cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.25921/d2xa-v889
title: NOAA/WDS Paleoclimatology - Peace-Athabaska 158 Year Lake Level Reconstructions

description: The fact that dendrochronology can be a useful tool in water resources management is demonstrated by a study of past changes in lake levels. The study was necessitated by the recent (1967) closure of the gates on the W.A.C. Bennett Dam on the Peace River in British Columbia, causing a drop in water levels of Lake Athabasca, the lake levels control water level undulations in a series of smaller lakes which lie in the 1.5 million acre delta area along its western edge in Alberta. The W.A.C. Bennett Dam has by its regulation of the Peace River affected the river's historical role of creating a hydraulic dam during early summer flood stages thereby preventing outflow from Lake Athabasca and inducing annual inundation of the delta area. Because the ecololgy of the lake and adjacent delta region has depended on the now attenuated snow-melt flooding from the Upper Peace River Basin, it became necessary to consider some means of artificially inducing this annual inundation. It was not known, however, what the long-term water level changes were around which the present ecology had developed. Continuous historical lake level records exist only for the period 1935-1967. Was this period one of anomalously high or low water levels? Relatively old white spruce trees growing along natural levees of the channels in the delta region were found to contain tree-ring records that reflected the water stages in the channels. Because the water levels in the channels could be correlated with lake levels, it was possible to use the three-ring series to extend the known 33-year record of lake level changes to 158 years. By using canonical analysis and 10-day mean lake levels for three different subperiods in the 33-year period of calibration, along with tree-ring series from appropriately chosen stands of white spruce, reconstructions were made of the long-term record for late May, early July, and late September. The reconstructed record shows that the May 21-30 lake levels have been three times as variable in the past as in the period of historical record (1935-1967), the July 11-20 levels twice as variable, and the September 21-30 levels 10% less variable. However, the mean water level for each of the three subperiods for the long-term record is very close to the means for the period of historical record. The reconstructed record shows that, before the dam gates were closed, there was only one three-year period (1866-1868) in which the lake levels were as low as they have been since closure of the gates (that is, 1967-1970). (Levels were nearly as low, however, during the period 1942-1945.
description: Peace-Athabaska Lake Level Reconstructions, in feet above mean sea level, for 3 intervals of time within the season: May 21-30, July 11-20, and Sep 21-30.  Reconstructions based on tree-ring data from 1810-1967 CE.
DOI: 10.25921/dcgb-av38
title: NOAA/WDS Paleoclimatology - Niger Delta Mg/Ca Data over the Last 21 Kyr

description: Multiple lines of evidence show that cold stadials in the North Atlantic were accompanied by both reductions in Atlantic Meridional Overturning Circulation (AMOC) and collapses of the West African Monsoon (WAM). Although records of terrestrial change identify abrupt WAM variability across the deglaciation, few studies show how ocean temperatures evolved across the deglaciation. To identify the mechanism linking AMOC to the WAM, we generated a new record of subsurface temperature variability over the last 21 kyr based on Mg/Ca ratios in a sub-thermocline dwelling planktonic foraminifera in an Eastern Equatorial Atlantic (EEA) sediment core from the Niger Delta.  Our subsurface temperature record shows abrupt subsurface warming during both the Younger Dryas (YD) and Heinrich Event 1. We also conducted a new transient coupled ocean-atmosphere model simulation across the YD that better resolves the western boundary current dynamics and find a strong negative correlation between AMOC strength and EEA subsurface temperatures caused by changes in ocean circulation and rainfall responses that are consistent with the observed WAM change. Our combined proxy and modeling results provide the first evidence that an oceanic teleconnection between AMOC strength and subsurface temperature in the EEA impacted the intensity of the WAM on millennial time scales.
description: Provided Keywords: Deglaciation, abrupt climate change, West African Monsoon, Mg/Ca temperature, subsurface temperature, Niger delta, Younger Dryas, Heinrich Event 1, LGM, GCM modelling, Globorotalia crassaformis
DOI: 10.25921/dskr-zw12
title: NOAA/WDS Paleoclimatology - Magurici Cave, Romania 1,130 Year Bat Guano d13C and d15N Data

description: A 285-cm core of bat guano was recovered from Magurici Cave in north-west Romania and analyzed for d13C, d15N and pollen. Guano deposition occurred from AD 881 until 1240 and from AD 1651 to 2013, allowing for the interpretation of summer variations in precipitation and temperature during the Medieval Warm Period (MWP) and the Little Ice Age (LIA). A 2 per mil increase in d13C, 1.5 per mil decrease in d15N, and the presence of Ulmus, Quercus and Carpinus betulus indicate a warm and dry MWP occurred in the region. The lack of deposition during the beginning of the LIA suggests a possible climate-induced change in prey availability resulting in bats vacating the cave. Variation of d13C values between -25 and -23 per mil at AD 1650 (LIA) indicates similar drier conditions as at the end of MWP. However, a 2 per mil decrease in d13C values that occurred between AD 1790 and 1900 suggests climate was trending towards wetter conditions at the end of the LIA. From AD 1938 to 2013, d13C values appear to be more influenced by temperature, indicating that this parameter had a more significant effect on carbon discrimination than water availability.
description: Stable isotope (d13C, d15N) data from bat guano collected in Magurici Cave, Romania, for CE 881-1240 and CE 1651-2013
DOI: 10.25921/d45r-7y89
title: NOAA/WDS Paleoclimatology - Appleton - Palisade - TSME - ITRDB OR104

description: Snow dominates the hydrology and climate of the United States' central Pacific Coast, but because local measurements of snowpack and winter precipitation often extend back only a few decades, observations by themselves are not adequate to describe potential amplitude of wintertime conditions. Here we present a set of updated and extended mountain hemlock (Tsuga mertensiana [Bong.] Carr.) tree-ring width records from Crater Lake National Park, Oregon, and use these data to make inferences about snowpack prior to the start of instrumental monitoring. In July and August 2013, we collected cores from 228 trees at seven high-elevation hemlock stands that surround the crater's rim. The oldest tree had an inner ring date of A.D. 1474, and the longest ring-width chronology maintained a satisfactory common signal back to the middle of the 16th century. The growth of high-elevation mountain hemlock is strongly and inversely related to cool-season precipitation, making these records some of the most southerly examples of a robust inverse cool-season moisture signal in North American tree rings. The growth of these snow-limited forests does not appear to have been affected by the substantial decline in spring snowpack observed in the past two decades across the broader Cascade Range, and we did not find any indication of changing relationships between tree growth and either monthly or seasonal winter precipitation since the early 1990s. The exceptional three-year sequence in Crater Lake tree rings between A.D. 1809 and 1811, which includes the narrowest ring since A.D. 1540 and anatomical abnormalities produced by cold weather, leads us to conclude that 1809-1810 was the most snowy and severe winter to affect south-central Oregon during the past four and a half centuries.
description: NOAA Template Raw Measurements file added 2019-02-08.
DOI: 10.25921/d4mb-ed56
title: NOAA/WDS Paleoclimatology - Madagascar Deglacial Speleothem Stable Isotope Data

description: The global paleomonsoon concept predicts an antiphase response of monsoon rainfall in the northern and southern hemispheres at timescales where there is asymmetric solar forcing and/or asymmetric hemispheric temperature changes. However, as different monsoon systems have different sensitivities to local, regional and global forcing, rainfall response may vary regionally, particularly during large global climatic changes such as the last deglaciation where warming occurred in both hemispheres. Despite its role as a key southern hemisphere counterpart to the Arabian and Indian summer monsoons, the behavior of the summer monsoon in the southern hemisphere of the Indian Ocean during the last deglaciation is unknown. Therefore, we present a new high-resolution, precisely dated, and replicated speleothem stable isotope record from Tsimanampesotse National Park in southwest Madagascar that covers the last deglaciation. We show that speleothem growth phases respond largely to movements of the southern hemisphere summer Hadley circulation (summer extent of the tropical rainbelt/mean Intertropical Convergence Zone location), with some contribution from sea-surface temperature changes at key times, such as during the Bolling-Allerod. In contrast, speleothem d18O responds primarily to sea-surface temperature, in particular the location of the deep atmospheric convection isotherm, while summer Hadley circulation changes take a secondary role. Separating the varying influences of temperature and atmospheric circulation in controlling southwest Madagascan rainfall is critical to understanding rainfall variability in both the past and the future.
description: Speleothem stable isotope (d13C, d18O) data from 2 stalagmites collected in Tsimanampesotse National Park, southwest Madagascar, for the deglacial interval (~22-11 kyrbp).
DOI: 10.25921/drxq-xe93
title: NOAA/WDS Paleoclimatology - Northeast Atlantic Foramifinferal Abundance, d15N and Sea Water Temperature Data during the last 10ka

description: In the North Atlantic, the subpolar gyre (SPG) connects tropical and high latitude waters, playing a leading role in deep-water formation, propagation of Atlantic water into the Arctic, and as habitat for many ecosystems. Detailed instrumental records spanning the last few decades document significant decadal variability in SPG circulation, with associated hydrographic and ecological changes. Emerging longer-term records provide circumstantial evidence that the North Atlantic also experienced centennial trends during the 20th century. Here, we use marine sediment records to show that there has been a long-term change in SPG circulation during the industrial era, most of which occurred during the 20th century. Moreover, we show that the shift and modern SPG configuration are unprecedented in the last 10,000 years. Modern SPG dynamics have resulted in an expansion of subtropical ecosystems into new habitats and likely also altered the northward transport of heat to high latitudes.
description: Provided Keywords: foraminifera, industrial-era
DOI: 10.25921/dm26-9y35
title: NOAA/WDS Paleoclimatology - Equatorial Pacific Trace Metal and CaCO3 Data during the last 4,500 years

description: El Niño Southern Oscillation (ENSO) is the largest source of interannual climate variability on Earth today; however, future ENSO remains difficult to predict. Evaluation of paleo-ENSO may help improve our basic understanding of the phenomenon and help resolve discrepancies among models tasked with simulating future climate. Individual foraminifera analysis (IFA) allows continuous down-core records of ENSO-related temperature variability through the construction and comparison of paleotemperature distributions; however, there has been little focus on calibrating this technique to modern conditions. Here, we present data from individual measurements of Mg/Ca in two species of planktic foraminifera, surface dwelling Globigerinoides ruber and thermocline dwelling Neogloboquadrina dutertrei, from nine core-tops across the equatorial Pacific (n  70 per core). Population variance, kernel probability density functions, and quantile-quantile analyses are used to evaluate the shape of each Mg/Ca-temperature distribution and to compare them to modern conditions using monthly temperatures from the Simple Ocean Data Assimilation. We show that populations of individual Mg/Ca measurements in both G. ruber and N. dutertrei reflect site-specific temperature distribution shapes and variances across the equatorial Pacific when accounting for regional differences in depth habitats. Individual measurements of both taxa capture zonal increases in population variance from the western equatorial Pacific to the central equatorial Pacific, and a spatially heterogeneous eastern equatorial Pacific, consistent with modern conditions. Lastly, we show that populations of individual Mg/Ca measurements are able to recover meaningful differences in temperature variability between sites within the eastern equatorial Pacific, lending support to this tool's application for paleo-ENSO reconstructions.
description: Sites used: ERDC 92Bx, MGL1208-26MC, MGL1208-14MC, PLDS 72Bx, KNR195-5 MC-42A, RC13-140, KNR195-5 MC-11A, OC73-1-2, RC23-22.
   Provided Keywords: individual foraminifera, ENSO, Mg/Ca
DOI: 10.25921/dyed-mt71
title: NOAA/WDS Paleoclimatology - Azpeleta Tarancón fire data from Potato Patch NM, south central New Mexico - IMPD USPP-002

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.

description: This site was sampled to assess the spatiotemporal variability of fire regimes on Mescalero Apache lands and lands adjacent.
DOI: 10.25921/d5yq-kg85
title: NOAA/WDS Paleoclimatology - Upper Missouri River Basin 1,200 Year Streamflow Reconstructions

description: Paleohydrologic records can provide unique, long-term perspectives on streamflow variability and hydroclimate for use in water resource planning. Such long-term records can also play a key role in placing both present day events and projected future conditions into a broader context than that offered by instrumental observations. However, relative to other major river basins across the western United States, a paucity of streamflow reconstructions has to date prevented the full application of such paleohydrologic information in the Upper Missouri River Basin. Here we utilize a set of naturalized streamflow records for the Upper Missouri and an expanded network of tree-ring records to reconstruct streamflow at thirty-one gaging locations across the major headwaters of the basin. The reconstructions explain an average of 68% of the variability in the observed streamflow records and extend available records of streamflow back to 886 CE on average. Basin-wide analyses suggest unprecedented hydroclimatic variability over the region during the Medieval period, similar to that observed in the Upper Colorado River Basin, and show considerable synchrony of persistent wet-dry phasing with the Colorado River over the last 1200 years. Streamflow estimates in individual sub-basins of the Upper Missouri demonstrate increased spatial variability in discharge during the Little Ice Age (~1400-1850 CE) compared with the Medieval Climate Anomaly (~800-1400 CE). The network of streamflow reconstructions presented here fills a major geographical void in paleohydrologic understanding and now allows for a long-term assessment of hydrological variability over the majority of the western U.S.
description: Upper Missouri River instrumental and reconstructed streamflow data for 31 gauge stations over the past 1,200 years
DOI: 10.25921/dp7t-w436
title: NOAA/WDS Paleoclimatology - Sauchyn - Waldron Ranch - PSME - ITRDB CANA583

description: Tree ring data from the International Tree Ring Data Bank and World Data Center for Paleoclimatology archives.  Most data sets include raw treering measurements (most are annual ring width, with some collections of earlywood or latewood width or wood density), plus chronologies (standardized growth indices for a site compiled from multiple treering samples). Reconstructions of climate variables are included with some of these data sets.  Each data type is stored in a separate data file; the data type is coded into the file name. For details please see: http://www.ncdc.noaa.gov/paleo/treeinfo.htmll
description: Upper Missouri River Basin Streamflow project NOAA Template Raw Measurements file added 2020-01-15.
DOI: 10.25921/d7j5-g131
title: NOAA/WDS Paleoclimatology - Horseshoe Lake, Illinois 1,500 Year Multiproxy Sediment Data

description: Cahokia is the largest documented urban settlement in the pre-Columbian United States. Archaeological evidence suggests that the city, located near what is now East St. Louis, Illinois, began to rapidly expand starting around AD 1050. At its height, Cahokia extended across 1000 ha and included large plazas, timber palisade walls, and hundreds of monumental earthen mounds. Following several centuries of occupation, the city experienced a period of gradual abandonment from about AD 1200 to 1400. Here, we present geochemical data from a 1500-year-old sediment core from nearby Horseshoe Lake that records watershed impacts associated with the growth and decline of Cahokia. Sedimentary analysis shows a distinctive 24-cm-thick, gray, fine-grained layer formed between AD 1150 and 1220 and characterized by low carbonate d13C, elevated sorbed metal concentrations, and higher organic matter d15N. The deposition of this layer is contemporaneous with archaeological evidence of increased agricultural activity, earthen mound construction, and higher populations surrounding the lake. We hypothesize that these human impacts increased soil erosion, producing new sediment sources from deeper soil horizons, and shifted dissolved transport to the lake, producing lower carbonate d13C values, higher concentrations of lead, copper, potassium, and aluminum, and increased d15N, likely due to contributions of enriched nitrogen from sewage.
description: Multiproxy sediment data from cores A12 and E13 collected in Horseshoe Lake, Illinois, for the past 1,500 years
DOI: 10.25921/d2hw-nx45
title: NOAA/WDS Paleoclimatology - de Graauw - James Jarrett House - QUAL - ITRDB WV020

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: Chronology derived from log joists in stone building (James Jarrett House; JJJ). NOAA Template Raw Measurements file added 2020-03-09.
DOI: 10.25921/d3jd-d747
title: NOAA/WDS Paleoclimatology - Marquardt - Mt. Bigelow mixed-needle - PIPO - ITRDB AZ601

description: Rising temperatures and changes in precipitation may affect plant responses, and mountainous regions in particular are sensitive to the impacts of climate change. The Santa Catalina Mountains, near Tucson, Arizona, USA, are among the best known Madrean Sky Islands, which are defined by pine-oak forests. We compared the sensitivity and temporal stability of climate-growth relationships to quantify the growth responses of sympatric taxa of ponderosa pine to changing climate. Three taxa (three-needle, mixed-needle, and five-needle types) collected from southern slopes of two contact zones (Mt. Lemmon, Mt. Bigelow) were evaluated. Positive climate-growth correlations in these semiarid high-elevation pine forests indicated a seasonal shift from summer- to spring-dominant precipitation since 1950, which is a critical time for reproduction. Mixed- and five-needle types responded to winter precipitation, and growth was reduced for the five-needle type when spring conditions were dry. Growth trends in response to temperature and specific to site were observed, which indicated the climate signal can be weakened when data are combined into a single chronology. Significant fluctuations in temperature-growth correlations since 1950 occurred for all needle types. These results demonstrated a dramatic shift in sensitivity of annual tree growth to the seasonality of the limiting factor, and a climatic trend that increases local moisture stress may impact the stability of climate-growth relationships. Moreover, output from temperature-growth analyses based on ring-width data (for example from semiarid sites) that does not account for positive and negative growth trends may be adversely affected, potentially impacting climate reconstructions.
description: Sky Island Pines, Arizona (USA): Mixed-needle Pinus ponderosa var. brachyptera. NOAA Template Raw Measurements file added 2020-03-09.
DOI: 10.25921/dx12-km22
title: NOAA/WDS Paleoclimatology - Vanuatu Modern and Fossil Coral Sr/Ca Data and SST Reconstruction from 1049-1152 CE and 1894-2006 CE

description: Climate model simulations of El Niño–Southern Oscillation (ENSO) behavior for the last millennium demonstrate interdecadal to centennial changes in ENSO variability that can arise purely from stochastic processes internal to the climate system. That said, the instrumental record of ENSO does not have the temporal coverage needed to capture the full range of natural ENSO variability observed in long, unforced climate model simulations. Here we demonstrate a probabilistic framework to quantify changes in ENSO variability via histograms and probability density functions using monthly instrumental and coral‐based sea surface temperature (SST) anomalies from 1900–2005 and 1051–1150 CE. We find that reconstructed SST anomalies from modern corals from the southwest Pacific capture changes in ENSO variability that are consistent with instrumental SST data from the central equatorial Pacific. Fossil coral records indicate 100 years of relatively lower ENSO variability during part of the Medieval Climate Anomaly. Our results demonstrate that periods of reduced ENSO variability can last a century, far longer in duration than modern observations in the instrumental record of ENSO, but consistent with results from unforced climate model simulations.
description: Modern coral Sr/Ca data from Sabine Bank, Vanuatu, southwestern tropical Pacific
       Provided Keywords: Medieval Climate Anomaly