Data Descriptor: A global multiproxy database for temperature reconstructions of the Common Era

Reproducible climate reconstructions of the Common Era (1 CE to present) are key to placing industrial-era warming into the context of natural climatic variability. Here we present a community-sourced database of temperature-sensitive proxy records from the PAGES2k initiative. The database gathers 692 records from 648 locations, including all continental regions and major ocean basins. The records are from trees, ice, sediment, corals, speleothems, documentary evidence, and other archives. They range in length from 50 to 2000 years, with a median of 547 years, while temporal resolution ranges from biweekly to centennial. Nearly half of the proxy time series are significantly correlated with HadCRUT4.2 surface temperature over the period 1850-2014. Global temperature composites show a remarkable degree of coherence between high-and low-resolution archives, with broadly similar patterns across archive types, terrestrial versus marine locations, and screening criteria. The database is suited to investigations of global and regional temperature variability over the Common Era, and is shared in the Linked Paleo Data (LiPD) format, including serializations in Matlab, R and Python.(TABLE)Since the pioneering work of D'Arrigo and Jacoby1-3, as well as Mann et al. 4,5, temperature reconstructions of the Common Era have become a key component of climate assessments6-9. Such reconstructions depend strongly on the composition of the underlying network of climate proxies10, and it is therefore critical for the climate community to have access to a community-vetted, quality-controlled database of temperature-sensitive records stored in a self-describing format. The Past Global Changes (PAGES) 2k consortium, a self-organized, international group of experts, recently assembled such a database, and used it to reconstruct surface temperature over continental-scale regions11 (hereafter, ` PAGES2k-2013').This data descriptor presents version 2.0.0 of the PAGES2k proxy temperature database (Data Citation 1). It augments the PAGES2k-2013 collection of terrestrial records with marine records assembled by the Ocean2k working group at centennial12 and annual13 time scales. In addition to these previously published data compilations, this version includes substantially more records, extensive new metadata, and validation. Furthermore, the selection criteria for records included in this version are applied more uniformly and transparently across regions, resulting in a more cohesive data product.This data descriptor describes the contents of the database, the criteria for inclusion, and quantifies the relation of each record with instrumental temperature. In addition, the paleotemperature time series are summarized as composites to highlight the most salient decadal-to centennial-scale behaviour of the dataset and check mutual consistency between paleoclimate archives. We provide extensive Matlab code to probe the database-processing, filtering and aggregating it in various ways to investigate temperature variability over the Common Era. The unique approach to data stewardship and code-sharing employed here is designed to enable an unprecedented scale of investigation of the temperature history of the Common Era, by the scientific community and citizen-scientists alike

Quest for the 10^{10}He nucleus

The spectrum of $\rm ^He$ was studied by means of the $\rm ^He, p)^He$ reaction at a laboratory energy of 25 $\rm MeV/A$ and small center-of-mass angles. Missing mass spectrum of $\rm ^He$ was derived from the obtained p-8He coincidence. A resolution of 0.7 MeV was achieved in this spectrum for the measured $\rm ^He$ energy. Most likely, a well isolated group of 10 events detected between 2 and 5 MeV and showing a maximum at about 3 MeV in the spectrum of the present work exhibits the $\rm ^He$ g.s. resonance

New insights into the resonance states of 5^{5}H and 5^{5}He

International audienceThe $^{5}$H system was produced in the $^{3}$H(t, p) $^{5}$H reaction studied at small CM angles with a 58MeV tritium ion beam. High statistics data were used to reconstruct the energy and angular correlations between the $^{5}$H decay fragments. A broad structure in the $^{5}$H missing-mass spectrum showing up above 2.5MeV was identified as a mixture of the $3/2^+$ and $5/2^+$ states. The data also present an evidence that the $1/2^+$ ground state of $^{5}$H is located at about 2MeV. Then, the $^{5}$H and $^{5}$He systems were explored by means of transfer reactions occurring in the interactions of 132MeV $^{6}$He beam nuclei with deuterium. In the $^{2}$H( $^{6}$He, $^{3}$H) reaction a T = 3/2 isobaric analog state of $^{5}$H in $^{5}$He was observed at an excitation energy of 22.0±0.3MeV with a width of 2.5±0.3MeV

Correlation studies of the 5^{5}H spectrum

The nuclear system $^{5}$H was studied using the $^{3}$H($t$,$p$)$^{5}$H transfer reaction at a laboratory energy of 57.7 MeV and small center of mass angles. The energy and angular correlations among the $^{5}$H decay fragments were obtained by complete kinematical reconstruction. A broad structure in the $^{5}$H missing mass spectrum above 2.5 MeV with a typical width of several MeV was identified as a mixture of $3/2^+$ and $5/2^+$ states. Analysis of interference patterns observed in the measured angular correlations disclosed the $1/2^+$ ground state of $^{5}$H concealed in the smooth missing mass spectrum. The deduced values for the resonance energy and width are $E_{\text{g.s.}}\approx 1.8$ MeV and \Gamma_{\text{g.s.}\approx 1.3 MeV. The estimated cross sections for population of the ground state and the doublet of excited states at $\theta_{\text{c.m.}}=5^{\circ}-10^{circ}$ are $150\pm 50$ $\mu$b/sr and $4.6\pm 2$ mb/sr, respectively

Observation of Excited States in H 5

The excited states in the 5H system, which was produced in the 3H(t, p)5H reaction with a 58 MeV tritium beam at c.m. angles were investigated. The reconstruction of the energy and angular correlations between the 5H decay fragments was performed by using high statistics data. It was observed that a broad structure in the 5H missing mass spectrum above 2.5 MeV was identified as a mixture of the 3/2+ and 5/2+ states. The results show that the 3/2+ and 5/2+ states are either almost degenerate or the reaction mechanism causes a very specific interference of these states.SCOPUS: ar.jinfo:eu-repo/semantics/publishe