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Influence of upstream solar wind on magnetic field distribution in the Martian nightside ionosphere

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earth and Planetary Physics 2024年第5期8卷 728-741页

作者： JiaWei Gao ZhaoJin Rong Qi Zhang Anna Mittelholz Chi Zhang Yong Wei Key Laboratory of earth and Planetary Physics Institute of Geology and Geophysics Chinese Academy of Sciences College of earth and Planetary sciences University of Chinese Academy of Sciences Swedish Institute of space Physics department of earth sciences Center for space Physics and department of Astronomy Boston University

Using over eight years of Mars Atmosphere and Volatile Evolutio N （MAVEN） data,from November 2014 to May 2023,we have investigated the Martian nightside ionospheric magnetic field distribution under the influence of upstream solar wind drivers,including the interplanetary magnetic field intensity (∣BIMF∣),solar wind dynamic pressure （PSW）,solar extreme ultraviolet flux （EUV）,and Martian seasons （Ls）.Our analysis reveals pronounced correlations between magnetic field residuals and both∣BIMF∣and *** observed with EUV flux and Lswere weaker—notably,magnetic field residuals increased during periods of high EUV flux and at Mars *** find that the IMF penetrates to an altitude of 200 km under a wide range of upstream conditions,penetrating notably deeper under high∣BIMF∣*** analysis also indicates that EUV flux and IMF cone angle have minimal impact on IMF penetration *** findings provide useful constraints on the dynamic nature of Martian atmospheric escape processes and their evolution,suggesting that historical solar wind conditions may have facilitated deeper IMF penetration and higher rates of ionospheric escape than are observed ***,by establishing criteria for magnetic‘quiet’conditions,this study offers new insights into the planet’s magnetic environment under varying solar wind influences,knowledge that should help refine models of the Martian crustal magnetic field.

关键词： Martian magnetic field external magnetic field upstream solar wind drivers IMF penetration altitude magnetic field activity indices

Is Deep Time Geology Scientific?

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Journal of earth Science 2024年第2期35卷 700-703页

作者： T.Mark Harrison department of earth Planetary and Space SciencesUniversity of CaliforniaLos Angeles90095USA

We all know what car mechanics *** maintain and repair our automobiles according to established engineering *** all know what physicians *** maintain and repair our bodies according to established medical *** what is it that I do as a scientist?Indeed,am I a scientist?The answer to these questions depends on what we meant by“science”.

关键词： maintain Deep repair

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Global weirding at mass extinction horizons

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National Science Review 2024年第1期11卷 10-12页

作者： Gregory J.Retallack department of earth sciences University of Oregon

A strong motivation for studying mass extinctions is understanding how current climatic and biodiversity crises will affect creatures living on land such as ourselves. Perhaps the question is: how bad can it get? In that case, terrestrial Permian-Triassic mass extinctions are an irresistible worst-case scenario [1].

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Bayesian partial pooling to reduce uncertainty in overcoring rock stress estimation

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Journal of Rock Mechanics and Geotechnical Engineering 2024年第4期16卷 1192-1201页

作者： Yu Feng Ke Gao Suzanne Lacasse Norwegian Geotechnical Institute OsloNorway department of earth and space sciences Southern University of Science and TechnologyShenzhenChina

The state of in situ stress is a crucial parameter in subsurface engineering,especially for critical projects like nuclear waste *** one of the two ISRM suggested methods,the overcoring(OC)method is widely used to estimate the full stress tensors in rocks by independent regression analysis of the data from each OC ***,such customary independent analysis of individual OC tests,known as no pooling,is liable to yield unreliable test-specific stress estimates due to various uncertainty sources involved in the OC *** address this problem,a practical and no-cost solution is considered by incorporating into OC data analysis additional information implied within adjacent OC tests,which are usually available in OC measurement ***,this paper presents a Bayesian partial pooling(hierarchical)model for combined analysis of adjacent OC *** performed five case studies using OC test data made at a nuclear waste repository research site of *** results demonstrate that partial pooling of adjacent OC tests indeed allows borrowing of information across adjacent tests,and yields improved stress tensor estimates with reduced uncertainties simultaneously for all individual tests than they are independently analysed as no pooling,particularly for those unreliable no pooling stress estimates.A further model comparison shows that the partial pooling model also gives better predictive performance,and thus confirms that the information borrowed across adjacent OC tests is relevant and effective.

关键词： Overcoring stress measurement Uncertainty reduction Partial pooling Bayesian hierarchical model Nuclear waste repository

Soil security and global food security

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Frontiers of Agricultural Science and Engineering 2024年第2期11卷 297-302页

作者： David R.MONTGOMERY department of earth and space sciences University of Washington townSeattleWA 98105USA

Over the course of the postglacial period has managed to add degrade a substantial portion of the world's potential agricultural land. The soil loss and degradation that has repeatedly impacted regional societies around the world resulted from agricultural practices that increased the physical loss of soil(erosion), reduced soil organic matter, changed p H(acidification) or salinity,and disrupted or altered communities of soil life. In the coming century, as continued soil degradation threatens global food security while the global population keeps rising it is imperative that farmers develop and adopt soilhealth building(regenerative) practices to solve a problem that has plagued societies throughout history. Growing evidence suggests that agricultural systems that combine cover crops, reduced tillage, and diverse crop rotations can reduce erosion, enhance soil health and rebuild soil organic matter to cultivate beneficial soil life and harvest both economic and environmental benefits. In the coming post-oil world, global food security would benefit from a global effort to promote soil restoration to help addresses the challenge of sustainably feeding the world, increase soil-based carbon sequestration,protect on-farm biodiversity and reduce off-farm water pollution. Because soil security sets a solid foundation for global food security, agricultural policies and subsidies should be reformed to encourage farmers to adopt regenerative,soil-building practices.

关键词： Agriculture soil security food security regenerative

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Analysis of ancient mass extinction recoveries in marine environments: generating strategies for managing outcomes of the current mass extinction

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National Science Review 2024年第1期11卷 8-10页

作者： David J.Bottjer department of earth sciences University of Southern California

The defining feature of a mass extinction and its associated recovery is the global amount of extinction that occurred[1]. However, there is finer-scale detail to the story, as seen in the ongoing modern mass extinction(the sixth mass extinction), which exhibits variable effects among marine ecosystems and environments, and hence geographic areas [1].

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Late Ordovician Mass Extinction: earth, fire and ice

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National Science Review 2024年第1期11卷 51-65页

作者： David A.T.Harper Palaeoecosystems Group Department of Earth SciencesDurham University

The Late Ordovician Mass Extinction was the earliest of the ‘big’ five extinction events and the earliest to affect the trajectory of metazoan life. Two phases have been identified near the start of the Hirnantian period and in the middle. It was a massive taxonomic extinction, a weak phylogenetic extinction and a relatively benign ecological extinction. A rapid cooling, triggering a major ice age that reduced the temperature of surface waters, prompted a drop in sea level of some 100 m and introduced toxic bottom waters onto the shelves. These symptoms of more fundamental planetary processes have been associated with a range of factors with an underlying driver identified as volcanicity. Volcanic eruptions, and other products, may have extended back in time to at least the Sandbian and early Katian, suggesting the extinctions were more protracted and influential than hitherto documented.

关键词： Ordovician LOME paleoecology palaeobiogeography biotas

Recent advances in the magnetic reconnection, dipolarization, and auroral processes at giant planets from the perspective of comparative planetology

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earth and Planetary Physics 2024年第5期8卷 659-672页

作者： ZhongHua Yao RuiLong Guo Yong Wei Bertrand Bonfond Denis Grodent BinZheng Zhang William R.Dunn ZuYin Pu Key Laboratory of earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of Sciences College of earth and Planetary sciences University of Chinese Academy of Sciences Laboratoire de Physique Atmosphérique et Planétaire STAR InstituteUniversitéde Liège Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment Institute of Space SciencesShandong University department of earth sciences the University of Hong Kong department of Physics and Astronomy University College London School of earth and space sciences Peking University

Magnetic reconnection and dipolarization are crucial processes driving magnetospheric dynamics, including particle energization, mass circulation, and auroral processes, among others. Recent studies have revealed that these processes at Saturn and Jupiter are fundamentally different from the ones at earth. The reconnection and dipolarization processes are far more important than previously expected in the dayside magnetodisc of Saturn and potentially Jupiter. Dayside magnetodisc reconnection was directly identified by using Cassini measurements(Guo RL et al., 2018b) and was found to be drizzle-like and rotating in the magnetosphere of Saturn(Delamere et al., 2015b; Yao ZH et al., 2017a; Guo RL et al., 2019). Moreover, magnetic dipolarization could also exist at Saturn's dayside(Yao ZH et al., 2018), which is fundamentally different from the terrestrial situation. These new results significantly improve our understanding of giant planetary magnetospheric dynamics and provide key insights revealing the physics of planetary aurorae. Here, we briefly review these recent advances and their potential implications for future investigations.

关键词： magnetosphere magnetic reconnection magnetic depolarization

Characterizing extreme drought and wetness in Guangdong,China using global navigation satellite system and precipitation data

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Satellite Navigation 2024年第1期5卷 258-274页

作者： Hai Zhu Kejie Chen Haishan Chai Yuanbin Ye Wenjian Liu department of earth and space sciences Southern University of Science and TechnologyShenzhen518055China Lands and Resource department of Guangdong Province Surveying and Mapping InstituteGuangzhou510500China

As global temperature rises,the frequency of extreme climate events,e.g.,severe droughts and floods,has increased significantly and caused severe damage over the past *** this regard,precipitation efficiency,a crucial meteorological parameter,could provide valuable insights for a better understanding of the patterns and characteristics of these extreme *** this study,taking Guangdong province as an exemplary region,we first obtained long-term and high-resolution historical records of precipitation efficiency by integrating the observations from a dense network of Global Navigation Satellite System(GNSS)stations with precipitation data,and then characterized the extreme drought and wetness through climate *** found a distinct seasonal trend in precipitation efficiency in Guangdong,with annual fluctuations ranging from 10 to 25%.Notably,precipitation efficiency is higher in proximity to the Pearl River Delta Plain and gradually decreases towards the east and *** occurrence of anomalous peaks and valleys in precipitation efficiency generally corresponds to dry and wet conditions,respectively.A total of 9 extreme wet events and 6 dry events occurred from January 2007 to May 2022,with durations from 3 to 6 *** results also demonstrated that both wet and dry frequencies exhibit an increasing trend with the expansion of the time scale,and the frequency of extreme events near the Pearl River Delta Plain surpasses that of other ***,the propagation time from meteorological anomalies to agricultural and hydrological anomalies is about 3 *** periodic characteristics of meteorological anomalies are identified as the primary driver for other anomalous periodic *** work unveils the long-term dynamic behavior of precipitation efficiency,as well as the characteristics of extreme drought and wetness events in the regions characterized by intricate land–atmosphere interactions.

关键词： GNSS Precipitation efficiency Extreme drought and wetness