Correlation with local meteorological data indicates that varve thickness (VT) is positively correlated with snow depth on May 1st and negatively correlated with mean Sept-May temperatures. Our paleoclimatic reconstruction from VT series revealed high snow accumulation and warm Sept-May months before 1350 BC, and a period of low snow accumulation and cold Sept-May between 1600-1900 AD that may correspond to the Little Ice Age. The general trends of VT series from Cape Bounty are in phase with the d18O series in Agassiz Ice Cap, and in anti-phase with the VT series from Lower Murray Lake in the northeastern of Queen's Elizabeth Islands (QEI). Low mean Arctic temperatures coincide with clusters of high sediment yield events at East, Nicolay and South Sawtooth Lakes, especially during 1600-1750 AD and 1810-1910 AD. The East Lake record also exhibits the signature of the Atlantic Multidecadal Oscillation (AMO) for periods: 600-850 AD, 1400-1550 AD and 1750-1850 AD.
description: Varve thickness (VT) was measured for the period 2005-1999 AD on a short gravity core (CB06EG1) taken in 2006. Varve thickness was measured for the period 1998 AD-2192 BC on a long gravity core (CB06EV1) taken in 2006. An erosive turbidite eroded sediments from 1972 to 1966 AD. Correlation with instrumental data were made on the 1973 - 2005 AD only. Data are presented along an AD/BC time scale and a Varve Years time scale. 

Caution must be used when interpreting the section from 2192 BC to 243 AD because it was attributed to an estuarine environment that may have affected the varve formation. Chronology was supported by 137-Cs. The counting error sum for two varve counts (#1 and #2) of the same analyst was estimated as mean square error (Lotter and Lemcke, 1999) and it is equal to 4027 +/- 232 years (Table 1 of the paper). Count #2 was selected. 

East Lake, Cape Bounty, Melville Island, Canada: 74°53'N, 109°32'W, 32m depth, 5m asl.
DOI: 10.25921/mzvn-p648
title: NOAA/WDS Paleoclimatology - Ross Sea ANDRILL-2A Middle Miocene Biomarker Data

description: From 20 to 15 million years (Myr) ago, a period of global warmth reversed the previous ice growth on Antarctica, leading to the retreat of the West Antarctic Ice Sheet and the contraction of the East Antarctic Ice Sheet. Pollen recovered from the Antarctic shelf indicates the presence of substantial vegetation on the margins of Antarctica 15.7 Myr ago. However, the hydrologic regime that supported this vegetation is unclear. Here we combine leaf-wax hydrogen isotopes and pollen assemblages from Ross Sea sediments with model simulations to reconstruct vegetation, precipitation and temperature in Antarctica during the middle Miocene. Average leaf-wax stable hydrogen isotope (dD) values from 20 to 15.5 Myr ago translate to average dD values of -50 per mil for precipitation at the margins of Antarctica, higher than modern values. We find that vegetation persisted from 20 to 15.5 Myr ago, with peak expansions 16.4 and 15.7 Myr ago coinciding with peak global warmth and vegetation growth. Our model experiments are consistent with a local moisture source in the Southern Ocean. Combining proxy measurements with climate simulations, we conclude that summer temperatures were about 11°C warmer than today, and that there was a substantial increase in moisture delivery to the Antarctic coast.
description: Paleoprecipitation dD and estimated from leaf wax dD and converted to 
temperature with modern spatial slope and iGRAM model temporal slope.
Vegetation evidence from pollen assemblages and abundances as well as
leaf wax abundance. Samples from Antarctic Drilling Project (ANDRILL)
Site AND2A were used to reconstruct vegetation, precipitation and
temperature during the Middle Miocene (~20 to 12 Ma).

ANDRILL site AND-2A: 77°45.488’ S, 165°16.613’ E, ~384 m water depth,
core to 1139 mbsf, 20-12 Ma

The model is an idealized gray-radiation aquaplanet moist General
Circulation Model (GRAM) with the addition of isotopic tracers (iGRAM).
Results are for experiments where optical depth of the atmosphere to
longwave radiation was varied to mimic the effect of changing
greenhouse gases and thus to change temperatures in the model.
The model was run in T42 resolution (2.8° x 2.8°) and has 30 vertical
layers. The simulation was performed for 1400 days with perpetual 
modern equinox and the results of the last 900 model days are analyzed.
DOI: 10.25921/m3cq-1r22
title: NOAA/WDS Paleoclimatology - Proxy benchmarks for intercomparison of 8.2 ka simulations

description: The Paleoclimate Modelling Intercomparison
Project (PMIP3) now includes the 8.2 ka event as a test
of model sensitivity to North Atlantic freshwater forcing.
To provide benchmarks for intercomparison, we compiled
and analyzed high-resolution records spanning this event.
Two previously-described anomaly patterns that emerge are
cooling around the North Atlantic and drier conditions in
the Northern Hemisphere tropics. Newer to this compilation
are more robustly-deﬁned wetter conditions in the Southern Hemisphere tropics and regionally-limited warming in
the Southern Hemisphere. Most anomalies around the globe
lasted on the order of 100 to 150 yr. More quantitative reconstructions are now available and indicate cooling of ~1C and a ~20% decrease in precipitation in parts of Europe as
well as spatial gradients in d18O from the high to low latitudes. Unresolved questions remain about the seasonality of
the climate response to freshwater forcing and the extent to
which the bipolar seesaw operated in the early Holocene.
description: This compilation of proxy records includes quality-controlled values from cores spanning part or all
of the period between 7,400 and 9,000 calendar years before present, provided on a common age scale
(calendar years before present, where present = 1950 A.D.). The main data file is in comma-separated 
values format and first gives metadata information for each of the cores (i.e., site name, variable 
measured, latitude, longitude, journal citation). Below the metadata, data for all time series are
presented in three columns. The first column is a Time series Index, which identifies the time series
according to the metadata table; the second column is age in calendar years BP; and the third column 
is the proxy timeseries values. Since this data set only spans a period near 8,200 calendar years
before present, these are often subsets of a core's full data. All data from a core as well as chronology 
to FTP files are listed below 
in the "File URL" column.
DOI: 10.25921/mxhv-2704
title: NOAA/WDS Paleoclimatology - Heinlein fire data from San Francisco Peaks (East) - IMPD USSPE001

description: We reconstructed historical fires regimes and contemporary and historical stand structures in the drier mixed conifer forests on the San Francisco Peaks in northern Arizona, USA.  Thirty-four fire-scarred specimens recorded 256 fires from the EAST and WEST study sites. Fires were recorded between 1739 and 1903 for the EAST site and between 1548 and 1947 for the WEST site.  The mean fire return interval (MFI: >= 25% scarred) for the period 1690-1892 was 10 years with a range of 3 to 21 years for the EAST site. The WEST site MFI (period 1612-1876) was 9 years with a range of 3 to 21 years. Seasonal patterns of fire occurrence showed that the majority of fires burned during the summer months. Fire interval (years) means, variances, and distributions between the EAST and WEST sites were not statistically different from one another for the common analysis period of 1690-1876. Historically, both the EAST and WEST sites were dominated by ponderosa pine, with scattered individuals of Douglas-fir, limber pine, and white fir, with tree densities that ranged from 44 to 60 trees per hectare (TPH). Current forest composition has shifted from fire-tolerant ponderosa pine to less fire-tolerant, more shade-tolerant species, with tree densities ranging from 1,516 to over 1,700 TPH.  We suggest that the dramatic structural changes recorded at our study sites occurred since fire regime disruption.
DOI: 10.25921/mpxk-8p95
title: NOAA/WDS Paleoclimatology - Woodhouse - Van Bibber Update - PIPO - ITRDB CO641

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/mwpv-wz52
title: NOAA/WDS Paleoclimatology - Iceland 2000 Year Multiproxy Sediment Data

description: Geochemical, mineralogical and biological indicators preserved in sediments are widely used to reconstruct past climate change, but proxies differ in the degree to which their utility as climate indicators has been validated via laboratory experiments, modern spatial calibrations, or down-core comparisons with instrumental climate data. Multi-proxy studies provide another means of evaluating interpretations of proxies. This paper presents a multi-proxy assessment comparing 19 sub-centennially resolved late Holocene proxy records, covering the period 300-1900 AD, from seven Icelandic marine and lacustrine core sites. We employ simple statistical comparisons between proxy reconstructions to evaluate their correlations over time and, ultimately, their utility as proxies for regional climate. Proxies examined include oxygen isotopic composition of benthic and planktonic foraminifera, abundance of the sea-ice biomarker IP25, allochthonous quartz in marine sediments (a proxy for drift ice around Iceland), marine carbonate abundance, total organic carbon concentration, chironomid assemblages, lacustrine biogenic silica and carbon/nitrogen ratios in lake sediments. Most of the examined proxy records, including temperature and sea-ice proxies, correlate strongly with each other over multi-centennial timescales, and thus do appear to record changes in regional climate.
description: These data were assembled and studied in the Axford et al. 2011 paper. 
The original data were resampled at 100-yr intervals using AnalySeries. 
In this paper the data set also included proxy data from Iceland lakes 
but these data are not included. For the analysis on 6 cores, 
given the different range of measurements, the data were normalized 
(mean = 0±1). The data include quartz wt%, IP25, TOC%, carbonate 
(calcite)%, and 18O on foraminifera. Data from MD99-2258, SW Iceland, 
show little evidence for the presence of sea ice.
DOI: 10.25921/mxwf-c439
title: NOAA/WDS Paleoclimatology - Western Pacific Warm Pool ODP871 500 KYr Foraminiferal d18O and Mg/Ca SST

description: Understanding how global temperature changes with increasing atmospheric greenhouse gas concentrations, or climate sensitivity, is of central importance to climate change research. Climate models provide sensitivity estimates that may not fully incorporate slow, long-term feedbacks such as those involving ice sheets and vegetation. Geological studies, on the other hand, can provide estimates that integrate long- and short-term climate feedbacks to radiative forcing. Because high latitudes are thought to be most sensitive to greenhouse gas forcing owing to, for example, ice-albedo feedbacks, we focus on the tropical Pacific Ocean to derive a minimum value for long-term climate sensitivity. Using Mg/Ca paleothermometry from the planktonic foraminifera Globigerinoides ruber from the past 500 k.y. at Ocean Drilling Program (ODP) Site 871 in the western Pacific warm pool, we estimate the tropical Pacific climate sensitivity parameter (lambda) to be 0.94-1.06°C (W m-2)-1, higher than that predicted by model simulations of the Last Glacial Maximum or by models of doubled greenhouse gas concentration forcing. This result suggests that models may not yet adequately represent the long-term feedbacks related to ocean circulation, vegetation and associated dust, or the cryosphere, and/or may underestimate the effects of tropical clouds or other short-term feedback processes.
description: Mg/Ca paleothermometry from the planktonic foraminifera Globigerinoides ruber from the past 500 k.y. at Ocean Drilling Program (ODP) Site 871 in the western Pacific warm pool.