Earth and Planetary Physics最新文献

{"title":"The Mars rover subsurface penetrating radar onboard China's Mars 2020 mission","authors":"Bin Zhou,&nbsp;ShaoXiang Shen,&nbsp;Wei Lu,&nbsp;Qing Liu,&nbsp;ChuanJun Tang,&nbsp;ShiDong Li,&nbsp;GuangYou Fang","doi":"10.26464/epp2020054","DOIUrl":"10.26464/epp2020054","url":null,"abstract":"<p>China's Mars probe, named Tianwen-1, including an orbiter and a landing rover, will be launched during the July-August 2020 Mars launch windows. Selected to be among the rover payloads is a Subsurface Penetrating Radar module (RoSPR). The main scientific objective of the RoSPR is to characterize the thickness and sub-layer distribution of the Martian soil. The RoSPR consists of two channels. The low frequency channel of the RoSPR will penetrate the Martian soil to depths of 10 to 100 m with a resolution of a few meters. The higher frequency channel will penetrate to a depth of 3 to 10 m with a resolution of a few centimeters. This paper describes the design of the instrument and some results of field experiments.</p>","PeriodicalId":45246,"journal":{"name":"Earth and Planetary Physics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2020-08-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.26464/epp2020054","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"107258671","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characteristics of the quasi-16-day wave in the mesosphere and lower thermosphere region as revealed by meteor radar, Aura satellite, and MERRA2 reanalysis data from 2008 to 2017","authors":"Yun Gong,&nbsp;Zheng Ma,&nbsp;Chun Li,&nbsp;XieDong Lv,&nbsp;ShaoDong Zhang,&nbsp;QiHou Zhou,&nbsp;ChunMing Huang,&nbsp;KaiMing Huang,&nbsp;You Yu,&nbsp;GuoZhu Li","doi":"10.26464/epp2020033","DOIUrl":"10.26464/epp2020033","url":null,"abstract":"<p>This study presents an analysis of the quasi-16-day wave (Q16DW) at three stations in the middle latitudes by using a meteor radar chain in conjunction with Aura Microwave Limb Sounder temperature data and MERRA2 (Modern-Era Retrospective Analysis for Research and Applications, Version 2) reanalysis data from 2008 to 2017. The radar chain consists of three meteor radar stations located at Mohe (MH, 53.5°N, 122.3°E), Beijing (BJ, 40.3°N, 116.2°E), and Wuhan (WH, 30.5°N, 114.6°E). The Q16DW wave exhibits similar seasonal variation in the neutral wind and temperature, and the Q16DW amplitude is generally strong during winter and weak around summer. The Q16DW at BJ was found to have secondary enhancement around September in the zonal wind, which is rarely reported at similar latitudes. The latitudinal variations of the Q16DW in the neutral wind and temperature are quite different. The Q16DW at BJ is the most prominent in both neutral wind components among the three stations and the Q16DW amplitudes at MH and WH are comparable, whereas the wave amplitude in temperature decreases with decreasing latitude. The quasi-geostrophic refractive index squared at the three stations in the period from 2008 to 2017 was revealed. The results indicate that the Q16DW in the mesosphere and lower thermosphere (MLT) at MH has a limited contribution from the lower atmosphere. Around March and October, the Q16DW in the troposphere at BJ can propagate upward into the MLT region, whereas at WH, the contribution to the Q16DW in the MLT region is largely from the mesosphere.</p>","PeriodicalId":45246,"journal":{"name":"Earth and Planetary Physics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2020-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.26464/epp2020033","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47837613","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fine debris flows formed by the Orientale basin","authors":"YuZhen Cai,&nbsp;ZhiYong Xiao,&nbsp;ChunYu Ding,&nbsp;Jun Cui","doi":"10.26464/epp2020027","DOIUrl":"10.26464/epp2020027","url":null,"abstract":"<p>The prototype for investigations of formation mechanisms and related geological effects of large impact basins on planetary bodies has been the Orientale basin on the Moon. Its widespread secondaries, light plains, and near-rim melt flows have been well mapped in previous studies. Flow features are also widely associated with secondaries on planetary bodies, but their physical properties are not well constrained. The nature of flow features associated with large impact basins are critically important to understand the emplacement process of basin ejecta, which is one of the most fundamental processes in shaping the shallow crusts of planetary bodies. Here we use multisource remote sensing data to constrain the physical properties of flow features formed by the secondaries of the Orientale basin. The results suggest that such flows are dominated by centimeter-scale fine debris fines; larger boulders are not abundant. The shattering of target materials during the excavation of the Orientale basin, landing impact of ejecta that formed the secondaries, and grain comminution within the flows have substantially reduced particle sizes, forming the fine flows. The discovery of global-wide fine debris flows formed by large impact basins has profound implications to the interpretation of both previously-returned samples and remote sensing data.</p>","PeriodicalId":45246,"journal":{"name":"Earth and Planetary Physics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2020-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.26464/epp2020027","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41616780","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A normalized statistical study of Earth's cusp region based on nine-years of Cluster measurements","authors":"Chao Xiao,&nbsp;WenLong Liu,&nbsp;DianJun Zhang,&nbsp;Zhao Zhang","doi":"10.26464/epp2020031","DOIUrl":"10.26464/epp2020031","url":null,"abstract":"<p>Nine years (2001–2009) of data from the Cluster spacecraft are analyzed in this study of the Earth's mid- and high-altitude (2–9<i>R</i>\u0000 _E) cusp. Properties of the cusp region, and its location and size in the Solar Magnetic coordinate system, are studied statistically. The survey shows that (1) the relationships between <i>X</i> and <i>Z</i> are nearly linear for the poleward, equatorward boundaries and the center of the cusp; (2) the relationship between cusp width in the <i>X</i> direction and <i>Z</i> can be expressed by a quadratic function; (3) the cusp region is almost dawn-dusk symmetric for the cusp width in the <i>X</i> direction. Based on topology information, a new normalized statistical methodology is developed to organize the measurements of cusp crossings to obtain distributions of magnetic field and plasma parameters in the <i>XZ</i> plane. The statistical results show that (1) <i>B_x\u0000 </i> is mostly negative and <i>B_z\u0000 </i> is always negative; (2) proton velocity is found to be positive for <i>V_x\u0000 </i> and <i>V_z\u0000 </i> at low altitudes, while <i>V_x\u0000 </i> and <i>V_z\u0000 </i> are negative on the equator side and negative <i>V_x\u0000 </i> and positive <i>V_z\u0000 </i> on the pole side at high altitudes; (3) proton density is higher on the equator side than on the pole side. Results reported here will be useful in suggesting directions for future cusp research.\u0000</p>","PeriodicalId":45246,"journal":{"name":"Earth and Planetary Physics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2020-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44270456","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Modeling co-seismic thermal infrared brightness anomalies in petroliferous basins surrounding the North and East of the Qinghai–Tibet Plateau","authors":"Xin Zhang,&nbsp;LiFeng Zhang","doi":"10.26464/epp2020029","DOIUrl":"10.26464/epp2020029","url":null,"abstract":"<p>Co-seismic gas leakage usually occurs on the edge of seismic faults in petroliferous basins, and it may have an impact on the local environment, such as the greenhouse effect, which can cause thermal infrared brightness anomalies. Using wavelet transform and power spectrum estimation methods, we processed brightness temperature data from the Chinese geostationary meteorological satellite FY-C/E. We report similarities between the co-seismic thermal infrared brightness (CTIB) anomalies before, during and after earthquakes that occurred at the edges of the Sichuan, Tarim, Qaidam, and Junggar basins surrounding the North and East of the Qinghai–Tibet Plateau in western China. Additionally, in each petroliferous basin, the area of a single CTIB anomaly accounted for 50% to 100% of the basin area, and the spatial distribution similarities in the CTIB anomalies existed before, during and after these earthquakes. To better interpret the similarities, we developed a basin warming effect model based on geological structures and topography. The model suggests that in a petroliferous basin with a subsurface gas reservoir, gas leakage could strengthen with the increasing stress before, during, and even after an earthquake. The accumulation of these gases, such as the greenhouse gases CH₄ and CO₂, results in the CTIB anomalies. In addition, we conclude that the CTIB anomalies are strengthened by the high mountains (altitude ~5000 m) around the basins and the basins’ independent climatic conditions. This work provides a new perspective from which to understand the CTIB anomalies in petroliferous basins surrounding the North and East of the Qinghai–Tibet Plateau.\u0000</p>","PeriodicalId":45246,"journal":{"name":"Earth and Planetary Physics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2020-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42284987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Recent ionospheric investigations in China (2018–2019)","authors":"LiBo Liu,&nbsp;WeiXing Wan","doi":"10.26464/epp2020028","DOIUrl":"10.26464/epp2020028","url":null,"abstract":"<p>Since the release of the 2018 National Report of China on ionospheric research ( Liu LB and Wan WX, 2018) to the Committee on Space Research (COSPAR), scientists from Mainland China have made many new fruitful investigations of various ionospheric-related issues. In this update report, we briefly introduce more than 130 recent reports (2018–2019). The current report covers the following topics: ionospheric space weather, ionospheric structures and climatology, ionospheric dynamics and couplings, ionospheric irregularity and scintillation, modeling and data assimilation, and radio wave propagation in the ionosphere and sounding techniques.</p>","PeriodicalId":45246,"journal":{"name":"Earth and Planetary Physics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2020-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.26464/epp2020028","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46982644","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"3-D shear wave velocity structure in the shallow crust of the Tan-Lu fault zone in Lujiang, Anhui, and adjacent areas, and its tectonic implications","authors":"Cheng Li,&nbsp;HuaJian Yao,&nbsp;Yuan Yang,&nbsp;Song Luo,&nbsp;KangDong Wang,&nbsp;KeSong Wan,&nbsp;Jian Wen,&nbsp;Bin Liu","doi":"10.26464/epp2020026","DOIUrl":"10.26464/epp2020026","url":null,"abstract":"<p>The Tan-Lu fault zone is a large NNE-trending fault zone in eastern China. Investigations of the structures of the fault zone and its surrounding areas have attracted much attention. In this study, we used dense-array ambient noise tomography to construct a three-dimensional shear wave velocity model of shallow crust in an area about 80km × 70km in Lujiang, Anhui Province, eastern China. For approximately one month we collected continuous ambient noise signals recorded by 90 short-period seismographs in the region, and obtained the short-period Rayleigh wave empirical Green's functions between stations by the cross-correlation method; we also extracted 0.5–8 s fundamental mode Rayleigh wave group velocity and phase velocity dispersion curves. Based on the direct surface wave tomography method, we jointly inverted the group velocity and phase velocity dispersion data of all paths and obtained the 3-D shear wave velocity structure in the depth range of 0–5 km. The results revealed important geological structural features of the study area. In the north region, the sedimentary center of the Hefei Basin — the southwestern part of the Chaohu Lake — shows a significant low-velocity anomaly to a depth of at least 5 km. The southwestern and southeastern regions of the array are the eastern margin of the Dabie orogenic belt and the intrusion area of Luzong volcanic rocks, respectively, and both show obvious high-speed anomalies; the sedimentary area within the Tan-Lu fault zone (about 10 km wide) shows low-velocity anomalies. However, the volcanic rock intrusion area in the fault zone is shown as high velocity. Our shallow crustal imaging results reflect the characteristics of different structures in the study area, especially the high-speed intrusive rocks in the Tan-Lu fault zone, which were probably partially derived from the magmatic activity of Luzong volcanic basin. From the Late Cretaceous to Early Tertiary, the Tan-Lu fault zone was in a period of extensional activity; the special stress environment and the fractured fault zone morphology provided conditions for magma in the Luzong volcanic basin to intrude into the Tan-Lu fault zone in the west. Our 3-D model can also provide important information for deep resource exploration and earthquake strong ground motion simulation.</p>","PeriodicalId":45246,"journal":{"name":"Earth and Planetary Physics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2020-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41460560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Prediction of the thermospheric and ionospheric responses to the 21 June 2020 annular solar eclipse","authors":"Tong Dang,&nbsp;JiuHou Lei,&nbsp;WenBin Wang,&nbsp;MaoDong Yan,&nbsp;DeXin Ren,&nbsp;FuQing Huang","doi":"10.26464/epp2020032","DOIUrl":"10.26464/epp2020032","url":null,"abstract":"<p>On 21 June 2020, an annular solar eclipse will traverse the low latitudes from Africa to Southeast Asia. The highest latitude of the maximum eclipse obscuration is approximately 30°. This low-latitude solar eclipse provides a unique and unprecedented opportunity to explore the impact of the eclipse on the low-latitude ionosphere–thermosphere (I–T) system, especially in the equatorial ionization anomaly region. In this study, we describe a quantitative prediction of the impact of this upcoming solar eclipse on the I–T system by using Thermosphere–Ionosphere–Electrodynamics General Circulation Model simulations. A prominent total electron content (TEC) enhancement of around 2 TEC units occurs in the equatorial ionization anomaly region even when this region is still in the shadow of the eclipse. This TEC enhancement lasts for nearly 4.5 hours, long after the solar eclipse has ended. Further model control simulations indicate that the TEC increase is mainly caused by the eclipse-induced transequatorial plasma transport associated with northward neutral wind perturbations, which result from eclipse-induced pressure gradient changes. The results illustrate that the effect of the solar eclipse on the I–T system is not transient and linear but should be considered a dynamically and energetically coupled system.</p>","PeriodicalId":45246,"journal":{"name":"Earth and Planetary Physics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2020-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42874044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"An empirical model of the global distribution of plasmaspheric hiss based on Van Allen Probes EMFISIS measurements","authors":"JingZhi Wang,&nbsp;Qi Zhu,&nbsp;XuDong Gu,&nbsp;Song Fu,&nbsp;JianGuang Guo,&nbsp;XiaoXin Zhang,&nbsp;Juan Yi,&nbsp;YingJie Guo,&nbsp;BinBin Ni,&nbsp;Zheng Xiang","doi":"10.26464/epp2020034","DOIUrl":"10.26464/epp2020034","url":null,"abstract":"<p>Using wave measurements from the EMFISIS instrument onboard Van Allen Probes, we investigate statistically the spatial distributions of the intensity of plasmaspheric hiss waves. To reproduce these empirical results, we establish a fitting model that is a third-order polynomial function of <i>L</i>-shell, magnetic local time (MLT), magnetic latitude (MLAT), and <i>AE</i>*. Quantitative comparisons indicate that the model's fitting functions can reflect favorably the major empirical features of the global distribution of hiss wave intensity, including substorm dependence and the MLT asymmetry. Our results therefore provide a useful analytic model that can be readily employed in future simulations of global radiation belt electron dynamics under the impact of plasmaspheric hiss waves in geospace.\u0000</p>","PeriodicalId":45246,"journal":{"name":"Earth and Planetary Physics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2020-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49152882","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Paleoclimatic and provenance implications of magnetic parameters from the Miocene sediments in the Subei Basin","authors":"YouSheng Li,&nbsp;JiMin Sun,&nbsp;ZhiLiang Zhang,&nbsp;Bai Su,&nbsp;ShengChen Tian,&nbsp;MengMeng Cao","doi":"10.26464/epp2020030","DOIUrl":"10.26464/epp2020030","url":null,"abstract":"<p>Thick sediments from foreland basins usually provide valuable information for understanding the relationships between mountain building, rock denudation, and sediment deposition. In this paper, we report environmental magnetic measurements performed on the Miocene sediments in the Subei Basin, northeastern Tibetan Plateau. Our results show two different patterns. First, the bulk susceptibility and SIRM, ARM, and HIRM mainly reflect the absolute-concentration of magnetic minerals; all have increased remarkably since 13.7 Ma, related to provenance change rather than climate change. Second, the ratios of IRM_100mT/SIRM, IRM_100mT/IRM_30mT, and IRM_100mT/IRM_60mT, together with the redness and <i>S</i> ratio, reflect the relative-concentration of hematite, being climate-dependent. Their vertical changes correlate in general with the long-term Miocene climatic records of marine oxygen isotope variations, marked by the existence of higher ratios between 17 and 14 Ma. This may imply that global climate change, rather than uplift of the Tibetan Plateau, played a dominant role in the long-term climatic evolution of the Subei area from the early to middle Miocene.\u0000</p>","PeriodicalId":45246,"journal":{"name":"Earth and Planetary Physics","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2020-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.26464/epp2020030","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46083271","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}