cometadata/datacite-titles-descriptions-related-identifiers huggingface dataset:
DOI: 10.25921/xvmp-va15
title: NOAA/WDS Paleoclimatology - Tropical Pacific Sea Surface Temperature Data from 760-1960 CE

description: ENSO and the mean zonal sea surface temperature gradient (dSST) of the tropical Pacific are important drivers of global climate and vary on decadal to centennial time scales. However, the relationship between dSST and ENSO cannot be assessed with the short instrumental record, and is uncertain in proxy data, with intervals of both stronger and weaker ENSO postulated to occur with overall strong dSST in the past. Here we assess the ENSO-dSST relationship during the last millennium using general circulation models (GCMs) participating in phase 3 of the Paleoclimate Modeling Intercomparison Project. Last millennium GCM simulations show diversity in the strength and direction of the ENSO-dSST relationship. Yet, the models that best simulate modern tropical Pacific climate frequently have a more negative ENSO-dSST correlation. Thus, last millennium tropical Pacific climate simulations support the likelihood of enhanced ENSO during decadal to centennial periods of reduced tropical Pacific dSST. However, the alternating directional ENSO-dSST relationship in all model simulations suggests that this relationship is not constant through time and is likely controlled by multiple mechanisms.
description: NOAA pages where original data was obtained: https://www.ncdc.noaa.gov/paleo/study/8699, https://www.ncdc.noaa.gov/paleo/study/12906, https://www.ncdc.noaa.gov/paleo/study/10420, https://www.ncdc.noaa.gov/paleo/study/5917, https://www.ncdc.noaa.gov/paleo/study/19874. PANGAEA page where original data was obtained: https://doi.pangaea.de/10.1594/PANGAEA.65431
       Provided Keywords: ENSO
DOI: 10.25921/xqnj-4t39
title: NOAA/WDS Paleoclimatology - Larson - Duck Egg County Forest - QUMA - ITRDB WI028

description: New and updated multi-century tree-ring chronologies from living oak trees, remnants, and archeological beams from across the Driftless Area of southwest Wisconsin and northeast Iowa, USA, were developed to fill a spatial gap in the network of available tree-ring chronologies. We produced a robust 303-year summer drought reconstruction (June-August Palmer's Modified Drought Index (PMDI): r2 = 0.45) that identified clusters of extreme droughts and pluvials (PMDI <= -4.0 or >= 4.0) in the early 1700s and more even distributions of drought conditions, with the exception of the post 1930s period when drought became relatively infrequent. Compared to the Living Blended Drought Atlas (LBDA) and the North American Drought Atlas (NADA), our reconstruction more accurately represented moderate moisture conditions across the Driftless Area, the NADA and LBDA more closely represented extreme pluvials, and our reconstruction and the LBDA better represented extreme drought years. The three reconstructions largely captured the same high-frequency variability in drought conditions and differed most at low frequencies. Significant correlations were identified between our reconstruction and corn (r = 0.30, n = 91, p = 0.002) and soybean (r = 0.25, n  = 81, p = 0.012) yields, with the strength of the correlations increasing over recent decades suggesting a tighter coupling of interannual climate variability and crop productivity in the region. Superposed epoch analyses indicated significantly wetter conditions in the Driftless Area two years after major volcanic eruptions. In the context of long-term climatic variability, the Driftless Oaks drought reconstruction demonstrated that drought and pluvial conditions more extreme than those experienced during the instrumental record have occurred in the past.
description: Oak ring width data from the Driftless Area of southwest Wisconsin and northeast Iowa, USA, sampled from living oak trees, remnants, and archeological beams. NOAA Template Raw Measurements file added 2021-10-19.
DOI: 10.25921/xt5k-kn56
title: NOAA/WDS Paleoclimatology - Birch - Cedar Breaks National Monument - PCEN - ITRDB UT546

description: Tree rings provide an invaluable long-term record for understanding how climate and other drivers shape tree growth and forest productivity. However, conventional tree-ring analysis methods were not designed to simultaneously test effects of climate, tree size, and other drivers on individual growth. This has limited the potential to test ecologically relevant hypotheses on tree growth sensitivity to environmental drivers and their interactions with tree size. Here, we develop and apply a new method to simultaneously model nonlinear effects of primary climate drivers, reconstructed tree diameter at breast height (DBH), and calendar year in generalized least squares models that account for the temporal autocorrelation inherent to each individual tree's growth. We analyze data from 3811 trees representing 40 species at 10 globally distributed sites, showing that precipitation, temperature, DBH, and calendar year have additively, and often interactively, influenced annual growth over the past 120 years. Growth responses were predominantly positive to precipitation (usually over >=3-month seasonal windows) and negative to temperature (usually maximum temperature, over <=3-month seasonal windows), with concave-down responses in 63% of relationships. Climate sensitivity commonly varied with DBH (45% of cases tested), with larger trees usually more sensitive. Trends in ring width at small DBH were linked to the light environment under which trees established, but basal area or biomass increments consistently reached maxima at intermediate DBH. Accounting for climate and DBH, growth rate declined over time for 92% of species in secondary or disturbed stands, whereas growth trends were mixed in older forests. These trends were largely attributable to stand dynamics as cohorts and stands age, which remain challenging to disentangle from global change drivers. By providing a parsimonious approach for characterizing multiple interacting drivers of tree growth, our method reveals a more complete picture of the factors influencing growth than has previously been possible.
description: Tree-ring chronologies of Picea engelmannii at Cedar Breaks National Monument (1688 - 2019). Collected from living and visibly healthy P. engelmannii within and around the Utah Forest Dynamics Plot located within Cedar Breaks National Monument, Utah, USA. Collected in July of 2020. NOAA Template Raw Measurements file added 2021-02-22
DOI: 10.25921/xm5g-ss62
title: NOAA/WDS Paleoclimatology - Stan fire data from Manzanita High - IMPD USMH-001

description: Forests on tribal lands in the western United States have seen the return of low-intensity surface fires for several decades longer than forests on non-tribal lands. We examined the surface fire regime in a ponderosa pine-dominated (Pinus ponderosa) forest on the Hualapai tribal lands in the south-western United States. Using fire-scarred trees, we inferred temporal (frequency and seasonality) and spatial (synchrony) attributes and regulators of the fire regime over three land-use periods (historical, suppression, modern) between 1702 and 2007. Patterns of fire frequency and synchrony were similar, but fire seasonality was dissimilar, between the historical and modern periods. Logistic regression and generalised linear mixed models identified a suite of variables representing fuels, climate and human land uses that were associated with the probability of a site burning. Combined, these results allow for valuable insights regarding past fire spread and variability in fire frequency throughout our study area. In some respects, the current distinct fire regime in our study area, which predominately consists of prescribed fires implemented since the 1960s, resembles the past frequent surface fire regime that occurred here and in similar forest types on non-tribal lands in the south-western United States. Our results will be useful for informing adaptive management throughout the region as climate warms.
description: This dataset was contributed as part of the North American Tree-ring Fire Scar Synthesis (NAFSS) project (https://www.ncei.noaa.gov/access/paleo-search/study/34853). Data were contributed to the project from the original data generators.

Sample Storage Location: School of Forest Resources, Northern Arizona University
Dating Method: Dated
Related ITRDB_Chronology: Not Applicable

Fire scar data from this site are available in FHX2 format at:
  https://www.ncei.noaa.gov/pub/data/paleo/firehistory/firescar/northamerica/usmh-001.fhx
along with associated metadata at:
  https://www.ncei.noaa.gov/pub/data/paleo/firehistory/firescar/northamerica/usmh-001-noaa.txt
DOI: 10.25921/xpva-7788
title: NOAA/WDS Paleoclimatology - Esper - Ailijärvi Inari Dry - PISY - ITRDB FINL079

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 2021-10-19.
DOI: 10.25921/xgww-a365
title: NOAA/WDS Paleoclimatology - Esper - Sotkamo Dry - PISY - ITRDB FINL095

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 2021-10-19.
DOI: 10.25921/x33w-7q50
title: NOAA/WDS Paleoclimatology - Lingyang Reef, Yongle Atoll South China Sea Coral, Sr/Ca, 1994-2013 CE

description: Reconstructions of ocean temperatures prior to the industrial era serve to constrain natural climate variability on decadal to centennial timescales, yet relatively few such observations are available from the west Pacific Warm Pool. Here we present multiple coral-based sea surface temperature reconstructions from Yongle Atoll, in the South China Sea over the last ~1,250 years (762–2013 Common Era [CE]). Reconstructed coral Sr/Ca-sea surface temperatures indicate that the “Little Ice Age (1711–1817 CE)” period was ~0.7°C cooler than the “Medieval Climate Anomaly (913-1132 CE)” and that late 20th century warming of the western Pacific is likely unprecedented over the past millennium. Our findings suggest that the Western Pacific Warm Pool may have expanded (contracted) during the Medieval Climate Anomaly (Little Ice Age), leading to a strengthening (weakening) of the Asian summer monsoon, as recorded in Chinese stalagmites.
DOI: 10.25921/x458-wh24
title: NOAA/WDS Paleoclimatology - Vanoni - Val Sumvitg - PCAB - ITRDB SWIT398

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: Reference: 
# Vanoni M. 2012. Klimatische Einflusse auf die Wachstumsvariabilitat von Weisstanne und Fichte entlang des Weisstannen-Ausbreitungsgradienten. Master thesis. ETH Zurich, Zurich. NOAA Template Raw Measurements file added 2021-05-03.
DOI: 10.25921/xzd6-ap67
title: NOAA/WDS Paleoclimatology - Lake Lading, Indonesia 1,100 Year Grain Size and Geochemical Flood Data

description: Extreme precipitation events are one of the most consequential components of climate change for society. The El Niño-Southern Oscillation (ENSO) is the dominant mode of precipitation variability in the tropics and causes severe flooding and drought in many socioeconomically vulnerable regions. It remains unclear how tropical rainfall extremes and ENSO are changing in response to anthropogenic forcing, demanding that we investigate the relationships between precipitation, ENSO, and external forcing in the past. Lake sediment records have provided benchmark records of extreme flood events from the eastern tropical Pacific, where paleofloods have been interpreted to reflect El Niño events during the last millennium. However, the connections between flooding and ENSO variability in this region are uncertain, and the eastern Pacific can only capture precipitation events driven by El Niño, not La Niña. Thus, it is unclear how the ENSO system and tropical rainfall extremes have changed in the recent past. Here, we reconstruct flood events during the past millennium using a lake sediment record from East Java, Indonesia, which can provide insight into flooding driven by La Niña. We detect flood frequency variations in the western tropical Pacific that are highly coherent with records from the eastern part of the basin over the past millennium. Our findings demonstrate that heavy rainfall and flooding occurs more frequently on both sides of the tropical Pacific during periods of warmer Northern Hemisphere mean temperatures, implying that ENSO-driven rainfall extremes could intensify in the near future.
description: Lake Lading, Indonesia sediment grain size and geochemistry interpreted to reflect a flood history for the past 1,100 years.
DOI: 10.25921/xhhx-bm17
title: NOAA/WDS Paleoclimatology - West Pacific Warm Pool B/Ca, Mg/Ca Data and Sea Surface Temperature Reconstructions since the Pliocene

description: The West Pacific Warm Pool (WPWP)'s response to increased pCO2 during the Pliocene is a key model validation target. Different temperature proxies show different trends: The foraminiferal Mg/Ca sea surface temperature (SST) record shows Pliocene WPWP temperatures ~1.2°C cooler than today (Wara et al., 2005, https://doi.org/10.1126/science.1112596), whereas a TEX86 study finds a cooling trend and claims the Pliocene WPWP was warmer than today (Zhang et al., 2014, https://doi.org/10.1126/science.1246172). We focus on understanding biases in Mg/Ca data as the best way to constrain the temperature of the Pliocene WPWP. The strongest nonthermal controls on foraminiferal Mg/Ca are Mg/Ca of seawater and dissolution. Dissolution, which imparts a cool bias to Mg/Ca temperatures, depends on Δ[CO32−], the difference from the carbonate ion concentration needed for calcite saturation. Thus, Pliocene proxy discrepancies might stem from varying Δ[CO32−] over time. To constrain the effect of changing dissolution on the Mg/Ca data, we collected benthic foraminiferal B/Ca data (a proxy for Δ[CO32−]) from the WPWP spanning 0–5.5 Ma. We find no long-term trend in Δ[CO32−], but variations above and below the threshold of foraminiferal dissolution yield an ~0.4°C cold bias when averaged over the middle to early Pliocene. Changes in seawater Mg/Ca create an ~0.6°C cold bias in the Pliocene Mg/Ca data. After accounting for these biases, we find that the Pliocene WPWP was ~0.1°C cooler than the late Holocene, ranging from −0.5°C to +0.5°C including all uncertainties. Our reconstruction shows a much lower east-west temperature gradient in the Pliocene tropical Pacific than today, supporting a permanent El Niño-like “El Padre” state.
description: Provided Keywords: SST, foraminifera, Mg/Ca, dissolution
DOI: 10.25921/xjvw-2v89
title: NOAA/WDS Paleoclimatology - Larson - Bohlin - QUMA - ITRDB WI018

description: New and updated multi-century tree-ring chronologies from living oak trees, remnants, and archeological beams from across the Driftless Area of southwest Wisconsin and northeast Iowa, USA, were developed to fill a spatial gap in the network of available tree-ring chronologies. We produced a robust 303-year summer drought reconstruction (June-August Palmer's Modified Drought Index (PMDI): r2 = 0.45) that identified clusters of extreme droughts and pluvials (PMDI <= -4.0 or >= 4.0) in the early 1700s and more even distributions of drought conditions, with the exception of the post 1930s period when drought became relatively infrequent. Compared to the Living Blended Drought Atlas (LBDA) and the North American Drought Atlas (NADA), our reconstruction more accurately represented moderate moisture conditions across the Driftless Area, the NADA and LBDA more closely represented extreme pluvials, and our reconstruction and the LBDA better represented extreme drought years. The three reconstructions largely captured the same high-frequency variability in drought conditions and differed most at low frequencies. Significant correlations were identified between our reconstruction and corn (r = 0.30, n = 91, p = 0.002) and soybean (r = 0.25, n  = 81, p = 0.012) yields, with the strength of the correlations increasing over recent decades suggesting a tighter coupling of interannual climate variability and crop productivity in the region. Superposed epoch analyses indicated significantly wetter conditions in the Driftless Area two years after major volcanic eruptions. In the context of long-term climatic variability, the Driftless Oaks drought reconstruction demonstrated that drought and pluvial conditions more extreme than those experienced during the instrumental record have occurred in the past.
description: Oak ring width data from the Driftless Area of southwest Wisconsin and northeast Iowa, USA, sampled from living oak trees, remnants, and archeological beams. NOAA Template Raw Measurements file added 2021-10-19.
DOI: 10.25921/x747-z326
title: NOAA/WDS Paleoclimatology - Kiritimati Island and Butaritari Atoll Coral Mn/Ca and Sr/Ca Data from 1989-2012 CE

description: Global surface temperatures during the twentieth century are characterized by multidecadal periods of accelerated or reduced warming, which are thought to be driven by Pacific decadal variability, specifically changes in trade-wind strength. However, the relationship between trade-wind strength and global surface warming remains poorly constrained due to the scarcity of instrumental wind observations. Previous work has shown that corals growing at Tarawa Atoll (1.3°N, 173°E) incorporate dissolved Mn flushed from lagoon sediments by El Niño-related westerly wind events (WWEs), providing records of both westerly wind variability and trade-wind strength (on decadal time scales). Here, we explore the utility of this novel coral Mn/Ca-wind proxy at two nearby islands that also feature west-facing lagoons. Short coral Mn/Ca records from Butaritari (3°N, 173°E) and Kiritimati (2°N, 157.5°W) track WWEs, albeit with some intercolony variability in the magnitude and timing of the signal. Variability in coral Mn/Ca signal intensity among records from Butaritari suggests that wind-driven mixing of the sediment Mn reservoir may be finite and/or localized. At Kiritimati, a coral growing outside the lagoon shows higher Mn/Ca concentrations during the 1997/1998 El Niño event, suggesting that nearshore sediments may be an overlooked dissolved Mn reservoir. Taken together, these results highlight a need for additional studies of Mn reservoir variability within and across atolls that hold promise for recording WWEs. These results also suggest that Mn/Ca records from multiple coral colonies and sites are needed to generate robust coral-based wind reconstructions, particularly from sites with unknown or complex Mn transport pathways.
DOI: 10.25921/xseg-d327
title: NOAA/WDS Paleoclimatology - Foraminifer Isotope Data (d15N, d13C, d18O) and Modeling of Nordic Seas Hydrography and Circulation during MIS 11

description: The Atlantic meridional overturning circulation (AMOC) is a critical element of Earth’s climate system and it is currently weakening. While this weakening is frequently explained by freshwater-driven disruptions to ocean convection, uncertainties about the impacts of prolonged freshening limit our capacity to predict its future state. For example, during the warm and unusually long marine isotope stage (MIS) 11 interglacial, ~424 to 374 ka, several lines of evidence suggest that a strong AMOC persisted concomitant with fresher-than-present conditions in the Nordic Seas, challenging our current understanding of convection. Here, we present new foraminifer-bound nitrogen isotope data along with multiple additional geochemical reconstructions of upper-ocean hydrography in the Nordic Seas during this anomalous interval. Our data suggest that a weak summer stratification was driven by the prolonged upper-ocean accumulation of freshwater beginning at the onset of the climatic optimum, ~410 to 407 ka, which could have helped precondition the region for convection. A box model constrained by paleo-proxy data additionally suggests that the density gradient between the subpolar North Atlantic and Nordic Seas was favorable for the onset of convection in the Nordic Seas during the climatic optimum. It is thus likely that the Nordic Seas became a locus of convection around this time. Enhanced northern-hemisphere heating driven by convection in the Nordic Seas may have been important for delaying glacial conditions, thereby driving the extended warming characteristic of MIS 11. Such findings may also be relevant for near-future changes under a relatively fresher high-latitude North Atlantic.
description: d15N, d13C and d18O records of Nordic Seas planktic foraminifers during MIS 11; data-constrained model results of North Atlantic circulation during MIS 11
      Provided Keywords: Atlantic meridional overturning circulation, Nordic Seas, Marine isotope stage 11, Nitrogen isotopes, Stable isotope geochemistry, Paleoceanography