Determining parameters of Moon’s orbital and rotational motion from LLR observations using GRAIL and IERS-recommended models     

Dmitry A. Pavlov  James G. Williams  Vladimir V. Suvorkin 《Celestial Mechanics and Dynamical Astronomy》2016,126(1-3):61-88

The aim of this work is to combine the model of orbital and rotational motion of the Moon developed for DE430 with up-to-date astronomical, geodynamical, and geo- and selenophysical models. The parameters of the orbit and physical libration are determined in this work from lunar laser ranging (LLR) observations made at different observatories in 1970–2013. Parameters of other models are taken from solutions that were obtained independently from LLR. A new implementation of the DE430 lunar model, including the liquid core equations, was done within the EPM ephemeris. The postfit residuals of LLR observations make evident that the terrestrial models and solutions recommended by the IERS Conventions are compatible with the lunar theory. That includes: EGM2008 gravitational potential with conventional corrections and variations from solid and ocean tides; displacement of stations due to solid and ocean loading tides; and precession-nutation model. Usage of these models in the solution for LLR observations has allowed us to reduce the number of parameters to be fit. The fixed model of tidal variations of the geopotential has resulted in a lesser value of Moon’s extra eccentricity rate, as compared to the original DE430 model with two fit parameters. A mixed model of lunar gravitational potential was used, with some coefficients determined from LLR observations, and other taken from the GL660b solution obtained from the GRAIL spacecraft mission. Solutions obtain accurate positions for the ranging stations and the five retroreflectors. Station motion is derived for sites with long data spans. Dissipation is detected at the lunar fluid core-solid mantle boundary demonstrating that a fluid core is present. Tidal dissipation is strong at both Earth and Moon. Consequently, the lunar semimajor axis is expanding by 38.20 mm/yr, the tidal acceleration in mean longitude is \(-25.90 {{}^{\prime \prime }}/\mathrm{cy}^2\), and the eccentricity is increasing by \(1.48\times 10^{-11}\) each year.  相似文献   

Simulating flood events at the Twin Ports of Duluth-Superior using a linked hydrologic-hydrodynamic framework     

Fitzpatrick  Lindsay  Titze  Daniel  Anderson  Eric J.  Beletsky  Dmitry  Kelley  John G. W. 《Ocean Dynamics》2023,73(7):433-447

Ocean Dynamics - Generally, ports in the North American Great Lakes are not supported with navigational guidance (water level, water temperature, currents, ice) by NOAA’s Great Lakes...  相似文献   

Modeling the ice-attenuated waves in the Great Lakes     

Bai  Peng  Wang  Jia  Chu  Philip  Hawley  Nathan  Fujisaki-Manome  Ayumi  Kessler  James  Lofgren  Brent M.  Beletsky  Dmitry  Anderson  Eric J.  Li  Yaru 《Ocean Dynamics》2020,70(7):991-1003

Ocean Dynamics - A partly coupled wave-ice model with the ability to resolve ice-induced attenuation on waves was developed using the Finite-Volume Community Ocean Model (FVCOM) framework and...  相似文献   

Physical mechanisms of submesoscale eddies generation: evidences from laboratory modeling and satellite data in the Black Sea     

Zatsepin  Andrey  Kubryakov  Arseny  Aleskerova  Anna  Elkin  Dmitry  Kukleva  Olga 《Ocean Dynamics》2019,69(2):253-266

Ocean Dynamics - The observed evidence of the implementation of three different mechanisms of the submesoscale eddies generation in the Black Sea previously studied by the field research and...  相似文献   

Solar internal rotation and dynamo waves: A two-dimensional asymptotic solution in the convection zone     

Gaetano Belvedere  Kirill Kuzanyan  Dmitry Sokoloff 《Journal of Astrophysics and Astronomy》2000,21(3-4):379-380

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Thermochronological insights into the structural contact between the Tian Shan and Pamirs,Tajikistan          下载免费PDF全文

Gilby Jepson  Stijn Glorie  Dmitry Konopelko  Jack Gillespie  Martin Danišík  Noreen J. Evans  Yunus Mamadjanov  Alan S. Collins 《地学学报》2018,30(2):95-104

Multi‐method thermochronology along the Vakhsh‐Surkhob fault zone reveals the thermotectonic history of the South Tian Shan–Pamirs boundary. Apatite U/Pb analyses yield a consistent age of 251 ± 2 Ma, corresponding to cooling below ~550–350°C, related to the final closure of the Palaeo‐Asian Ocean and contemporaneous magmatism in the South Tian Shan. Zircon (U–Th–Sm)/He ages constrain cooling below ~180°C to the end of the Triassic (~200 Ma), likely related either to deformation induced by the Qiangtang collision or to the closure of the Rushan Ocean. Apatite fission track thermochronology reveals two low‐temperature (<120°C) thermal events at ~25 Ma and ~10 Ma, which may be correlated with tectonic activity at the distant southern Eurasian margin. The late Miocene cooling is confirmed by apatite (U–Th–Sm)/He data and marks the onset of mountain building within the South Tian Shan that is ongoing today.  相似文献   

A modern analogue of the Pleistocene steppe‐tundra ecosystem in southern Siberia     

Milan Chytrý  Michal Horsk  Ji&#x;í Danihelka  Nikolai Ermakov  Dmitry A. German  Michal Hjek  Petra Hjkov  Martin Ko í  Svatava Kube&#x;ov  Pavel Lustyk  Jeffrey C. Nekola  Vra Pavelkov &#x;i nkov  Zdenka Preislerov  Philipp Resl  Milan Valachovi 《Boreas: An International Journal of Quaternary Research》2019,48(1):36-56

Steppe‐tundra is considered to have been a dominant ecosystem across northern Eurasia during the Last Glacial Maximum. As the fossil record is insufficient for understanding the ecology of this vanished ecosystem, modern analogues have been sought, especially in Beringia. However, Beringian ecosystems are probably not the best analogues for more southern variants of the full‐glacial steppe‐tundra because they lack many plant and animal species of temperate steppes found in the full‐glacial fossil record from various areas of Europe and Siberia. We present new data on flora, land snails and mammals and characterize the ecology of a close modern analogue of the full‐glacial steppe‐tundra ecosystem in the southeastern Russian Altai Mountains, southern Siberia. The Altaian steppe‐tundra is a landscape mosaic of different habitat types including steppe, mesic and wet grasslands, shrubby tundra, riparian scrub, and patches of open woodland at moister sites. Habitat distribution, species diversity, primary productivity and nutrient content in plant biomass reflect precipitation patterns across a broader area and the topography‐dependent distribution of soil moisture across smaller landscape sections. Plant and snail species considered as glacial relicts occur in most habitats of the Altaian steppe‐tundra, but snails avoid the driest types of steppe. A diverse community of mammals, including many species typical of the full‐glacial ecosystems, also occurs there. Insights from the Altaian steppe‐tundra suggest that the full‐glacial steppe‐tundra was a heterogeneous mosaic of different habitats depending on landscape‐scale moisture gradients. Primary productivity of this habitat mosaic combined with shallow snow cover that facilitated winter grazing was sufficient to sustain rich communities of large herbivores.  相似文献   

A new echiuran species Thalassema malakhovi (echiura) from New Zealand     

Dmitry V. Popkov 《新西兰海洋与淡水研究杂志》2013,47(3-4):379-383

A new echiuran Thalassema malakhovi, collected at 20 m depth off the Bay of Plenty, New Zealand, is described. The possibility of using the structure of the nephrostome for subgrouping Thalassema species is discussed. The generic diagnosis of Thalassema Pallas is given.  相似文献   

Numerical simulation of seismic waves in models with anisotropic formations: coupling Virieux and Lebedev finite-difference schemes   总被引：2，自引：0，他引：2  

Vadim Lisitsa  Vladimir Tcheverda  Dmitry Vishnevsky 《Computational Geosciences》2012,16(4):1135-1152

Anisotropy is widespread in the Earth’s interior. However, there is a number of models where anisotropic formations comprise as few as 10–20?% of the volume, and this includes fractured reservoirs, thin-layered packs, etc. while the major part of the medium is isotropic. In this situation, the use of computationally intense anisotropy-oriented approaches throughout the computational domain is prodigal. So this paper presents an original advanced finite-difference algorithm based on the domain decomposition technique with individual scheme used inside subdomains. It means that the standard staggered grid scheme or the Virieux scheme is used in the main part of the model which is isotropic, while the anisotropy-oriented Lebedev scheme is utilized inside domains with anisotropic formations. Finite-difference consistency conditions at the artificial interface where the schemes are coupled are designed to make the artificial reflections as low as possible, namely, for the second-order scheme, the third order of convergence of the reflection coefficients is proved.  相似文献   

Kobyashevite, Cu5(SO4)2(OH)6·4H2O, a new devilline-group mineral from the Vishnevye Mountains, South Urals, Russia     

Igor V. Pekov  Natalia V. Zubkova  Vasiliy O. Yapaskurt  Dmitriy I. Belakovskiy  Nikita V. Chukanov  Anatoly V. Kasatkin  Aleksey M. Kuznetsov  Dmitry Y. Pushcharovsky 《Mineralogy and Petrology》2013,107(2):201-210

A new mineral kobyashevite, Cu₅(SO₄)₂(OH)₆·4H₂O (IMA 2011–066), was found at the Kapital’naya mine, Vishnevye Mountains, South Urals, Russia. It is a supergene mineral that occurs in cavities of a calcite-quartz vein with pyrite and chalcopyrite. Kobyashevite forms elongated crystals up to 0.2 mm typically curved or split and combined into thin crusts up to 1?×?2 mm. Kobyashevite is bluish-green to turquoise-coloured. Lustre is vitreous. Mohs hardness is 2½. Cleavage is {010} distinct. D(calc.) is 3.16 g/cm³. Kobyashevite is optically biaxial (?), α 1.602(4), β 1.666(5), γ 1.679(5), 2 V(meas.) 50(10)°. The chemical composition (wt%, electron-microprobe data) is: CuO 57.72, ZnO 0.09, FeO 0.28, SO₃ 23.52, H₂O(calc.) 18.39, total 100.00. The empirical formula, calculated based on 18 O, is: Cu_4.96Fe_0.03Zn_0.01S_2.01O_8.04(OH)_5.96·4H₂O. Kobyashevite is triclinic, $ P\overline{\,1 } $ , a 6.0731(6), b 11.0597(13), c 5.5094(6)?Å, α 102.883(9)°, β 92.348(8)°, γ 92.597(9)°, V 359.87(7)?ų, Z?=?1. Strong reflections of the X-ray powder pattern [d,Å-I(hkl)] are: 10.84–100(010); 5.399–40(020); 5.178–12(110); 3.590–16(030); 2.691–16(20–1, 040, 002), 2.653–12(04–1, 02–2), 2.583–12(2–11, 201, 2–1–1), 2.425–12(03–2, 211, 131). The crystal structure (single-crystal X-ray data, R?=?0.0399) сontains [Cu₄(SO₄)₂(OH)₆] corrugated layers linked via isolated [CuO₂(H₂O)₄] octahedra; the structural formula is CuCu₄(SO₄)₂(OH)₆·4H₂O. Kobyashevite is a devilline-group member. It is named in memory of the Russian mineralogist Yuriy Stepanovich Kobyashev (1935–2009), a specialist on mineralogy of the Urals.  相似文献