基于GIS模拟的Votkinsk水库流域积雪和融化过程（英文）     

Sergey V.PYANKOV  Andrey N.SHIKHOV  Nikolay A.KALININ  Eugene M.SVIYAZOV 《地理学报(英文版)》2018,(2)

Coupled hydrological and atmospheric modeling is an efficient method for snowmelt runoff forecast in large basins. We use short-range precipitation forecasts of mesoscale atmospheric Weather Research and Forecasting(WRF) model combining them with ground-based and satellite observations for modeling snow accumulation and snowmelt processes in the Votkinsk reservoir basin(184,319 km2). The method is tested during three winter seasons(2012–2015). The MODIS-based vegetation map and leaf area index data are used to calculate the snowmelt intensity and snow evaporation in the studied basin. The GIS-based snow accumulation and snowmelt modeling provides a reliable and highly detailed spatial distribution for snow water equivalent(SWE) and snow-covered areas(SCA). The modelling results are validated by comparing actual and estimated SWE and SCA data. The actual SCA results are derived from MODIS satellite data. The algorithm for assessing the SCA by MODIS data(ATBD-MOD 10) has been adapted to a forest zone. In general, the proposed method provides satisfactory results for maximum SWE calculations. The calculation accuracy is slightly degraded during snowmelt periods. The SCA data is simulated with a higher reliability than the SWE data. The differences between the simulated and actual SWE may be explained by the overestimation of the WRF-simulated total precipitation and the unrepresentativeness of the SWE measurements(snow survey).  相似文献   

Trace element and PGE distribution in layered ferromanganese crusts     

A. M. Asavin  L. I. Anikeeva  V. A. Kazakova  S. I. Andreev  D. A. Sapozhnikov  I. A. Roshchina  L. N. Kogarko 《Geochemistry International》2008,46(12):1179-1205

A collection of layered ferromanganese ores (27 samples) from the Atlantic and Pacific oceans was studied. Trace element and PGE contents were determined layer-by-layer (up to 10 microlayers) in 13 of these samples.The trace, rare earth, and platinum group element distributions, including their layer-to-layer variations, were compared in hydrogenic and hydrothermal crusts from different regions. It was found that the main PGE variations (by a factor of 10–50) are related to their layer-to-layer variations within a given ore field.The distributions of PGE and trace elements are strongly heterogeneous, which is related, first, to different contents of the elements in the layers of different age in ferromanganese crusts (FMC) and, second, to the observed regional heterogeneity and influence of hydrothermal fluids. Geochemical data indicate that CFC formation was mainly caused by the hydrochemical precipitation of material from seawater. This process was accompanied by diagenetic phenomena, water-rock interaction, and influence of volcanic and hydrothermal sources.  相似文献   

Characteristics of Coronal Alfvén Waves Deduced from Helios Faraday Rotation Measurements     

Andreev  V. E.  Efimov  A. I.  Samoznaev  L. N.  Chashei  I. V.  Bird  M. K. 《Solar physics》1997,176(2):387-402

A statistical study of Faraday rotation fluctuations (FRF) has been performed using polarization angle data of S-band (f = 2.3 GHz) radio spacecraft signals. The measurements were recorded during the recurring superior conjunctions of the Helios probes, during which the solar proximate point of the radio ray path reached heliocentric distances between 3 and 34 R. The most commonly found temporal FRF spectra are power laws with an average spectral index 1.5 over the frequency range from 1 mHz < v < 10 mHz. The FRF variance decreases with heliocentric distance, the falloff exponent being 8 for R < 6 R and 3 for distances 8 < R < 6 R < 16 R. The results are interpreted under the assumption that the FRF are produced by Alfvén waves propagating in the coronal plasma. For the applicable range of heliocentric distances it is shown that Alfvén waves are in a regime of free propagation and probably transfer much of their energy to the kinetic energy of the solar wind. The spatial power spectrum of magnetic field fluctuations is inferred to be strongly anisotropic, the irregularities extending along the background magnetic field with axial ratios of the order of 10.  相似文献   

Chromium solubility in anhydrous Phase B     

Luca Bindi  Ekaterina A. Sirotkina  Andrey V. Bobrov  Fabrizio Nestola  Tetsuo Irifune 《Physics and Chemistry of Minerals》2016,43(2):103-110

The crystal structure and chemical composition of a crystal of (Mg_14?x Cr _x )(Si_5?x Cr _x )O₂₄ (x ≈ 0.30) anhydrous Phase B (Anh-B) synthesized in the model system MgCr₂O₄–Mg₂SiO₄ at 12 GPa and 1600 °C have been investigated. The compound was found to be orthorhombic, space group Pmcb, with lattice parameters a = 5.900(1), b = 14.218(2), c = 10.029(2) Å, V = 841.3(2) Å³ and Z = 2. The structure was refined to R ₁ = 0.065 using 1492 independent reflections. Chromium was found to substitute for both Mg at the M3 site (with a mean bond distance of 2.145 Å) and Si at the octahedral Si1 site (mean bond distance: 1.856 Å), according to the reaction Mg²⁺ + Si⁴⁺ = 2Cr³⁺. Such substitutions cause a reduction in the volume of the M3 site and an increase in the volume of the Si-dominant octahedron with respect to the values typically observed for pure Anh-B and Fe²⁺-bearing Anh-B. Taking into account that Cr³⁺ is not expected to be Jahn–Teller active, it appears that both the Cr³⁺–for–Mg and Cr³⁺–for–Si substitutions in the Anh-B structure decrease the distortion of the octahedra. Electron microprobe analysis gave the Mg_13.66(8)Si_4.70(6)Cr_0.62(4)O₂₄ stoichiometry for the studied phase. The successful synthesis of this phase provides new information for the possible mineral assemblages occurring in the Earth’s deep upper mantle and shed new light on the so-called X discontinuity that has been observed at 275–345 km depth in several subcontinental and subduction zone environments.  相似文献   

3D mineralogical mapping of the Kovdor phoscorite–carbonatite complex (Russia)     

Julia A. Mikhailova  Andrey O. Kalashnikov  Victor A. Sokharev  Yakov A. Pakhomovsky  Nataly G. Konopleva  Victor N. Yakovenchuk  Ayya V. Bazai  Pavel M. Goryainov  Gregory Yu. Ivanyuk 《Mineralium Deposita》2016,51(1):131-149

  相似文献   

Wind effects on the upwelling variability in the coastal zone of Primorye (the northwest of the Sea of Japan)     

I. A. Zhabin  E. V. Dmitrieva  T. R. Kil’matov  A. G. Andreev 《Russian Meteorology and Hydrology》2017,42(3):181-188

The variability of upwelling events in the coastal zone of Primorye in the northwestern part of the Sea of Japan is studied using the SeaWinds/QuikSCAT scatterometer wind data for the period of 1999-2009. The intensity of upwelling is defined by the wind-induced offshore Ekman transport (the upwelling index). It was found that along the southern coast of Primorye upwelling events occur from September to March (April). The winter monsoon period is the most favorable for the upwelling development. In the eastern part of the coastal zone of Primorye upwelling is observed in transitional seasons between winter and summer monsoon (February-April and September-October). On the northeastern coast of Primorye, the upwelling season is from August to October (November). The common feature of the coastal zone of Primorye is a wind-driven upwelling in autumn (September-October). The interannual variability of winter upwelling along the southern coast of Primorye is related to the East Asia high pressure center (the Siberian High). The upwelling intensifies in the years with positive air pressure anomalies in the Siberian High and weakens in the years with negative anomalies.  相似文献   

Methodology of the experimental study of the state of spent nuclear fuel on the bottom of arctic seas     

V. N. Soyfer  V. A. Goryachev  D. V. Andreev  I. R. Barabanov  A. P. Borisov  Yu. N. Zhukov  E. A. Yanovich 《Oceanology》2010,50(4):600-612

A methodology of experimental simulation of the state of spent nuclear fuel that is situated on the sea bottom as a result of some catastrophes or dumping is developed. Data on long-term (more than 2000 days) experiments on the estimation of the ⁸⁵Kr and ¹³⁷Cs release rate from spent nuclear fuel (fragments of irradiated UO₂ pellets) were first obtained; these estimates prove the correctness of the hypothesis put forward by us in the early 1990s concerning an earlier ⁸⁵Kr release (by one order of magnitude higher than that of ¹³⁷Cs) as compared to other fission fragments in the case of the loss of integrity of a fuel containment as a result of corrosion on the sea bottom. The method and technique of the onboard ⁸⁵Kr and ¹³⁷Cs sampling and extraction (as well as the sampling of tritium, a product of triple ²³⁵U fission) and their radiometric analysis at coastal laboratories are developed. Priority data on the ⁸⁵Kr background in the bottom layers of the Barents and Kara Seas and the ¹³⁷Cs and ³H in these seas (state of 2003) are presented. Models necessary for the estimation of the dilution of the fission products of spent nuclear fuel and their transport on the bottom in accident and dumping regions are developed. An experimental method for the examination of the state of spent nuclear fuel on the sea bottom (1 expedition each 2–3 years) by the ⁸⁵Kr release into the environment (a leak tracer) is proposed; this release is an indicator of the destruction of a fuel containment and the release of products of spent nuclear fuel in the case of ²³⁵UO₂ corrosion in sea water.  相似文献   

Study of variable stars associated with maser sources: G025.65+1.05     

Andrey M.Sobolev  Anastasia P.Bisyarina  Stanislav Yu.Gorda  Andrey M.Tatarnikov 《天文和天体物理学研究(英文版)》2019,(3)

We report variation of K-band infrared(IR) emission in the vicinity of the G025.65+1.05 water and methanol maser source. New observational data were obtained with the 2.5 m telescope at the Caucasian Mountain Observatory(CMO) of Moscow State University on 2017–09–21 during a strong water maser flare. We found that the IR source situated close to the maser position had decreased brightness in comparison to archive data. This source is associated with a massive young stellar object(MYSO) corresponding to the compact IR source IRAS 18316–0602(RAFGL 7009 S). A similar decrease in K-brightness of the IR source close to the maser position was observed in March 2011 when the water maser experienced a period of increased activity. The dips in MYSO brightness can be related to the maser flare phases. Maser flares that are concurrent with dips in the IR emission can be explained if the lower IR radiation field enables a more efficient sink for the pumping cycle by allowing IR photons to escape the maser region.  相似文献   

PGE geochemical constraints on the origin of the Ni-Cu-PGE sulfide mineralization in the Suoi Cun intrusion,Cao Bang province,Northeastern Vietnam     

Tatyana V. Svetlitskaya  Nadezhda D. Tolstykh  Andrey E. Izokh  Phuong Ngo Thi 《Mineralogy and Petrology》2015,109(2):161-180

  相似文献   

The dynamics of demographic indicators in Russia for the last half-century     

E. M. Andreev  A. G. Gamburtsev 《Izvestiya Atmospheric and Oceanic Physics》2010,46(8):915-924

This paper analyzes demographic data (the time series of the number of births and deaths for over 50 years in the 20th and 21st centuries). The properties of the time series are revealed, and some of them are explained. A comparison of data for men and women has resulted in the revelation that seasonal changes for women are more strongly evident than for men. The possible causes for the differences between the time series of the number of deceased men and women are discussed.  相似文献