87 research outputs found

    Historical warming and climate sensitivity

    Get PDF
    In this dissertation, we study the climate sensitivity of the Earth. The climate sensitivity quantifies the response of the Earth system to radiative forcing, in particular, the radiative forcing induced by humans. We use both complex climate modelling and observations from the historical record for this endeavour. We analyse these data sources from the perspective of a conceptual framework based on the Earth’s energy budget. The foci of our study are on two wide topics. The first topic estimates how sensitive the Earth’s climate is to carbon dioxide using the historical warming. We use two quantities to measure the sensitivity: the transient climate response (TCR) and the long-term equilibrium climate sensitivity (ECS). Past studies analysed the historical observations of warming and forcing in the light of the Earth’s energy budget to estimate TCR and ECS. We ascertain that some of these calculations underestimate TCR and ECS. First, we analyse the disadvantages of past observational estimates concerning the uncertainties in the anthropogenic radiative forcing. Based on this analysis, we select the post-1970s period. Then we link the modelled warming in this period in complex climate models with the corresponding modelled TCR and ECS. This relationship between warming and sensitivity, and the observed post-1970s warming allow us to estimate TCR and ECS. Our TCR estimate is higher than the past estimates, and we find that this difference can be explained by past studies assuming that the ocean mixed-layer is equilibrated. Our ECS estimate is also higher than some past estimates and is in line with other studies that accounted for the effects of an evolving sea-surface temperature pattern. The evolving sea surface temperature pattern changes the feedback mechanisms on the warming and temporarily counteract the radiative forcing. The second topic explores the role of clouds in this temporary dampening of the transient global warming. We find that the cloud feedback not only acts directly with the sea surface temperature patterns that arise when the climate system is out of equilibrium, but clouds also affect other relevant feedback mechanisms. Past studies found that the evolving sea surface temperature pattern changes the radiative response between decadal and centennial timescales. A proposed mechanism connects clouds with the evolving pattern. They also show in observations the relationship between the decadal cloud variations and the corresponding variations in the radiative response of the Earth. Assisted by a complex climate model, we find that not only clouds link the evolving pattern with the radiative response, but also that they influence the remaining relevant mechanisms. To unravel the role of clouds, we use a cloud-locking technique which inhibits cloud feedback. We find that: a) clouds explain almost half of the difference in the radiative response between decadal and centennial timescales, and b) a synergy between cloud processes, lapse-rate and water-vapour feedback provides the tropical free-tropospheric warming that the proposed physical mechanism needs.In dieser Dissertation untersuchen wir die Klimasensitivität der Erde. Die Klimasensitivität misst die Reaktion des Erdsystems auf den Strahlungsantrieb unter besonderer Berücksichtigung des anthropogenen Strahlungantriebes. Dazu verwenden wir sowohl komplexe Klimamodelle, als auch historische Beobachtungen. Wir analysieren beide Datenquellen im physikalisch-konzeptuellen Rahmen des Wärmehaushaltes der Erde. Die Schwerpunkte unserer Untersuchung liegen auf zwei großen Themengebieten. Das erste Thema schätzt basierend auf der historischen Erwärmung ab wie sensibel das Klima der Erde auf Kohlendioxyd reagiert. Wir verwenden zwei Maße, um die Sensitivität zu messen: die kurzfristige emph{Transient Climate Response} (TCR) und die langfristige emph{Equilibrium Climate Sensitivity} (ECS). Vorherige Untersuchungen analysieren historische Beobachtungen der Erwärmung und des Strahlungsantriebes mit dem Wärmehaushalt der Erde, um die TCR und die ECS zu berechnen. Wir stellen fest, dass einige dieser früheren Berechnungen die TCR und die ECS unterschätzen. In dieser Dissertation analysieren wir zuerst die Nachteile dieser früheren Schätzungen in Bezug auf die Messunsicherheit des anthropogenen Strahlungsantriebs. Aufgrund der niedriegeren Messunsicherheit des anthropogenen Aerosolstrahlungsantriebes wählen wir für unsere Analyse den Zeitraum ab den 1970-iger Jahren aus. Dann verbinden wir die modellierte Erwärmung in diesem Zeitraum mit den entsprechenden modellierten TCRs und ECSs. Die ermittelte Beziehung zwischen Erwärmung und Sensitivität und die tatsächliche Erwärmung seit den 1970-iger Jahren macht eine neue Schätzungen der tatsächliche TCR und ECS möglich. Unsere Schätzung der TCR ist höher als die früheren Schätzungen. Wir stellen fest, dass der Unterschied auf eine Annahme vorheriger Schätzungen zurückführbar ist: Bezüglich des Wärmeaustausches ist der gutgemischte Ozean stationär. Unsere Schätzung der ECS ist ebenfalls höher als diejenigen einiger vorheriger Schätzungen. Unsere Schätzung stimmt mit anderen Schätzungen, die die Effekte eines sich entwickelnden Musters der Meeresoberlfächnetemperatur berücksichtigen, überein. Dieses Muster verändert die Rückkopplungsmechanismen und wirkt dem Strahlungsantrieb vorläufig entgegen. Das zweite Thema handelt von der Rolle der Wolken in dieser vorläufigen Dämpfung der transienten globalen Erwärmung. Wir entdecken, dass die Wolkenrückkopplung nicht nur eine direkte Wirkung hat, sondern auch, dass die Wolken andere relevante Rückkopplungen beeinflussen. Vorherige Untersuchungen stellten fest, dass das sich entwickelnde Muster der Meeresoberflächentemperatur die Strahlungsreaktion zwischen zehn- und hundertjährigen Zeitskalen verändert. Ein möglicher physikalischer Mechanismus, der die Wolken mit dem sich entwickelnden Muster verknüpft, wurde vorgeschlagen. Die Beziehung zwischen den zehnjährigen Schwankungen der Wolken und den entsprechenden Änderungen in der Strahlungsreaktion der Erde konnte bereits durch Beobachtungen verifiziert werden. Mit Hilfe eines komplexen Kimamodells finden wir, dass nicht nur die Wolken das sich entwickelnde Muster mit der Strahlungsreaktion verknüpfen, sondern auch, dass die Wolke die übrigen relevanten Mechanismen beeinflussen. Um die Rolle der Wolken zu untersuchen, verwenden wir eine ''cloud-locking'' Technik, die die Wolkenrückkopplung unterbindet. Unser Resultat ist: a) die Wolken erklären fast die Hälfte der Änderung der Strahlungsreaktion zwischen zehn- und hundertjährigen Zeitskalen und b) eine Synergie zwischen Wolkenprozessen, die Temperatur-Gradient- und die Wasserdampfrückkopplung liefert die tropische frei-troposphärische Erwärmung, die der vorgeschlagene physikalische Mechanismus benötigt

    Changes in the tropical lapse rate due to entrainment and their impact on climate sensitivity

    Get PDF
    The tropical temperature in the free troposphere deviates from a theoretical moist-adiabat. The overall deviations are attributed to the entrainment of dry surrounding air. The deviations gradually approach zero in the upper troposphere, which we explain with a buoyancy-sorting mechanism: the height to which individual convective parcels rise depends on parcel buoyancy, which is closely tied to the impact of entrainment during ascent. In higher altitudes, the temperature is increasingly controlled by the convective parcels that are warmer and more buoyant because of weaker entrainment effects. We represent such temperature deviations from moist-adiabats in a clear-sky one-dimensional radiative-convective equilibrium model. Compared with a moist-adiabatic adjustment, having the entrainment-induced temperature deviations lead to higher clear-sky climate sensitivity. As the impact of entrainment depends on the saturation deficit, which increases with warming, our model predicts even more amplified surface warming from entrainment in a warmer climate. © 2021. The Authors

    A longitudinal study of gene expression in first-episode schizophrenia; exploring relapse mechanisms by co-expression analysis in peripheral blood

    Get PDF
    Little is known about the pathophysiological mechanisms of relapse in first-episode schizophrenia, which limits the study of potential biomarkers. To explore relapse mechanisms and identify potential biomarkers for relapse prediction, we analyzed gene expression in peripheral blood in a cohort of first-episode schizophrenia patients with less than 5 years of evolution who had been evaluated over a 3-year follow-up period. A total of 91 participants of the 2EPs project formed the sample for baseline gene expression analysis. Of these, 67 provided biological samples at follow-up (36 after 3 years and 31 at relapse). Gene expression was assessed using the Clariom S Human Array. Weighted gene co-expression network analysis was applied to identify modules of co-expressed genes and to analyze their preservation after 3 years of follow-up or at relapse. Among the 25 modules identified, one module was semi-conserved at relapse (DarkTurquoise) and was enriched with risk genes for schizophrenia, showing a dysregulation of the TCF4 gene network in the module. Two modules were semi-conserved both at relapse and after 3 years of follow-up (DarkRed and DarkGrey) and were found to be biologically associated with protein modification and protein location processes. Higher expression of DarkRed genes was associated with higher risk of suffering a relapse and early appearance of relapse (p = 0.045). Our findings suggest that a dysregulation of the TCF4 network could be an important step in the biological process that leads to relapse and suggest that genes related to the ubiquitin proteosome system could be potential biomarkers of relapse. © 2021, The Author(s)

    Recommended temperature metrics for carbon budget estimates, model evaluation and climate policy

    Get PDF
    Recent estimates of the amount of carbon dioxide that can still be emitted while achieving the Paris Agreement temperature goals are larger than previously thought. One potential reason for these larger estimates may be the different temperature metrics used to estimate the observed global mean warming for the historical period, as they affect the size of the remaining carbon budget. Here we explain the reasons behind these remaining carbon budget increases, and discuss how methodological choices of the global mean temperature metric and the reference period influence estimates of the remaining carbon budget. We argue that the choice of the temperature metric should depend on the domain of application. For scientific estimates of total or remaining carbon budgets, globally averaged surface air temperature estimates should be used consistently for the past and the future. However, when used to inform the achievement of the Paris Agreement goal, a temperature metric consistent with the science that was underlying and directly informed the Paris Agreement should be applied. The resulting remaining carbon budgets should be calculated using the appropriate metric or adjusted to reflect these differences among temperature metrics. Transparency and understanding of the implications of such choices are crucial to providing useful information that can bridge the science–policy gap

    Performance study of a 3 x 1 x 1 m(3) dual phase liquid Argon Time Projection Chamber exposed to cosmic rays

    Get PDF
    This work would not have been possible without the support of the Swiss National Science Foundation, Switzerland; CEA and CNRS/IN2P3, France; KEK and the JSPS program, Japan; Ministerio de Ciencia e Innovacion in Spain under grants FPA2016-77347-C2, SEV-2016-0588 and MdM-2015-0509, Comunidad de Madrid, the CERCA program of the Generalitat de Catalunya and the fellowship (LCF/BQ/DI18/11660043) from "La Caixa" Foundation (ID 100010434); the Programme PNCDI III, CERN-RO, under Contract 2/2020, Romania; the U.S. Department of Energy under Grant No. DE-SC0011686. This project has received funding from the European Union's Horizon 2020 Research and Innovation program under Grant Agreement no. 654168. The authors are also grateful to the French government operated by the National Research Agency (ANR) for the LABEX Enigmass, LABEX Lyon Institute of Origins (ANR-10-LABX-0066) of the Universite de Lyon for its financial support within the program "Investissements d'Avenir" (ANR-11-IDEX-0007).We report the results of the analyses of the cosmic ray data collected with a 4 tonne (3x1x1 m(3)) active mass (volume) Liquid Argon Time-Projection Chamber (TPC) operated in a dual-phase mode. We present a detailed study of the TPC's response, its main detector parameters and performance. The results are important for the understanding and further developments of the dual-phase technology, thanks to the verification of key aspects, such as the extraction of electrons from liquid to gas and their amplification through the entire one square metre readout plain, gain stability, purity and charge sharing between readout views.Swiss National Science Foundation (SNSF)French Atomic Energy CommissionCentre National de la Recherche Scientifique (CNRS)High Energy Accelerator Research Organization (KEK)Ministry of Education, Culture, Sports, Science and Technology, Japan (MEXT)Japan Society for the Promotion of ScienceSpanish Government FPA2016-77347-C2 SEV-2016-0588MdM-2015-0509Comunidad de MadridCERCA program of the Generalitat de CatalunyaLa Caixa Foundation LCF/BQ/DI18/11660043 100010434Programme PNCDI III, RomaniaCERN-RO, Romania 2/2020United States Department of Energy (DOE) SC0011686European Commission 654168Universite de Lyon ANR-10-LABX-0066 ANR-11-IDEX-000

    The CARMENES search for exoplanets around M dwarfs. Two temperate Earth-mass planet candidates around Teegarden’s Star

    Get PDF
    Context.Teegarden’s Star is the brightest and one of the nearest ultra-cool dwarfs in the solar neighbourhood. For its late spectral type (M7.0 V),the star shows relatively little activity and is a prime target for near-infrared radial velocity surveys such as CARMENES.Aims.As part of the CARMENES search for exoplanets around M dwarfs, we obtained more than 200 radial-velocity measurements of Teegarden’sStar and analysed them for planetary signals.Methods.We find periodic variability in the radial velocities of Teegarden’s Star. We also studied photometric measurements to rule out stellarbrightness variations mimicking planetary signals.Results.We find evidence for two planet candidates, each with 1.1M⊕minimum mass, orbiting at periods of 4.91 and 11.4 d, respectively. Noevidence for planetary transits could be found in archival and follow-up photometry. Small photometric variability is suggestive of slow rotationand old age.Conclusions.The two planets are among the lowest-mass planets discovered so far, and they are the first Earth-mass planets around an ultra-cooldwarf for which the masses have been determined using radial velocities.We thank the referee Rodrigo Díaz for a careful review andhelpful comments. M.Z. acknowledges support from the Deutsche Forschungs-gemeinschaft under DFG RE 1664/12-1 and Research Unit FOR2544 “BluePlanets around Red Stars”, project no. RE 1664/14-1. CARMENES isan instrument for the Centro Astronómico Hispano-Alemán de Calar Alto(CAHA, Almería, Spain). CARMENES is funded by the German Max-Planck-Gesellschaft (MPG), the Spanish Consejo Superior de InvestigacionesCientíficas (CSIC), the European Union through FEDER/ERF FICTS-2011-02 funds, and the members of the CARMENES Consortium (Max-Planck-Institut für Astronomie, Instituto de Astrofísica de Andalucía, LandessternwarteKönigstuhl, Institut de Ciències de l’Espai, Institut für Astrophysik Göttingen,Universidad Complutense de Madrid, Thüringer Landessternwarte Tautenburg,Instituto de Astrofísica de Canarias, Hamburger Sternwarte, Centro de Astro-biología and Centro Astronómico Hispano-Alemán), with additional contribu-tions by the Spanish Ministry of Economy, the German Science Foundationthrough the Major Research Instrumentation Programme and DFG ResearchUnit FOR2544 “Blue Planets around Red Stars”, the Klaus Tschira Stiftung, thestates of Baden-Württemberg and Niedersachsen, and by the Junta de Andalucía.Based on data from the CARMENES data archive at CAB (INTA-CSIC). Thisarticle is based on observations made with the MuSCAT2 instrument, devel-oped by ABC, at Telescopio Carlos Sánchez operated on the island of Tener-ife by the IAC in the Spanish Observatorio del Teide. Data were partly col-lected with the 150-cm and 90-cm telescopes at the Sierra Nevada Observa-tory (SNO) operated by the Instituto de Astrofísica de Andalucía (IAA-CSIC).Data were partly obtained with the MONET/South telescope of the MOnitoringNEtwork of Telescopes, funded by the Alfried Krupp von Bohlen und HalbachFoundation, Essen, and operated by the Georg-August-Universität Göttingen,the McDonald Observatory of the University of Texas at Austin, and the SouthAfrican Astronomical Observatory. We acknowledge financial support from theSpanish Agencia Estatal de Investigación of the Ministerio de Ciencia, Inno-vación y Universidades and the European FEDER/ERF funds through projectsAYA2015-69350-C3-2-P, AYA2016-79425-C3-1/2/3-P, AYA2018-84089, BES-2017-080769, BES-2017-082610, ESP2015-65712-C5-5-R, ESP2016-80435-C2-1/2-R, ESP2017-87143-R, ESP2017-87676-2-2, ESP2017-87676-C5-1/2/5-R, FPU15/01476, RYC-2012-09913, the Centre of Excellence ”Severo Ochoa”and ”María de Maeztu” awards to the Instituto de Astrofísica de Canarias (SEV-2015-0548), Instituto de Astrofísica de Andalucía (SEV-2017-0709), and Cen-tro de Astrobiología (MDM-2017-0737), the Generalitat de Catalunya throughCERCA programme”, the Deutsches Zentrum für Luft- und Raumfahrt throughgrants 50OW0204 and 50OO1501, the European Research Council through grant694513, the Italian Ministero dell’instruzione, dell’università de della ricerca andUniversità degli Studi di Roma Tor Vergata through FFABR 2017 and “Mis-sion: Sustainability 2016”, the UK Science and Technology Facilities Council through grant ST/P000592/1, the Israel Science Foundation through grant848/16, the Chilean CONICYT-FONDECYT through grant 3180405, the Mexi-can CONACYT through grant CVU 448248, the JSPS KAKENHI through grantsJP18H01265 and 18H05439, and the JST PRESTO through grant JPMJPR1775

    Effectiveness of an intervention for improving drug prescription in primary care patients with multimorbidity and polypharmacy:Study protocol of a cluster randomized clinical trial (Multi-PAP project)

    Get PDF
    This study was funded by the Fondo de Investigaciones Sanitarias ISCIII (Grant Numbers PI15/00276, PI15/00572, PI15/00996), REDISSEC (Project Numbers RD12/0001/0012, RD16/0001/0005), and the European Regional Development Fund ("A way to build Europe").Background: Multimorbidity is associated with negative effects both on people's health and on healthcare systems. A key problem linked to multimorbidity is polypharmacy, which in turn is associated with increased risk of partly preventable adverse effects, including mortality. The Ariadne principles describe a model of care based on a thorough assessment of diseases, treatments (and potential interactions), clinical status, context and preferences of patients with multimorbidity, with the aim of prioritizing and sharing realistic treatment goals that guide an individualized management. The aim of this study is to evaluate the effectiveness of a complex intervention that implements the Ariadne principles in a population of young-old patients with multimorbidity and polypharmacy. The intervention seeks to improve the appropriateness of prescribing in primary care (PC), as measured by the medication appropriateness index (MAI) score at 6 and 12months, as compared with usual care. Methods/Design: Design:pragmatic cluster randomized clinical trial. Unit of randomization: family physician (FP). Unit of analysis: patient. Scope: PC health centres in three autonomous communities: Aragon, Madrid, and Andalusia (Spain). Population: patients aged 65-74years with multimorbidity (≥3 chronic diseases) and polypharmacy (≥5 drugs prescribed in ≥3months). Sample size: n=400 (200 per study arm). Intervention: complex intervention based on the implementation of the Ariadne principles with two components: (1) FP training and (2) FP-patient interview. Outcomes: MAI score, health services use, quality of life (Euroqol 5D-5L), pharmacotherapy and adherence to treatment (Morisky-Green, Haynes-Sackett), and clinical and socio-demographic variables. Statistical analysis: primary outcome is the difference in MAI score between T0 and T1 and corresponding 95% confidence interval. Adjustment for confounding factors will be performed by multilevel analysis. All analyses will be carried out in accordance with the intention-to-treat principle. Discussion: It is essential to provide evidence concerning interventions on PC patients with polypharmacy and multimorbidity, conducted in the context of routine clinical practice, and involving young-old patients with significant potential for preventing negative health outcomes. Trial registration: Clinicaltrials.gov, NCT02866799Publisher PDFPeer reviewe

    Erratum: The Belle II Physics Book (Progress of Theoretical and Experimental Physics (2019) 2019 (123C01) DOI: 10.1093/ptep/ptz106)

    Get PDF

    Measurements of the branching fractions for BKγB \to K^{*}\gamma decays at Belle II

    Get PDF
    This paper reports a study of BKγB \to K^{*}\gamma decays using 62.8±0.662.8\pm 0.6 fb1^{-1} of data collected during 2019--2020 by the Belle II experiment at the SuperKEKB e+ee^{+}e^{-} asymmetric-energy collider, corresponding to (68.2±0.8)×106(68.2 \pm 0.8) \times 10^6 BBB\overline{B} events. We find 454±28454 \pm 28, 50±1050 \pm 10, 169±18169 \pm 18, and 160±17160 \pm 17 signal events in the decay modes B0K0[K+π]γB^{0} \to K^{*0}[K^{+}\pi^{-}]\gamma, B0K0[KS0π0]γB^{0} \to K^{*0}[K^0_{\rm S}\pi^{0}]\gamma, B+K+[K+π0]γB^{+} \to K^{*+}[K^{+}\pi^{0}]\gamma, and B+K+[K+π0]γB^{+} \to K^{*+}[K^{+}\pi^{0}]\gamma, respectively. The uncertainties quoted for the signal yield are statistical only. We report the branching fractions of these decays: B[B0K0[K+π]γ]=(4.5±0.3±0.2)×105,\mathcal{B} [B^{0} \to K^{*0}[K^{+}\pi^{-}]\gamma] = (4.5 \pm 0.3 \pm 0.2) \times 10^{-5}, B[B0K0[KS0π0]γ]=(4.4±0.9±0.6)×105,\mathcal{B} [B^{0} \to K^{*0}[K^0_{\rm S}\pi^{0}]\gamma] = (4.4 \pm 0.9 \pm 0.6) \times 10^{-5}, B[B+K+[K+π0]γ]=(5.0±0.5±0.4)×105, and\mathcal{B} [B^{+} \to K^{*+}[K^{+}\pi^{0}]\gamma] = (5.0 \pm 0.5 \pm 0.4)\times 10^{-5},\text{ and} B[B+K+[KS0π+]γ]=(5.4±0.6±0.4)×105,\mathcal{B} [B^{+} \to K^{*+}[K^0_{\rm S}\pi^{+}]\gamma] = (5.4 \pm 0.6 \pm 0.4) \times 10^{-5}, where the first uncertainty is statistical, and the second is systematic. The results are consistent with world-average values

    The Belle II Physics Book

    Get PDF
    We present the physics program of the Belle II experiment, located on the intensity frontier SuperKEKB e+ee^+e^- collider. Belle II collected its first collisions in 2018, and is expected to operate for the next decade. It is anticipated to collect 50/ab of collision data over its lifetime. This book is the outcome of a joint effort of Belle II collaborators and theorists through the Belle II theory interface platform (B2TiP), an effort that commenced in 2014. The aim of B2TiP was to elucidate the potential impacts of the Belle II program, which includes a wide scope of physics topics: B physics, charm, tau, quarkonium, electroweak precision measurements and dark sector searches. It is composed of nine working groups (WGs), which are coordinated by teams of theorist and experimentalists conveners: Semileptonic and leptonic B decays, Radiative and Electroweak penguins, phi_1 and phi_2 (time-dependent CP violation) measurements, phi_3 measurements, Charmless hadronic B decay, Charm, Quarkonium(like), tau and low-multiplicity processes, new physics and global fit analyses. This book highlights "golden- and silver-channels", i.e. those that would have the highest potential impact in the field. Theorists scrutinised the role of those measurements and estimated the respective theoretical uncertainties, achievable now as well as prospects for the future. Experimentalists investigated the expected improvements with the large dataset expected from Belle II, taking into account improved performance from the upgraded detector.Comment: 689 page
    corecore