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Nabiei F, Badro J, Boukaré C, Hébert C, Cantoni M, Borensztajn S, Wehr N, Gillet P. Investigating Magma Ocean Solidification on Earth Through Laser-Heated Diamond Anvil Cell Experiments. Geophys Res Lett 2021; 48:e2021GL092446. [PMID: 34219835 PMCID: PMC8244043 DOI: 10.1029/2021gl092446] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 05/18/2021] [Accepted: 05/22/2021] [Indexed: 05/09/2023]
Abstract
We carried out a series of silicate fractional crystallization experiments at lower mantle pressures using the laser-heated diamond anvil cell. Phase relations and the compositional evolution of the cotectic melt and equilibrium solids along the liquid line of descent were determined and used to assemble the melting phase diagram. In a pyrolitic magma ocean, the first mineral to crystallize in the deep mantle is iron-depleted calcium-bearing bridgmanite. From the phase diagram, we estimate that the initial 33%-36% of the magma ocean will crystallize to form such a buoyant bridgmanite. Substantial calcium solubility in bridgmanite is observed up to 129 GPa, and significantly delays the crystallization of the calcium silicate perovskite phase during magma ocean solidification. Residual melts are strongly iron-enriched as crystallization proceeds, making them denser than any of the coexisting solids at deep mantle conditions, thus supporting the terrestrial basal magma ocean hypothesis (Labrosse et al., 2007).
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Affiliation(s)
- Farhang Nabiei
- Earth and Planetary Science LaboratoryEPFLLausanneSwitzerland
- Electron Spectrometry and Microscopy LaboratoryEPFLLausanneSwitzerland
| | - James Badro
- Earth and Planetary Science LaboratoryEPFLLausanneSwitzerland
- Université de ParisInstitut de Physique du Globe de ParisCNRSParisFrance
| | - Charles‐Édouard Boukaré
- Earth and Planetary Science LaboratoryEPFLLausanneSwitzerland
- Université de ParisInstitut de Physique du Globe de ParisCNRSParisFrance
| | - Cécile Hébert
- Electron Spectrometry and Microscopy LaboratoryEPFLLausanneSwitzerland
| | - Marco Cantoni
- Interdisciplinary Centre for Electron MicroscopyEPFLLausanneSwitzerland
| | | | - Nicolas Wehr
- Université de ParisInstitut de Physique du Globe de ParisCNRSParisFrance
| | - Philippe Gillet
- Earth and Planetary Science LaboratoryEPFLLausanneSwitzerland
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2
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Dixit V, Nuijens L, Helfer KC. Counter-Gradient Momentum Transport Through Subtropical Shallow Convection in ICON-LEM Simulations. J Adv Model Earth Syst 2021; 13:e2020MS002352. [PMID: 34221242 PMCID: PMC8244060 DOI: 10.1029/2020ms002352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/25/2020] [Revised: 04/28/2021] [Accepted: 05/04/2021] [Indexed: 06/13/2023]
Abstract
It is well known that subtropical shallow convection transports heat and water vapor upwards from the surface. It is less clear if it also transports horizontal momentum upwards to significantly affect the trade winds in which it is embedded. We utilize unique multiday large-eddy simulations run over the tropical Atlantic with ICON-LEM to investigate the character of shallow convective momentum transport (CMT). For a typical trade-wind profile during boreal winter, CMT acts as an apparent friction to decelerate the north-easterly flow. This effect maximizes below the cloud base while in the cloud layer, friction is very small, although present over a relatively deep layer. In the cloud layer, the zonal component of the momentum flux is counter-gradient and penetrates deeper than reported in traditional shallow cumulus LES cases. The transport through conditionally sampled convective updrafts and downdrafts explains a weak friction effect, but not the counter-gradient flux near the cloud tops. The analysis of the momentum flux budget reveals that, in the cloud layer, the counter-gradient flux is driven by convectively triggered nonhydrostatic pressure-gradients and horizontal circulations surrounding the clouds. A model set-up with large domain size and realistic boundary conditions is necessary to resolve these effects.
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Affiliation(s)
- Vishal Dixit
- Department of Remote Sensing and GeosciencesTU DelftDelftthe Netherlands
| | - Louise Nuijens
- Department of Remote Sensing and GeosciencesTU DelftDelftthe Netherlands
| | - Kevin C. Helfer
- Department of Remote Sensing and GeosciencesTU DelftDelftthe Netherlands
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3
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Zareidarmiyan A, Parisio F, Makhnenko RY, Salarirad H, Vilarrasa V. How Equivalent Are Equivalent Porous Media? Geophys Res Lett 2021; 48:e2020GL089163. [PMID: 34219842 PMCID: PMC8243940 DOI: 10.1029/2020gl089163] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Revised: 03/30/2021] [Accepted: 04/04/2021] [Indexed: 06/13/2023]
Abstract
Geoenergy and geoengineering applications usually involve fluid injection into and production from fractured media. Accounting for fractures is important because of the strong poromechanical coupling that ties pore pressure changes and deformation. A possible approach to the problem uses equivalent porous media to reduce the computational cost and model complexity instead of explicitly including fractures in the models. We investigate the validity of this simplification by comparing these two approaches. Simulation results show that pore pressure distribution significantly differs between the two approaches even when both are calibrated to predict identical values at the injection and production wells. Additionally, changes in fracture stability are not well captured with the equivalent porous medium. We conclude that explicitly accounting for fractures in numerical models may be necessary under some circumstances to perform reliable coupled thermohydromechanical simulations, which could be used in conjunction with other tools for induced seismicity forecasting.
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Affiliation(s)
- Ahmad Zareidarmiyan
- Department of Mining and Metallurgical EngineeringAmirkabir University of Technology—Tehran Polytechnic (AUT)TehranIran
- Institute of Environmental Assessment and Water Research (IDAEA)Spanish National Research Council (CSIC)BarcelonaSpain
- Associated Unit: Hydrogeology Group UPC‐CSICBarcelonaSpain
| | - Francesco Parisio
- Chair of Soil Mechanics and Foundation EngineeringFreiberg University of Mining and TechnologyFreibergGermany
| | - Roman Y. Makhnenko
- Department of Civil and Environmental EngineeringUniversity of Illinois at Urbana‐ChampaignUrbanaUSA
| | - Hossein Salarirad
- Department of Mining and Metallurgical EngineeringAmirkabir University of Technology—Tehran Polytechnic (AUT)TehranIran
| | - Victor Vilarrasa
- Institute of Environmental Assessment and Water Research (IDAEA)Spanish National Research Council (CSIC)BarcelonaSpain
- Associated Unit: Hydrogeology Group UPC‐CSICBarcelonaSpain
- Mediterranean Institute for Advanced Studies (IMEDEA)Spanish National Research Council (CSIC)Balearic IslandsSpain
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4
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Bernasconi SM, Daëron M, Bergmann KD, Bonifacie M, Meckler AN, Affek HP, Anderson N, Bajnai D, Barkan E, Beverly E, Blamart D, Burgener L, Calmels D, Chaduteau C, Clog M, Davidheiser‐Kroll B, Davies A, Dux F, Eiler J, Elliott B, Fetrow AC, Fiebig J, Goldberg S, Hermoso M, Huntington KW, Hyland E, Ingalls M, Jaggi M, John CM, Jost AB, Katz S, Kelson J, Kluge T, Kocken IJ, Laskar A, Leutert TJ, Liang D, Lucarelli J, Mackey TJ, Mangenot X, Meinicke N, Modestou SE, Müller IA, Murray S, Neary A, Packard N, Passey BH, Pelletier E, Petersen S, Piasecki A, Schauer A, Snell KE, Swart PK, Tripati A, Upadhyay D, Vennemann T, Winkelstern I, Yarian D, Yoshida N, Zhang N, Ziegler M. InterCarb: A Community Effort to Improve Interlaboratory Standardization of the Carbonate Clumped Isotope Thermometer Using Carbonate Standards. Geochem Geophys Geosyst 2021; 22:e2020GC009588. [PMID: 34220359 PMCID: PMC8244079 DOI: 10.1029/2020gc009588] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 03/18/2021] [Accepted: 03/19/2021] [Indexed: 06/12/2023]
Abstract
Increased use and improved methodology of carbonate clumped isotope thermometry has greatly enhanced our ability to interrogate a suite of Earth-system processes. However, interlaboratory discrepancies in quantifying carbonate clumped isotope (Δ47) measurements persist, and their specific sources remain unclear. To address interlaboratory differences, we first provide consensus values from the clumped isotope community for four carbonate standards relative to heated and equilibrated gases with 1,819 individual analyses from 10 laboratories. Then we analyzed the four carbonate standards along with three additional standards, spanning a broad range of δ47 and Δ47 values, for a total of 5,329 analyses on 25 individual mass spectrometers from 22 different laboratories. Treating three of the materials as known standards and the other four as unknowns, we find that the use of carbonate reference materials is a robust method for standardization that yields interlaboratory discrepancies entirely consistent with intralaboratory analytical uncertainties. Carbonate reference materials, along with measurement and data processing practices described herein, provide the carbonate clumped isotope community with a robust approach to achieve interlaboratory agreement as we continue to use and improve this powerful geochemical tool. We propose that carbonate clumped isotope data normalized to the carbonate reference materials described in this publication should be reported as Δ47 (I-CDES) values for Intercarb-Carbon Dioxide Equilibrium Scale.
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Affiliation(s)
| | - M. Daëron
- Laboratoire des Sciences du Climat et de l’EnvironnementLSCE/IPSLCEA‐CNRS‐UVSQUniversité Paris‐SaclayGif‐sur‐YvetteFrance
| | - K. D. Bergmann
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridgeMAUSA
| | - M. Bonifacie
- Université de ParisInstitut de Physique du Globe de ParisCNRSParisFrance
| | - A. N. Meckler
- Bjerknes Centre for Climate Research and Department of Earth ScienceUniversity of BergenBergenNorway
| | - H. P. Affek
- Institute of Earth SciencesHebrew University of JerusalemJerusalemIsrael
| | - N. Anderson
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridgeMAUSA
| | - D. Bajnai
- Institute of GeosciencesGoethe University FrankfurtFrankfurt am MainGermany
| | - E. Barkan
- Institute of Earth SciencesHebrew University of JerusalemJerusalemIsrael
| | - E. Beverly
- Now at Department of Earth and Atmospheric SciencesUniversity of HoustonHoustonTXUSA
- Department of Earth and Environmental SciencesUniversity of MichiganAnn ArborMIUSA
| | - D. Blamart
- Laboratoire des Sciences du Climat et de l’EnvironnementLSCE/IPSLCEA‐CNRS‐UVSQUniversité Paris‐SaclayGif‐sur‐YvetteFrance
| | - L. Burgener
- Department of Marine, Earth and Atmospheric SciencesNorth Carolina State UniversityRaleighNCUSA
| | - D. Calmels
- Université de ParisInstitut de Physique du Globe de ParisCNRSParisFrance
- Now at Geosciences Paris Sud (GEOPS)Université Paris‐SaclayCNRSOrsayFrance
| | - C. Chaduteau
- Université de ParisInstitut de Physique du Globe de ParisCNRSParisFrance
| | - M. Clog
- Scottish Universities Environmental Research Centre (SUERC)ScotlandUK
| | | | - A. Davies
- Now at Stockholm UniversityStockholmSweden
- Imperial CollegeLondonUK
| | - F. Dux
- Now at School of Earth and Life SciencesUniversity of WollongongWollongongAustralia
- School of GeographyUniversity of MelbourneMelbourneAustralia
| | - J. Eiler
- Geological and Planetary SciencesCalifornia Institute of TechnologyPasadenaCAUSA
| | - B. Elliott
- Department of Earth, Planetary, and Space SciencesUniversity of California Los AngelesLos AngelesCAUSA
| | | | - J. Fiebig
- Institute of GeosciencesGoethe University FrankfurtFrankfurt am MainGermany
| | - S. Goldberg
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridgeMAUSA
| | - M. Hermoso
- Université de ParisInstitut de Physique du Globe de ParisCNRSParisFrance
- Univ. Littoral Côte d’OpaleUniv. LilleCNRSLaboratoire d’Océanologie et de Géosciences (UMR 8187 LOG)WimereuxFrance
| | | | - E. Hyland
- Department of Marine, Earth and Atmospheric SciencesNorth Carolina State UniversityRaleighNCUSA
| | - M. Ingalls
- Geological and Planetary SciencesCalifornia Institute of TechnologyPasadenaCAUSA
- Now at Department of GeosciencesThe Pennsylvania State UniversityUniversity ParkPAUSA
| | - M. Jaggi
- Geological InstituteETH ZürichZürichSwitzerland
| | | | - A. B. Jost
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridgeMAUSA
| | - S. Katz
- Department of Earth and Environmental SciencesUniversity of MichiganAnn ArborMIUSA
| | - J. Kelson
- Department of Earth and Environmental SciencesUniversity of MichiganAnn ArborMIUSA
| | - T. Kluge
- Imperial CollegeLondonUK
- Now at Karlsruher Institut für Technologie KITKarlsruheGermany
| | - I. J. Kocken
- Department of Earth SciencesUniversity of UtrechtUtrechtThe Netherlands
| | - A. Laskar
- Institute of Earth SciencesAcademia SinicaTaipeiTaiwan
| | - T. J. Leutert
- Bjerknes Centre for Climate Research and Department of Earth ScienceUniversity of BergenBergenNorway
- Now at Max Planck Institute for ChemistryMainzGermany
| | - D. Liang
- Institute of Earth SciencesAcademia SinicaTaipeiTaiwan
| | - J. Lucarelli
- Department of Earth, Planetary, and Space SciencesUniversity of California Los AngelesLos AngelesCAUSA
| | - T. J. Mackey
- Department of Earth, Atmospheric and Planetary SciencesMassachusetts Institute of TechnologyCambridgeMAUSA
- Now at Department of Earth and Planetary SciencesUniversity of New MexicoAlbuquerqueNMUSA
| | - X. Mangenot
- Université de ParisInstitut de Physique du Globe de ParisCNRSParisFrance
- Geological and Planetary SciencesCalifornia Institute of TechnologyPasadenaCAUSA
| | - N. Meinicke
- Bjerknes Centre for Climate Research and Department of Earth ScienceUniversity of BergenBergenNorway
| | - S. E. Modestou
- Bjerknes Centre for Climate Research and Department of Earth ScienceUniversity of BergenBergenNorway
| | - I. A. Müller
- Department of Earth SciencesUniversity of UtrechtUtrechtThe Netherlands
| | | | - A. Neary
- Department of Earth and Environmental SciencesUniversity of MichiganAnn ArborMIUSA
| | - N. Packard
- Department of Earth and Environmental SciencesUniversity of MichiganAnn ArborMIUSA
| | - B. H. Passey
- Department of Earth and Environmental SciencesUniversity of MichiganAnn ArborMIUSA
| | - E. Pelletier
- Department of Earth and Environmental SciencesUniversity of MichiganAnn ArborMIUSA
| | - S. Petersen
- Department of Earth and Environmental SciencesUniversity of MichiganAnn ArborMIUSA
| | - A. Piasecki
- Bjerknes Centre for Climate Research and Department of Earth ScienceUniversity of BergenBergenNorway
- Now at Department of Earth SciencesDartmouth CollegeHanoverNHUSA
| | | | | | - P. K. Swart
- Department of Marine GeosciencesRostiel School of Marine and Atmospheric SciencesUniversity of MiamiMiamiFLUSA
| | - A. Tripati
- Department of Earth, Planetary, and Space SciencesUniversity of California Los AngelesLos AngelesCAUSA
| | - D. Upadhyay
- Department of Earth, Planetary, and Space SciencesUniversity of California Los AngelesLos AngelesCAUSA
| | - T. Vennemann
- Institute of Earth Surface DynamicsUniversity of LausanneLausanneSwitzerland
| | - I. Winkelstern
- Department of Earth and Environmental SciencesUniversity of MichiganAnn ArborMIUSA
- Now at Geology DepartmentGrand Valley State UniversityAllendaleMIUSA
| | - D. Yarian
- Department of Earth and Environmental SciencesUniversity of MichiganAnn ArborMIUSA
| | - N. Yoshida
- Earth‐Life Science InstituteTokyo Institute of TechnologyTokyoJapan
- National Institute of Information and Communications TechnologyTokyoJapan
| | - N. Zhang
- Earth‐Life Science InstituteTokyo Institute of TechnologyTokyoJapan
| | - M. Ziegler
- Department of Earth SciencesUniversity of UtrechtUtrechtThe Netherlands
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5
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Parracho AC, Safieddine S, Lezeaux O, Clarisse L, Whitburn S, George M, Prunet P, Clerbaux C. IASI-Derived Sea Surface Temperature Data Set for Climate Studies. Earth Space Sci 2021; 8:e2020EA001427. [PMID: 34222560 PMCID: PMC8243959 DOI: 10.1029/2020ea001427] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 03/10/2021] [Accepted: 03/22/2021] [Indexed: 06/13/2023]
Abstract
Sea surface temperature (SST) is an essential climate variable, that is directly used in climate monitoring. Although satellite measurements can offer continuous global coverage, obtaining a long-term homogeneous satellite-derived SST data set suitable for climate studies based on a single instrument is still a challenge. In this work, we assess a homogeneous SST data set derived from reprocessed Infrared Atmospheric Sounding Interferometer (IASI) level-1 (L1C) radiance data. The SST is computed using Planck's Law and simple atmospheric corrections. We assess the data set using the ERA5 reanalysis and the EUMETSAT-released IASI level-2 SST product. Over the entire period, the reprocessed IASI SST shows a mean global difference with ERA5 close to zero, a mean absolute bias under 0.5°C, with a SD of difference around 0.3°C and a correlation coefficient over 0.99. In addition, the reprocessed data set shows a stable bias and SD, which is an advantage for climate studies. The interannual variability and trends were compared with other SST data sets: ERA5, Hadley Centre's SST (HadISST), and NOAA's Optimal Interpolation SST Analysis (OISSTv2). We found that the reprocessed SST data set is able to capture the patterns of interannual variability well, showing the same areas of high interannual variability (>1.5°C), including over the tropical Pacific in January corresponding to the El Niño Southern Oscillation. Although the period studied is relatively short, we demonstrate that the IASI data set reproduces the same trend patterns found in the other data sets (i.e., cooling trend in the North Atlantic, warming trend over the Mediterranean).
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Affiliation(s)
| | | | | | - Lieven Clarisse
- Spectroscopy, Quantum Chemistry and Atmospheric Remote Sensing (SQUARES)Université Libre de Bruxelles (ULB)BrusselsBelgium
| | - Simon Whitburn
- Spectroscopy, Quantum Chemistry and Atmospheric Remote Sensing (SQUARES)Université Libre de Bruxelles (ULB)BrusselsBelgium
| | - Maya George
- LATMOS/IPSLUVSQCNRSSorbonne UniversitéParisFrance
| | | | - Cathy Clerbaux
- LATMOS/IPSLUVSQCNRSSorbonne UniversitéParisFrance
- Spectroscopy, Quantum Chemistry and Atmospheric Remote Sensing (SQUARES)Université Libre de Bruxelles (ULB)BrusselsBelgium
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6
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Lauderdale JM, Cael BB. Impact of Remineralization Profile Shape on the Air-Sea Carbon Balance. Geophys Res Lett 2021; 48:e2020GL091746. [PMID: 34219838 PMCID: PMC8243937 DOI: 10.1029/2020gl091746] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/16/2020] [Revised: 03/11/2021] [Accepted: 03/15/2021] [Indexed: 06/13/2023]
Abstract
The ocean's "biological pump" significantly modulates atmospheric carbon dioxide levels. However, the complexity and variability of processes involved introduces uncertainty in interpretation of transient observations and future climate projections. Much research has focused on "parametric uncertainty," particularly determining the exponent(s) of a power-law relationship of sinking particle flux with depth. Varying this relationship's functional form introduces additional "structural uncertainty." We use an ocean biogeochemistry model substituting six alternative remineralization profiles fit to a reference power-law curve, to systematically characterize structural uncertainty, which, in atmospheric pCO2 terms, is roughly 50% of parametric uncertainty associated with varying the power-law exponent within its plausible global range, and similar to uncertainty associated with regional variation in power-law exponents. The substantial contribution of structural uncertainty to total uncertainty highlights the need to improve characterization of biological pump processes, and compare the performance of different profiles within Earth System Models to obtain better constrained climate projections.
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Affiliation(s)
| | - B. B. Cael
- Ocean BiogeosciencesNational Oceanography CentreSouthamptonUK
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7
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Triana SA, Trinh A, Rekier J, Zhu P, Dehant V. The Viscous and Ohmic Damping of the Earth's Free Core Nutation. J Geophys Res Solid Earth 2021; 126:e2020JB021042. [PMID: 34221788 PMCID: PMC8244021 DOI: 10.1029/2020jb021042] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 02/23/2021] [Accepted: 03/04/2021] [Indexed: 06/13/2023]
Abstract
The cause for the damping of the Earth's free core nutation (FCN) and the free inner core nutation eigenmodes has been a matter of debate since the earliest reliable estimations from nutation observations were made available. Numerical studies are difficult given the extreme values of some of the parameters associated with the Earth's fluid outer core, where important energy dissipation mechanisms can take place. We present a fully 3D numerical model for the FCN capable of describing accurately viscous and Ohmic dissipation processes taking place in the bulk of the fluid core as well as in the boundary layers. We find an asymptotic regime, appropriate for Earth's parameters, where viscous and Ohmic processes contribute to the total damping, with the dissipation taking place almost exclusively in the boundary layers. By matching the observed nutational damping, we infer an enhanced effective viscosity matching and validating methods from previous studies. We suggest that turbulence caused by the Earth's precession can be a source for the enhanced viscosity.
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Affiliation(s)
| | - Antony Trinh
- Lunar and Planetary LaboratoryUniversity of ArizonaTucsonAZUSA
| | - Jérémy Rekier
- Reference Systems and PlanetologyRoyal Observatory of BelgiumBrusselsBelgium
| | - Ping Zhu
- Reference Systems and PlanetologyRoyal Observatory of BelgiumBrusselsBelgium
| | - Véronique Dehant
- Reference Systems and PlanetologyRoyal Observatory of BelgiumBrusselsBelgium
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8
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Lobelle D, Kooi M, Koelmans AA, Laufkötter C, Jongedijk CE, Kehl C, van Sebille E. Global Modeled Sinking Characteristics of Biofouled Microplastic. J Geophys Res Oceans 2021; 126:e2020JC017098. [PMID: 34221786 PMCID: PMC8243974 DOI: 10.1029/2020jc017098] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/19/2021] [Accepted: 03/17/2021] [Indexed: 05/28/2023]
Abstract
Microplastic debris ending up at the sea surface has become a known major environmental issue. However, how microplastic particles move and when they sink in the ocean remains largely unknown. Here, we model microplastic subject to biofouling (algal growth on a substrate) to estimate sinking timescales and the time to reach the depth where particles stop sinking. We combine NEMO-MEDUSA 2.0 output, that represents hydrodynamic and biological properties of seawater, with a particle-tracking framework. Different sizes and densities of particles (for different types of plastic) are simulated, showing that the global distribution of sinking timescales is largely size-dependent as opposed to density-dependent. The smallest particles we simulate (0.1 μm) start sinking almost immediately around the globe and their trajectories take the longest time to reach their first sinking depth (relative to larger particles). In oligotrophic subtropical gyres with low algal concentrations, particles between 1 and 0.01 mm do not sink within the simulation time of 90 days. This suggests that in addition to the comparatively well-known physical processes, biological processes might also contribute to the accumulation of floating plastic (of 1-0.01 mm) in subtropical gyres. Particles of 1 μm in the gyres start sinking largely due to vertical advection, whereas in the equatorial Pacific they are more dependent on biofouling. The qualitative impacts of seasonality on sinking timescales are small, however, localized sooner sinking due to spring algal blooms is seen. This study maps processes that affect the sinking of virtual microplastic globally, which could ultimately impact the ocean plastic budget.
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Affiliation(s)
- Delphine Lobelle
- Institute for Marine and Atmospheric ResearchUtrecht UniversityUtrechtNetherlands
| | - Merel Kooi
- Aquatic Ecology and Water Quality Management GroupDepartment of Environmental SciencesWageningen UniversityWageningenNetherlands
| | - Albert A. Koelmans
- Aquatic Ecology and Water Quality Management GroupDepartment of Environmental SciencesWageningen UniversityWageningenNetherlands
| | - Charlotte Laufkötter
- Climate and Environmental PhysicsPhysics InstituteUniversity of BernBernSwitzerland
- Oeschger Centre for Climate Change ResearchUniversity of BernBernSwitzerland
| | - Cleo E. Jongedijk
- Department of Civil and Environmental EngineeringImperial College LondonLondonUK
| | - Christian Kehl
- Institute for Marine and Atmospheric ResearchUtrecht UniversityUtrechtNetherlands
| | - Erik van Sebille
- Institute for Marine and Atmospheric ResearchUtrecht UniversityUtrechtNetherlands
- Centre for Complex Systems StudiesUtrecht UniversityUtrechtNetherlands
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9
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Rusca M, Messori G, Di Baldassarre G. Scenarios of Human Responses to Unprecedented Social-Environmental Extreme Events. Earths Future 2021; 9:e2020EF001911. [PMID: 33869652 PMCID: PMC8047902 DOI: 10.1029/2020ef001911] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 01/25/2021] [Accepted: 02/16/2021] [Indexed: 06/01/2023]
Abstract
In a rapidly changing world, what is today an unprecedented extreme may soon become the norm. As a result, extreme-related disasters are expected to become more frequent and intense. This will have widespread socio-economic consequences and affect the ability of different societal groups to recover from and adapt to rapidly changing environmental conditions. Therefore, there is the need to decipher the relation between genesis of unprecedented events, accumulation and distribution of risk, and recovery trajectories across different societal groups. Here, we develop an analytical approach to unravel the complexity of future extremes and multiscalar societal responses-from households to national governments and from immediate impacts to longer term recovery. This requires creating new forms of knowledge that integrate analyses of the past-that is, structural causes and political processes of risk accumulation and differentiated recovery trajectories-with plausible scenarios of future environmental extremes grounded in the event-specific literature. We specifically seek to combine the physical characteristics of the extremes with examinations of how culture, politics, power, and policy visions shape societal responses to unprecedented events, and interpret the events as social-environmental extremes. This new approach, at the nexus between social and natural sciences, has the concrete advantage of providing an impact-focused vision of future social-environmental risks, beyond what is achievable within conventional disciplinary boundaries. In this paper, we focus on extreme flooding events and the societal responses they elicit. However, our approach is flexible and applicable to a wide range of extreme events. We see it as the first building block of a new field of research, allowing for novel and integrated theoretical explanations and forecasting of social-environmental extremes.
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Affiliation(s)
- Maria Rusca
- Department of Earth SciencesUppsala UniversityUppsalaSweden
- Centre of Natural Hazards and Disaster Science (CNDS)UppsalaSweden
| | - Gabriele Messori
- Department of Earth SciencesUppsala UniversityUppsalaSweden
- Centre of Natural Hazards and Disaster Science (CNDS)UppsalaSweden
- Department of MeteorologyStockholm UniversityStockholmSweden
- Bolin Centre for Climate ResearchStockholmSweden
| | - Giuliano Di Baldassarre
- Department of Earth SciencesUppsala UniversityUppsalaSweden
- Centre of Natural Hazards and Disaster Science (CNDS)UppsalaSweden
- Department of Integrated Water Systems and GovernanceIHE Delftthe Netherlands
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Cortés‐Ortuño D, Fabian K, de Groot LV. Single Particle Multipole Expansions From Micromagnetic Tomography. Geochem Geophys Geosyst 2021; 22:e2021GC009663. [PMID: 34220358 PMCID: PMC8243950 DOI: 10.1029/2021gc009663] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/19/2021] [Revised: 03/01/2021] [Accepted: 03/01/2021] [Indexed: 06/13/2023]
Abstract
Micromagnetic tomography aims at reconstructing large numbers of individual magnetizations of magnetic particles from combining high-resolution magnetic scanning techniques with micro X-ray computed tomography (microCT). Previous work demonstrated that dipole moments can be robustly inferred, and mathematical analysis showed that the potential field of each particle is uniquely determined. Here, we describe a mathematical procedure to recover higher orders of the magnetic potential of the individual magnetic particles in terms of their spherical harmonic expansions (SHE). We test this approach on data from scanning superconducting quantum interference device microscopy and microCT of a reference sample. For particles with high signal-to-noise ratio of the magnetic scan we demonstrate that SHE up to order n = 3 can be robustly recovered. This additional level of detail restricts the possible internal magnetization structures of the particles and provides valuable rock magnetic information with respect to their stability and reliability as paleomagnetic remanence carriers. Micromagnetic tomography therefore enables a new approach for detailed rock magnetic studies on large ensembles of individual particles.
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Affiliation(s)
- David Cortés‐Ortuño
- Paleomagnetic Laboratory Fort HoofddijkDepartment of Earth SciencesUtrecht UniversityUtrechtThe Netherlands
| | - Karl Fabian
- Norwegian University of Science and Technology (NTNU)TrondheimNorway
| | - Lennart V. de Groot
- Paleomagnetic Laboratory Fort HoofddijkDepartment of Earth SciencesUtrecht UniversityUtrechtThe Netherlands
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11
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Solomatova NV, Caracas R. Buoyancy and Structure of Volatile-Rich Silicate Melts. J Geophys Res Solid Earth 2021; 126:e2020JB021045. [PMID: 33680690 PMCID: PMC7900987 DOI: 10.1029/2020jb021045] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/26/2020] [Revised: 12/17/2020] [Accepted: 12/20/2020] [Indexed: 06/12/2023]
Abstract
The early Earth was marked by at least one global magma ocean. Melt buoyancy played a major role for its evolution. Here we model the composition of the magma ocean using a six-component pyrolite melt, to which we add volatiles in the form of carbon as molecular CO or CO2 and hydrogen as molecular H2O or through substitution for magnesium. We compute the density relations from first-principles molecular dynamics simulations. We find that the addition of volatiles renders all the melts more buoyant compared to the reference volatile-free pyrolite. The effect is pressure dependent, largest at the surface, decreasing to about 20 GPa, and remaining roughly constant to 135 GPa. The increased buoyancy would have enhanced convection and turbulence, and thus promoted the chemical exchanges of the magma ocean with the early atmosphere. We determine the partial molar volume of both H2O and CO2 throughout the magma ocean conditions. We find a pronounced dependence with temperature at low pressures, whereas at megabar pressures the partial molar volumes are independent of temperature. At all pressures, the polymerization of the silicate melt is strongly affected by the amount of oxygen added to the system while being only weakly affected by the specific type of volatile added.
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Affiliation(s)
- Natalia V. Solomatova
- CNRSEcole Normale Supérieure de LyonLaboratoire de Géologie de Lyon LGLTPE UMR5276Centre Blaise PascalLyonFrance
| | - Razvan Caracas
- CNRSEcole Normale Supérieure de LyonLaboratoire de Géologie de Lyon LGLTPE UMR5276Centre Blaise PascalLyonFrance
- The Center for Earth Evolution and Dynamics (CEED)University of OsloOsloNorway
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Lichtenberg T, Bower DJ, Hammond M, Boukrouche R, Sanan P, Tsai S, Pierrehumbert RT. Vertically Resolved Magma Ocean-Protoatmosphere Evolution: H 2, H 2O, CO 2, CH 4, CO, O 2, and N 2 as Primary Absorbers. J Geophys Res Planets 2021; 126:e2020JE006711. [PMID: 33777608 PMCID: PMC7988593 DOI: 10.1029/2020je006711] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Revised: 01/05/2021] [Accepted: 01/08/2021] [Indexed: 06/12/2023]
Abstract
The earliest atmospheres of rocky planets originate from extensive volatile release during magma ocean epochs that occur during assembly of the planet. These establish the initial distribution of the major volatile elements between different chemical reservoirs that subsequently evolve via geological cycles. Current theoretical techniques are limited in exploring the anticipated range of compositional and thermal scenarios of early planetary evolution, even though these are of prime importance to aid astronomical inferences on the environmental context and geological history of extrasolar planets. Here, we present a coupled numerical framework that links an evolutionary, vertically resolved model of the planetary silicate mantle with a radiative-convective model of the atmosphere. Using this method, we investigate the early evolution of idealized Earth-sized rocky planets with end-member, clear-sky atmospheres dominated by either H2, H2O, CO2, CH4, CO, O2, or N2. We find central metrics of early planetary evolution, such as energy gradient, sequence of mantle solidification, surface pressure, or vertical stratification of the atmosphere, to be intimately controlled by the dominant volatile and outgassing history of the planet. Thermal sequences fall into three general classes with increasing cooling timescale: CO, N2, and O2 with minimal effect, H2O, CO2, and CH4 with intermediate influence, and H2 with several orders of magnitude increase in solidification time and atmosphere vertical stratification. Our numerical experiments exemplify the capabilities of the presented modeling framework and link the interior and atmospheric evolution of rocky exoplanets with multiwavelength astronomical observations.
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Affiliation(s)
- Tim Lichtenberg
- Atmospheric, Oceanic and Planetary Physics, Department of PhysicsUniversity of OxfordOxfordUK
| | - Dan J. Bower
- Center for Space and HabitabilityUniversity of BernBernSwitzerland
| | - Mark Hammond
- Department of the Geophysical SciencesUniversity of ChicagoChicagoILUSA
| | - Ryan Boukrouche
- Atmospheric, Oceanic and Planetary Physics, Department of PhysicsUniversity of OxfordOxfordUK
| | - Patrick Sanan
- Institute of Geophysics, Department of Earth SciencesETH ZurichZurichSwitzerland
| | - Shang‐Min Tsai
- Atmospheric, Oceanic and Planetary Physics, Department of PhysicsUniversity of OxfordOxfordUK
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Ratnarajah L, Blain S, Boyd PW, Fourquez M, Obernosterer I, Tagliabue A. Resource Colimitation Drives Competition Between Phytoplankton and Bacteria in the Southern Ocean. Geophys Res Lett 2021; 48:e2020GL088369. [PMID: 33518833 PMCID: PMC7816276 DOI: 10.1029/2020gl088369] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2020] [Revised: 09/12/2020] [Accepted: 11/20/2020] [Indexed: 06/01/2023]
Abstract
Across the Southern Ocean, phytoplankton growth is governed by iron and light, while bacterial growth is regulated by iron and labile dissolved organic carbon (LDOC). We use a mechanistic model to examine how competition for iron between phytoplankton and bacteria responds to changes in iron, light, and LDOC. Consistent with experimental evidence, increasing iron and light encourages phytoplankton dominance, while increasing LDOC and decreasing light favors bacterial dominance. Under elevated LDOC, bacteria can outcompete phytoplankton for iron, most easily under lower iron. Simulations reveal that bacteria are major iron consumers and suggest that luxury storage plays a key role in competitive iron uptake. Under seasonal conditions typical of the Southern Ocean, sources of LDOC besides phytoplankton exudation modulate the strength of competitive interactions. Continued investigations on the competitive fitness of bacteria in driving changes in primary production in iron-limited systems will be invaluable in refining these results.
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Affiliation(s)
- Lavenia Ratnarajah
- Department of EarthOcean and Ecological SciencesSchool of Environmental SciencesUniversity of LiverpoolLiverpoolUK
| | - Stéphane Blain
- Sorbonne UniversitéCNRSLaboratoire d'Océanographie Microbienne (LOMIC)Observatoire Océanologique de BanyulsBanyuls sur merFrance
| | - Philip W. Boyd
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaHobartTASAustralia
| | - Marion Fourquez
- Institute for Marine and Antarctic StudiesUniversity of TasmaniaHobartTASAustralia
- Aix Marseille Univ.Universite de ToulonCNRSIRDMIO UM 110MarseilleFrance
| | - Ingrid Obernosterer
- Sorbonne UniversitéCNRSLaboratoire d'Océanographie Microbienne (LOMIC)Observatoire Océanologique de BanyulsBanyuls sur merFrance
| | - Alessandro Tagliabue
- Department of EarthOcean and Ecological SciencesSchool of Environmental SciencesUniversity of LiverpoolLiverpoolUK
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Bean JL, Raymond SN, Owen JE. The Nature and Origins of Sub-Neptune Size Planets. J Geophys Res Planets 2021; 126:e2020JE006639. [PMID: 33680689 PMCID: PMC7900964 DOI: 10.1029/2020je006639] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 10/02/2020] [Accepted: 10/21/2020] [Indexed: 06/12/2023]
Abstract
Planets intermediate in size between the Earth and Neptune, and orbiting closer to their host stars than Mercury does the Sun, are the most common type of planet revealed by exoplanet surveys over the last quarter century. Results from NASA's Kepler mission have revealed a bimodality in the radius distribution of these objects, with a relative underabundance of planets between 1.5 and 2.0R ⊕ . This bimodality suggests that sub-Neptunes are mostly rocky planets that were born with primary atmospheres a few percent by mass accreted from the protoplanetary nebula. Planets above the radius gap were able to retain their atmospheres ("gas-rich super-Earths"), while planets below the radius gap lost their atmospheres and are stripped cores ("true super-Earths"). The mechanism that drives atmospheric loss for these planets remains an outstanding question, with photoevaporation and core-powered mass loss being the prime candidates. As with the mass-loss mechanism, there are two contenders for the origins of the solids in sub-Neptune planets: the migration model involves the growth and migration of embryos from beyond the ice line, while the drift model involves inward-drifting pebbles that coagulate to form planets close-in. Atmospheric studies have the potential to break degeneracies in interior structure models and place additional constraints on the origins of these planets. However, most atmospheric characterization efforts have been confounded by aerosols. Observations with upcoming facilities are expected to finally reveal the atmospheric compositions of these worlds, which are arguably the first fundamentally new type of planetary object identified from the study of exoplanets.
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Affiliation(s)
- Jacob L. Bean
- Department of Astronomy & AstrophysicsUniversity of ChicagoChicagoILUSA
| | - Sean N. Raymond
- Laboratoire d'Astrophysique de BordeauxCNRS and Université de BordeauxPessacFrance
| | - James E. Owen
- Department of PhysicsAstrophysics GroupImperial College LondonLondonUK
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