Seismic Hazard Assessment Problem in a Big Data World     

Vladimir G. Kossobokov 《《地质学报》英文版》2018,92(Z1):269-269

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Comparison of split window algorithms to derive land surface temperature from satellite TIRS data     

Sajad Zareie  Kazem Rangzan  Hassan Khosravi  Vladimir Modestovich Sherbakov 《Arabian Journal of Geosciences》2018,11(14):391

Remote sensing data can be used as the basis for meteorological data. Due to the limitations of meteorological stations on the Earth, derivation of land surface temperature is one of the most important aspects of the remote sensing application in climatology studies. In the present study, Landsat-8 thermal infrared sensor data of the scene located over Khuzestan province with row/path of 165/38 were used to derive land surface temperature (LST). Normalized difference vegetation index (NDVI), fraction of vegetation cover, satellite brightness temperature, and land surface emissivity were calculated as the vital criteria to derive LSTs using the split window algorithms. LST determination was performed by nine different split window algorithms. Eventually, LST products were evaluated using ground-based measurements at the meteorological stations of the study area. The results showed that algorithm of Coll and Casselles had a highest accuracy with RMSE 1.97 °C, and Vidal’s method presented the lowest accuracy to derive LST with RMSE 4.11 °C. According to the results, regions with high density of vegetation and water resources have lowest diurnal temperature and regions with bare soils and low density of vegetation have a highest diurnal temperature. Results of the study indicated that LST algorithm accuracy is an important factor in the environmental and climate change studies.  相似文献   

First geophysical and shallow ice core investigation of the Kazbek plateau glacier,Caucasus Mountains     

Stanislav S. Kutuzov  Vladimir N. Mikhalenko  Alexi M. Grachev  Patrick Ginot  Ivan I. Lavrentiev  Anna V. Kozachek  Victoria V. Krupskaya  Alexey A. Ekaykin  Levan G. Tielidze  Pavel A. Toropov 《Environmental Earth Sciences》2016,75(23):1488

First-ever ice core drilling at Mt. Kazbek (Caucasus Mountains) took place in the summer of 2014. A shallow ice core (18 m) was extracted from a plateau at ~4500 m a.s.l. in the vicinity of the Mt. Kazbek summit (5033 m a.s.l.). A detailed radar survey showed that the maximum ice thickness at this location is ~250 m. Borehole temperature of ?7 °C was measured at 10 m depth. The ice core was analyzed for oxygen and deuterium isotopes and dust concentration. From the observed seasonal cycle, it was determined that the ice core covers the time interval of 2009–2014, with a mean annual snow accumulation rate of 1800 mm w. eq. Multiple melt layers have been detected. δ¹⁸O values vary from ?25 to ?5‰. The dust content was determined using a particle sizing and counting analyzer. The dust layers were investigated using scanning electron microscopy and X-ray diffraction analysis. Dust can be separated into two categories by its origin: local and distant. Samples reflecting predominantly local origin consisted mainly of magmatic rocks, while clay minerals were a characteristic of dust carried over large distances, from the deserts of the Middle East and Sahara. The calculated average dust flux over three years at Kazbek was of 1.3 mg/cm² a^?1. Neither δ¹⁸O nor dust records appear to have been affected by summer melting. Overall, the conditions on Kazbek plateau and the available data suggest that the area offers good prospects of future deep drilling in order to obtain a unique environmental record.  相似文献   

Gamma-Ray and High-Energy-Neutron Measurements on CORONAS-F during the Solar Flare of 28 October 2003     

Sergei N. Kuznetsov  Victoria G. Kurt  Boris Y. Yushkov  Karel Kudela  Vladimir I. Galkin 《Solar physics》2011,268(1):175-193

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Atmospheric chemistry on Venus, Earth, and Mars: Main features and comparison     

Vladimir A. Krasnopolsky 《Planetary and Space Science》2011,59(10):952-964

This paper deals with two common problems and then considers major aspects of chemistry in the atmospheres of Mars and Venus. (1) The atmospheres of the terrestrial planets have similar origins but different evolutionary pathways because of the different masses and distances to the Sun. Venus lost its water by hydrodynamic escape, Earth lost CO₂ that formed carbonates and is strongly affected by life, Mars lost water in the reaction with iron and then most of the atmosphere by the intense meteorite impacts. (2) In spite of the higher solar radiation on Venus, its thermospheric temperatures are similar to those on Mars because of the greater gravity acceleration and the higher production of O by photolysis of CO₂. O stimulates cooling by the emission at 15 μm in the collisions with CO₂. (3) There is a great progress in the observations of photochemical tracers and minor constituents on Mars in the current decade. This progress is supported by progress in photochemical modeling, especially by photochemical GCMs. Main results in these areas are briefly discussed. The problem of methane presents the controversial aspects of its variations and origin. The reported variations of methane cannot be explained by the existing data on gas-phase and heterogeneous chemistry. The lack of current volcanism, SO₂, and warm spots on Mars favor the biological origin of methane. (4) Venus’ chemistry is rich and covers a wide range of temperatures and pressures and many species. Photochemical models for the middle atmosphere (58-112 km), for the nighttime atmosphere and night airglow at 80-130 km, and the kinetic model for the lower atmosphere are briefly discussed.  相似文献   

Solutions and periodicity of satellite relative motion under even zonal harmonics perturbations     

Vladimir Martinuşi  Pini Gurfil 《Celestial Mechanics and Dynamical Astronomy》2011,111(4):387-414

Finding relative satellite orbits that guarantee long-term bounded relative motion is important for cluster flight, wherein a group of satellites remain within bounded distances while applying very few formationkeeping maneuvers. However, most existing astrodynamical approaches utilize mean orbital elements for detecting bounded relative orbits, and therefore cannot guarantee long-term boundedness under realistic gravitational models. The main purpose of the present paper is to develop analytical methods for designing long-term bounded relative orbits under high-order gravitational perturbations. The key underlying observation is that in the presence of arbitrarily high-order even zonal harmonics perturbations, the dynamics are superintegrable for equatorial orbits. When only J ₂ is considered, the current paper offers a closed-form solution for the relative motion in the equatorial plane using elliptic integrals. Moreover, necessary and sufficient periodicity conditions for the relative motion are determined. The proposed methodology for the J ₂-perturbed relative motion is then extended to non-equatorial orbits and to the case of any high-order even zonal harmonics (J _2n , n ≥ 1). Numerical simulations show how the suggested methodology can be implemented for designing bounded relative quasiperiodic orbits in the presence of the complete zonal part of the gravitational potential.  相似文献   

On the relation between steep monoclinal flexure zones and steep hydraulic gradients   总被引：1，自引：0，他引：1  

Yechieli Y  Kafri U  Wollman S  Lyakhovsky V  Weinberger R 《Ground water》2007,45(5):616-626

Steep hydraulic gradients are found in association with steep monoclinal flexures. However, the physics of the reduction of the hydraulic conductivity, which is responsible for the steep gradients, has seldom been studied. We present results of hydrological and mechanical modeling aiming to study the effect of such steep hydraulic gradients demonstrated in the Judea Group Aquifer system, Israel. The hydrological configuration of steep dips and anisotropy between flows parallel and perpendicular to the bedding planes was simulated using the FEFLOW code. It exhibited a situation whereby part of the flow is oblique to the bedding planes and therefore some steepening of the hydraulic gradients occurred due to actual conductivity reduction. However, this reduction is not enough to account for the steeper gradients observed. The effect of a deep-seated reverse fault under the monocline on the permeability distribution within the structure was examined by numerical mechanical simulations. It exhibited a compressional stress distribution in the steep part of the monocline, which, due to shortening and closure of joints and voids, is presumably responsible for a significant pressure-induced permeability reduction. This process by itself in a layered structure, including interlayering of thin marl layers, could be responsible for the steep hydraulic gradients in the steep part of the monocline.  相似文献   

A New Mantispid-Like Species of Rhachiberothinae(Neuroptera:Berothidae)from Baltic Amber,with a Critical Review of the Fossil Record of the Subfamily     

Vladimir N. Makarkin  and Janusz Kupryjanowicz 《《地质学报》英文版》2010,84(4):655-664

<正>Whalfera wiszniewskii sp.nov.is described from the Late Eocene Baltic amber.The genus Whalfera is considered as the only fossil genus confidently assigned to the Rhachlberothinae.Others previously placed in this subfamily belong to Paraberothinae(except perhaps for Oisea).The Late Eocene/present Rhachiberothinae and the Cretaceous Paraberothinae are considered to be the subfamilies of Berothidae.  相似文献   

Geophysical-geochemical investigation of fire-prone landfills     

Vladimir Frid  Dmitri Doudkinski  Gady Liskevich  Efim Shafran  Arie Averbakh  Nikolay Korostishevsky  Larisa Prihodko 《Environmental Earth Sciences》2010,60(4):787-798

This paper deals with the integration of electrical resistivity tomography and geochemical methods for studying four different fire-prone landfills. Landfill gas composition (CH₄, H₂S, O₂, CO, CO₂) and subsurface temperature were measured with the constant net 50 × 50 m from the depth 10–60 cm. 28 electrical resistivity tomography lines were surveyed, while Wenner and Sclumberger electrode arrays were employed for all measurements. At the studied sites the landfill gas and temperature measurements mapped gas and temperature anomalies over underground fire sources. 2D electrical resistivity tomography lines, performed over these anomalies, showed these fire sources as high-resistivity zones. The joint employment of the electrical imaging and geochemical survey seems to be a useful tool in carrying out diagnostic investigations at fire-prone landfills.  相似文献