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Nightside condensation of iron in an ultrahot giant exoplanet 期刊论文
NATURE, 2020, 580 (7805) : 597-+
作者:  Lu, Zhihao;  Zou, Jianling;  Li, Shuang;  Topper, Michael J.;  Tao, Yong;  Zhang, Hao;  Jiao, Xi;  Xie, Wenbing;  Kong, Xiangqian;  Vaz, Michelle;  Li, Huili;  Cai, Yi;  Xia, Limin;  Huang, Peng;  Rodgers, Kristen;  Lee, Beverly;  Riemer, Joanne B.;  Day, Chi-Ping;  Yen, Ray-Whay Chiu;  Cui, Ying;  Wang, Yujiao;  Wang, Yanni;  Zhang, Weiqiang;  Easwaran, Hariharan;  Hulbert, Alicia;  Kim, KiBem;  Juergens, Rosalyn A.;  Yang, Stephen C.;  Battafarano, Richard J.;  Bush, Errol L.;  Broderick, Stephen R.;  Cattaneo, Stephen M.;  Brahmer, Julie R.;  Rudin, Charles M.;  Wrangle, John;  Mei, Yuping;  Kim, Young J.;  Zhang, Bin;  Wang, Ken Kang-Hsin;  Forde, Patrick M.;  Margolick, Joseph B.;  Nelkin, Barry D.;  Zahnow, Cynthia A.;  Pardoll, Drew M.;  Housseau, Franck;  Baylin, Stephen B.;  Shen, Lin;  Brock, Malcolm V.
收藏  |  浏览/下载：63/0  |  提交时间：2020/07/03

Ultrahot giant exoplanets receive thousands of times Earth'  s insolation(1,2). Their high-temperature atmospheres (greater than 2,000 kelvin) are ideal laboratories for studying extreme planetary climates and chemistry(3-5). Daysides are predicted to be cloud-free, dominated by atomic species(6) and much hotter than nightsides(5,7,8). Atoms are expected to recombine into molecules over the nightside(9), resulting in different day and night chemistries. Although metallic elements and a large temperature contrast have been observed(10-14), no chemical gradient has been measured across the surface of such an exoplanet. Different atmospheric chemistry between the day-to-night ('  evening'  ) and night-to-day ('  morning'  ) terminators could, however, be revealed as an asymmetric absorption signature during transit(4,7,15). Here we report the detection of an asymmetric atmospheric signature in the ultrahot exoplanet WASP-76b. We spectrally and temporally resolve this signature using a combination of high-dispersion spectroscopy with a large photon-collecting area. The absorption signal, attributed to neutral iron, is blueshifted by -11 +/- 0.7 kilometres per second on the trailing limb, which can be explained by a combination of planetary rotation and wind blowing from the hot dayside(16). In contrast, no signal arises from the nightside close to the morning terminator, showing that atomic iron is not absorbing starlight there. We conclude that iron must therefore condense during its journey across the nightside.


Absorption lines of iron in the dayside atmosphere of an ultrahot giant exoplanet disappear after travelling across the nightside, showing that the iron has condensed during its travel.


  
Mass balance of the Greenland Ice Sheet from 1992 to 2018 期刊论文
NATURE, 2020, 579 (7798) : 233-+
作者:  Scudellari, Megan
收藏  |  浏览/下载：11/0  |  提交时间：2020/04/16

The Greenland Ice Sheet has been a major contributor to global sea-level rise in recent decades(1,2), and it is expected to continue to be so(3). Although increases in glacier flow(4-6) and surface melting(7-9) have been driven by oceanic(10-12) and atmospheric(13,14) warming, the magnitude and trajectory of the ice sheet'  s mass imbalance remain uncertain. Here we compare and combine 26 individual satellite measurements of changes in the ice sheet'  s volume, flow and gravitational potential to produce a reconciled estimate of its mass balance. The ice sheet was close to a state of balance in the 1990s, but annual losses have risen since then, peaking at 345 +/- 66 billion tonnes per year in 2011. In all, Greenland lost 3,902 +/- 342 billion tonnes of ice between 1992 and 2018, causing the mean sea level to rise by 10.8 +/- 0.9 millimetres. Using three regional climate models, we show that the reduced surface mass balance has driven 1,964 +/- 565 billion tonnes (50.3 per cent) of the ice loss owing to increased meltwater runoff. The remaining 1,938 +/- 541 billion tonnes (49.7 per cent) of ice loss was due to increased glacier dynamical imbalance, which rose from 46 +/- 37 billion tonnes per year in the 1990s to 87 +/- 25 billion tonnes per year since then. The total rate of ice loss slowed to 222 +/- 30 billion tonnes per year between 2013 and 2017, on average, as atmospheric circulation favoured cooler conditions(15) and ocean temperatures fell at the terminus of Jakobshavn Isbr AE(16). Cumulative ice losses from Greenland as a whole have been close to the rates predicted by the Intergovernmental Panel on Climate Change for their high-end climate warming scenario(17), which forecast an additional 70 to 130 millimetres of global sea-level rise by 2100 compared with their central estimate.


  
Projecting marine species range shifts from only temperature can mask climate vulnerability 期刊论文
GLOBAL CHANGE BIOLOGY, 2019
作者:  McHenry, Jennifer;  Welch, Heather;  Lester, Sarah E.;  Saba, Vincent
收藏  |  浏览/下载：9/0  |  提交时间：2019/11/27
climate change  habitat suitability models  marine species  range shifts  species vulnerability  
To improve weather and climate models, researchers are chasing atmospheric gravity waves 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2019, 116 (39) : 19218-19221
作者:  Mann, Adam
收藏  |  浏览/下载：3/0  |  提交时间：2019/11/27
ENSO and NAO affect long-term leaf litter dynamics and stoichiometry of Scots pine and European beech mixedwoods 期刊论文
GLOBAL CHANGE BIOLOGY, 2019, 25 (9) : 3070-3090
作者:  Gonzalez de Andres, Ester;  Blanco, Juan A.;  Bosco Imbert, J.;  Guan, Biing T.;  Lo, Yueh-Hsin;  Castillo, Federico J.
收藏  |  浏览/下载：17/0  |  提交时间：2019/11/27
ensemble empirical mode decomposition (EEMD)  Fagus sylvatica  leaf litter  nutrient cycling  nutrient limitation  Pinus sylvestris  Pyrenees  stoichiometry  structural equation model (SEM)  
Direct observations of submarine melt and subsurface geometry at a tidewater glacier 期刊论文
SCIENCE, 2019, 365 (6451) : 369-+
作者:  Sutherland, D. A.;  Jackson, R. H.;  Kienholz, C.;  Amundson, J. M.;  Dryer, W. P.;  Duncan, D.;  Eidam, E. F.;  Motyka, R. J.;  Nash, J. D.
收藏  |  浏览/下载：10/0  |  提交时间：2019/11/27
The great Atlantic Sargassum belt 期刊论文
SCIENCE, 2019, 365 (6448) : 83-+
作者:  Wang, Mengqiu;  Hu, Chuanmin;  Barnes, Brian B.;  Mitchum, Gary;  Lapointe, Brian;  Montoya, Joseph P.
收藏  |  浏览/下载：6/0  |  提交时间：2019/11/27
Phytoplankton decline in the eastern North Pacific transition zone associated with atmospheric blocking 期刊论文
GLOBAL CHANGE BIOLOGY, 2019, 25 (10) : 3485-3493
作者:  Le, Chengfeng;  Wu, Shuyu;  Hu, Chuanmin;  Beck, Marcus W.;  Yang, Xuchao
收藏  |  浏览/下载：9/0  |  提交时间：2019/11/26
atmospheric blocking  Ekman transport  global change  jet stream  North Pacific transition zone  phytoplankton  
Restoration of brain circulation and cellular functions hours post-mortem 期刊论文
NATURE, 2019, 568 (7752) : 336-+
作者:  Vrselja, Zvonimir;  Daniele, Stefano G.;  Silbereis, John;  Talpo, Francesca;  Morozov, Yury M.;  Sousa, Andre M. M.;  Tanaka, Brian S.;  Skarica, Mario;  Pletikos, Mihovil;  Kaur, Navjot;  Zhuang, Zhen W.;  Liu, Zhao;  Alkawadri, Rafeed;  Sinusas, Albert J.;  Latham, Stephen R.;  Waxman, Stephen G.;  Sestan, Nenad
收藏  |  浏览/下载：8/0  |  提交时间：2019/11/27
Geographical adaptation prevails over species-specific determinism in trees' vulnerability to climate change at Mediterranean rear-edge forests 期刊论文
GLOBAL CHANGE BIOLOGY, 2019, 25 (4) : 1296-1314
作者:  Dorado-Linan, Isabel;  Piovesan, Gianluca;  Martinez-Sancho, Elisabet;  Gea-Izquierdo, Guillermo;  Zang, Christian;  Canellas, Isabel;  Castagneri, Daniele;  Di Filippo, Alfredo;  Gutierrez, Emilia;  Ewald, Joerg;  Fernandez-de-Una, Laura;  Hornstein, Daniel;  Jantsch, Matthias C.;  Levanic, Tom;  Mellert, Karl H.;  Vacchiano, Giorgio;  Zlatanov, Tzvetan;  Menzel, Annette
收藏  |  浏览/下载：14/0  |  提交时间：2019/04/09
climate change  drought  Mediterranean Basin  rear-edge forests  tolerance indices  tree growth