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Ice retreat in Wilkes Basin of East Antarctica during a warm interglacial 期刊论文
NATURE, 2020, 583 (7817) : 554-+
作者:  T. Blackburn;  G. H. Edwards;  S. Tulaczyk;  M. Scudder;  G. Piccione;  B. Hallet;  N. McLean;  J. C. Zachos;  B. Cheney;  J. T. Babbe
收藏  |  浏览/下载:21/0  |  提交时间:2020/08/09

Uranium isotopes in subglacial precipitates from the Wilkes Basin of the East Antarctic Ice Sheet reveal ice retreat during a warm Pleistocene interglacial period about 400,000 years ago.


Efforts to improve sea level forecasting on a warming planet have focused on determining the temperature, sea level and extent of polar ice sheets during Earth'  s past interglacial warm periods(1-3). About 400,000 years ago, during the interglacial period known as Marine Isotopic Stage 11 (MIS11), the global temperature was 1 to 2 degrees Celsius greater(2)and sea level was 6 to 13 metres higher(1,3). Sea level estimates in excess of about 10 metres, however, have been discounted because these require a contribution from the East Antarctic Ice Sheet(3), which has been argued to have remained stable for millions of years before and includes MIS11(4,5). Here we show how the evolution of(234)U enrichment within the subglacial waters of East Antarctica recorded the ice sheet'  s response to MIS11 warming. Within the Wilkes Basin, subglacial chemical precipitates of opal and calcite record accumulation of(234)U (the product of rock-water contact within an isolated subglacial reservoir) up to 20 times higher than that found in marine waters. The timescales of(234)U enrichment place the inception of this reservoir at MIS11. Informed by the(234)U cycling observed in the Laurentide Ice Sheet, where(234)U accumulated during periods of ice stability(6)and was flushed to global oceans in response to deglaciation(7), we interpret our East Antarctic dataset to represent ice loss within the Wilkes Basin at MIS11. The(234)U accumulation within the Wilkes Basin is also observed in the McMurdo Dry Valleys brines(8-10), indicating(11)that the brine originated beneath the adjacent East Antarctic Ice Sheet. The marine origin of brine salts(10)and bacteria(12)implies that MIS11 ice loss was coupled with marine flooding. Collectively, these data indicate that during one of the warmest Pleistocene interglacials, the ice sheet margin at the Wilkes Basin retreated to near the precipitate location, about 700 kilometres inland from the current position of the ice margin, which-assuming current ice volumes-would have contributed about 3 to 4 metres(13)to global sea levels.


  
Potential for large-scale CO2 removal via enhanced rock weathering with croplands 期刊论文
NATURE, 2020, 583 (7815) : 242-+
作者:  David J. Beerling;  Euripides P. Kantzas;  Mark R. Lomas;  Peter Wade;  Rafael M. Eufrasio;  Phil Renforth;  Binoy Sarkar;  M. Grace Andrews;  Rachael H. James;  Christopher R. Pearce;  Jean-Francois Mercure;  Hector Pollitt;  Philip B. Holden;  Neil R. Edwards;  Madhu Khanna;  Lenny Koh;  Shaun Quegan;  Nick F. Pidgeon;  Ivan A. Janssens;  James Hansen;  Steven A. Banwart
收藏  |  浏览/下载:18/0  |  提交时间:2020/07/14

Enhanced silicate rock weathering (ERW), deployable with croplands, has potential use for atmospheric carbon dioxide (CO2) removal (CDR), which is now necessary to mitigate anthropogenic climate change(1). ERW also has possible co-benefits for improved food and soil security, and reduced ocean acidification(2-4). Here we use an integrated performance modelling approach to make an initial techno-economic assessment for 2050, quantifying how CDR potential and costs vary among nations in relation to business-as-usual energy policies and policies consistent with limiting future warming to 2 degrees Celsius(5). China, India, the USA and Brazil have great potential to help achieve average global CDR goals of 0.5 to 2gigatonnes of carbon dioxide (CO2) per year with extraction costs of approximately US$80-180 per tonne of CO2. These goals and costs are robust, regardless of future energy policies. Deployment within existing croplands offers opportunities to align agriculture and climate policy. However, success will depend upon overcoming political and social inertia to develop regulatory and incentive frameworks. We discuss the challenges and opportunities of ERW deployment, including the potential for excess industrial silicate materials (basalt mine overburden, concrete, and iron and steel slag) to obviate the need for new mining, as well as uncertainties in soil weathering rates and land-ocean transfer of weathered products.


  
A remnant planetary core in the hot-Neptune desert 期刊论文
NATURE, 2020, 583 (7814) : 39-+
作者:  David J. Armstrong;  Thé;  o A. Lopez;  Vardan Adibekyan;  Richard A. Booth;  Edward M. Bryant;  Karen A. Collins;  Magali Deleuil;  Alexandre Emsenhuber;  Chelsea X. Huang;  George W. King;  Jorge Lillo-Box;  Jack J. Lissauer;  Elisabeth Matthews;  Olivier Mousis;  Louise D. Nielsen;  Hugh Osborn;  Jon Otegi;  Nuno C. Santos;  ;  rgio G. Sousa;  Keivan G. Stassun;  Dimitri Veras;  Carl Ziegler;  Jack S. Acton;  Jose M. Almenara;  David R. Anderson;  David Barrado;  Susana C. C. Barros;  Daniel Bayliss;  Claudia Belardi;  Francois Bouchy;  ;  sar Briceñ;  o;  Matteo Brogi;  David J. A. Brown;  Matthew R. Burleigh;  Sarah L. Casewell;  Alexander Chaushev;  David R. Ciardi;  Kevin I. Collins;  Knicole D. Coló;  n;  Benjamin F. Cooke;  Ian J. M. Crossfield;  Rodrigo F. Dí;  az;  Elisa Delgado Mena;  Olivier D. S. Demangeon;  Caroline Dorn;  Xavier Dumusque;  Philipp Eigmü;  ller;  Michael Fausnaugh;  Pedro Figueira;  Tianjun Gan;  Siddharth Gandhi;  Samuel Gill;  Erica J. Gonzales;  Michael R. Goad;  Maximilian N. Gü;  nther;  Ravit Helled;  Saeed Hojjatpanah;  Steve B. Howell;  James Jackman;  James S. Jenkins;  Jon M. Jenkins;  Eric L. N. Jensen;  Grant M. Kennedy;  David W. Latham;  Nicholas Law;  Monika Lendl;  Michael Lozovsky;  Andrew W. Mann;  Maximiliano Moyano;  James McCormac;  Farzana Meru;  Christoph Mordasini;  Ares Osborn;  Don Pollacco;  Didier Queloz;  Liam Raynard;  George R. Ricker;  Pamela Rowden;  Alexandre Santerne;  Joshua E. Schlieder;  Sara Seager;  Lizhou Sha;  Thiam-Guan Tan;  Rosanna H. Tilbrook;  Eric Ting;  Sté;  phane Udry;  Roland Vanderspek;  Christopher A. Watson;  Richard G. West;  Paul A. Wilson;  Joshua N. Winn;  Peter Wheatley;  Jesus Noel Villasenor;  Jose I. Vines;  Zhuchang Zhan
收藏  |  浏览/下载:20/0  |  提交时间:2020/07/06

The interiors of giant planets remain poorly understood. Even for the planets in the Solar System, difficulties in observation lead to large uncertainties in the properties of planetary cores. Exoplanets that have undergone rare evolutionary processes provide a route to understanding planetary interiors. Planets found in and near the typically barren hot-Neptune '  desert'  (1,2)(a region in mass-radius space that contains few planets) have proved to be particularly valuable in this regard. These planets include HD149026b(3), which is thought to have an unusually massive core, and recent discoveries such as LTT9779b(4)and NGTS-4b(5), on which photoevaporation has removed a substantial part of their outer atmospheres. Here we report observations of the planet TOI-849b, which has a radius smaller than Neptune'  s but an anomalously large mass of39.1-2.6+2.7Earth masses and a density of5.2-0.8+0.7grams per cubic centimetre, similar to Earth'  s. Interior-structure models suggest that any gaseous envelope of pure hydrogen and helium consists of no more than3.9-0.9+0.8 per cent of the total planetary mass. The planet could have been a gas giant before undergoing extreme mass loss via thermal self-disruption or giant planet collisions, or it could have avoided substantial gas accretion, perhaps through gap opening or late formation(6). Although photoevaporation rates cannot account for the mass loss required to reduce a Jupiter-like gas giant, they can remove a small (a few Earth masses) hydrogen and helium envelope on timescales of several billion years, implying that any remaining atmosphere on TOI-849b is likely to be enriched by water or other volatiles from the planetary interior. We conclude that TOI-849b is the remnant core of a giant planet.


Observations of TOI-849b reveal a radius smaller than Neptune'  s but a large mass of about 40 Earth masses, indicating that the planet is the remnant core of a gas giant.


  
Not all driver mutations are equal 期刊论文
NATURE, 2020, 580 (7805) : 595-596
作者:  Legendre, Lucas J.;  Rubilar-Rogers, David;  Musser, Grace M.;  Davis, Sarah N.;  Otero, Rodrigo A.;  Vargas, Alexander O.;  Clarke, Julia A.
收藏  |  浏览/下载:12/0  |  提交时间:2020/07/03

A study of cancer-associated mutations in normal endometrial glands of the uterus has now been performed using whole-genome sequencing. The analysis sheds light on the early changes that lead to invasive disease.


  
SCIENCE FUNDING FACES POST-PANDEMIC UPHEAVALS 期刊论文
NATURE, 2020, 582 (7811) : 164-165
作者:  Mueller, Johannes B.;  Geyer, Philipp E.;  Colaco, Ana R.;  Treit, Peter, V;  Strauss, Maximilian T.;  Oroshi, Mario;  Doll, Sophia;  Winter, Sebastian Virreira;  Bader, Jakob M.;  Koehler, Niklas;  Theis, Fabian;  Santos, Alberto;  Mann, Matthias
收藏  |  浏览/下载:17/0  |  提交时间:2020/07/03
Australian junior scientists report damaging lack of support at work 期刊论文
NATURE, 2020, 579 (7799) : 457-458
作者:  Aveline, David C.;  Williams, Jason R.;  Elliott, Ethan R.;  Dutenhoffer, Chelsea;  Kellogg, James R.;  Kohel, James M.;  Lay, Norman E.;  Oudrhiri, Kamal;  Shotwell, Robert F.;  Yu, Nan;  Thompson, Robert J.
收藏  |  浏览/下载:7/0  |  提交时间:2020/07/03
HOW DOES COVID-19 KILL? UNCERTAINTY HAMPERS DOCTORS' ABILITY TO CHOOSE TREATMENTS 期刊论文
NATURE, 2020, 580 (7803) : 311-312
作者:  Griffiths, Cameron D.;  Bilawchuk, Leanne M.;  McDonough, John E.;  Jamieson, Kyla C.;  Elawar, Farah;  Cen, Yuchen;  Duan, Wenming;  Lin, Cindy;  Song, Haeun;  Casanova, Jean-Laurent;  Ogg, Steven;  Jensen, Lionel Dylan;  Thienpont, Bernard;  Kumar, Anil
收藏  |  浏览/下载:12/0  |  提交时间:2020/07/03
WHY POLLUTION IS FALLING IN SOME CITIES - BUT NOT OTHERS 期刊论文
NATURE, 2020, 580 (7803) : 313-313
作者:  Sulkowski, Parker L.;  Oeck, Sebastian;  Dow, Jonathan;  Economos, Nicholas G.;  Mirfakhraie, Lily;  Liu, Yanfeng;  Noronha, Katelyn;  Bao, Xun;  Li, Jing;  Shuch, Brian M.;  King, Megan C.;  Bindra, Ranjit S.;  Glazer, Peter M.
收藏  |  浏览/下载:15/0  |  提交时间:2020/07/03
HACKS TO HELP RESEARCHERS PUT WORDS ON THE PAGE 期刊论文
NATURE, 2020, 580 (7801) : 151-153
作者:  Lee, Jiyoon;  Rabbani, Cyrus C.;  Gao, Hongyu;  Steinhart, Matthew R.;  Woodruff, Benjamin M.;  Pflum, Zachary E.;  Kim, Alexander;  Heller, Stefan;  Liu, Yunlong;  Shipchandler, Taha Z.;  Koehler, Karl R.
收藏  |  浏览/下载:12/0  |  提交时间:2020/07/03

Productivity coaches, boot camps and online meet-ups teach researchers to avoid distractions and negative thoughts to get their writing projects done.


Productivity coaches, boot camps and online meet-ups teach researchers to avoid distractions and negative thoughts to get their writing projects done.


  
A Galactic-scale gas wave in the solar neighbourhood 期刊论文
NATURE, 2020, 578 (7794) : 237-+
作者:  Alves, Joao;  Zucker, Catherine;  Goodman, Alyssa A.;  Speagle, Joshua S.;  Meingast, Stefan;  Robitaille, Thomas;  Finkbeiner, Douglas P.;  Schlafly, Edward F.;  Green, Gregory M.
收藏  |  浏览/下载:14/0  |  提交时间:2020/07/03

The three-dimensional structure of all cloud complexes in the solar neighbourhood is revealed, showing a narrow and coherent 2.7-kpc arrangement of dense gas, in disagreement with the Gould Belt model.


For the past 150 years, the prevailing view of the local interstellar medium has been based on a peculiarity known as the Gould Belt(1-4), an expanding ring of young stars, gas and dust, tilted about 20 degrees to the Galactic plane. However, the physical relationship between local gas clouds has remained unknown because the accuracy in distance measurements to such clouds is of the same order as, or larger than, their sizes(5-7). With the advent of large photometric surveys(8) and the astrometric survey(9), this situation has changed(10). Here we reveal the three-dimensional structure of all local cloud complexes. We find a narrow and coherent 2.7-kiloparsec arrangement of dense gas in the solar neighbourhood that contains many of the clouds thought to be associated with the Gould Belt. This finding is inconsistent with the notion that these clouds are part of a ring, bringing the Gould Belt model into question. The structure comprises the majority of nearby star-forming regions, has an aspect ratio of about 1:20 and contains about three million solar masses of gas. Remarkably, this structure appears to be undulating, and its three-dimensional shape is well described by a damped sinusoidal wave on the plane of the Milky Way with an average period of about 2 kiloparsecs and a maximum amplitude of about 160 parsecs.