On the Contribution of the Eddy Transport to the Annual Mean Heat Budget of the Upper Layer in the North Atlantic     

A. B. Polonsky  P. A. Sukhonos 《Izvestiya Atmospheric and Oceanic Physics》2018,54(5):507-514

According to Ocean Re-Analysis System 3 (ORA-S3) data, all components of the annual mean heat budget of the upper quasi-homogeneous ocean layer (UQL) in the North Atlantic for the period of 1959–2011 have been calculated and errors of these estimates have been determined. It has been shown that the contribution of the horizontal eddy diffusivity (estimated as a residual term of the UQL heat balance equation) to changes in the UQL annual mean temperature is significantly overestimated. This takes place mainly due to neglecting the covariances of seasonal fluctuations of current velocity vector components and UQL temperature gradients in calculations carried out with the use of annual average values. These covariances play an important role in the annual mean heat budget in some regions of the North Atlantic, especially in tropical latitudes. Changes in the annual average UQL temperature in the central and eastern parts of the North Atlantic are significantly affected by errors related to an inaccuracy of estimates of annual average heat fluxes on the ocean surface. The maximum contribution of the horizontal eddy diffusivity to the interannual variability of the UQL temperature is observed in the northwestern part of the North Atlantic and the region of the Subpolar Gyre.  相似文献   

Chemical and mineralogical characterization of the Mineo (Sicily,Italy) pallasite: A unique sample          下载免费PDF全文

A. Zucchini  M. Petrelli  F. Frondini  C. M. Petrone  P. Sassi  A. Di Michele  S. Palmerini  O. Trippella  M. Busso 《Meteoritics & planetary science》2018,53(2):268-283

The Mineo pallasite is characterized here for the first time. The only 42 g still available worldwide is part of the collection of the Department of Physics and Geology, University of Perugia. A multianalytical approach was used, joining field-emission scanning electron microscopy, Raman analysis, X-ray powder diffraction, electron-probe microanalysis, and laser ablation inductively coupled plasma mass spectrometry. Results highlighted that (1) the Mineo pallasite belongs to the Main Group pallasites; (2) the silicate component is essentially olivine, with no pyroxene component; (3) the olivine chemical composition varies in terms of both iron and trace elements; (4) the metal phase is essentially kamacite with the taenite mainly found in the plessite structure; (5) phosphide phases are present as schreibersite and barringerite. The observed compositional variability in olivines as well as their occurrence as both angular and rounded crystals suggest that the Mineo pallasite could have been derived from a large impact of a differentiated parent body with a larger solid body. The resulting pallasite conglomerate consists of the compositionally different olivines, likely coming from different areas of the same differentiated parent body, and the residual molten Fe-Ni.  相似文献   

On the Evolution of Balloon Satellite Motions in a Plane Restricted Three-Body Problem with Light Pressure     

A. V. Dobroslavskiy  P. S. Krasilnikov 《Astronomy Letters》2018,44(8-9):567-578

We investigate the evolution of high Earth satellite orbits under gravitational perturbations from the Sun and light pressure forces, without the Earth shadow effect. We present the disturbing function of the problem provided that the satellite is a sphere. The mean value of the disturbing function in the absence of resonances between the mean unperturbed motion of the satellite and the mean motion of the Sun has also been obtained. The semimajor axis of the satellite orbit and the mean value of the disturbing function are shown to be integrals of the averaged osculating equations. TheHill version of the problem, whereby the distance to the satellite is much smaller than the Earth–Sun distance, has been studied in detail: we have constructed the phase portraits of the oscillations at various parameters and described three types of quasiperiodic satellite trajectories—librational and rotational trajectories as well as Earth collision trajectories. Numerical simulations of trajectories have allowed the additional effects caused by light pressure to be described: the displacement of the bounded trajectory of the satellite as a whole relative to the trajectory of the classical three-body problem into a region more distant from the Sun.  相似文献   

Geodynamic Settings of the Formation of Microcontinents,Submerged Plateaus,and Nonvolcanic Islands within Continental Margins     

E.?P.?DubininEmail author 《Oceanology》2018,58(3):435-446

During breakup of the continental lithosphere, partial or complete separation of small continental blocks from the mainland frequently occurs, leading to the formation of microcontinents or partially separated submerged plateaus that advance toward the ocean, as well as to emergent nonvolcanic islands. The article reviews the geodynamic settings in which isolated blocks of continental crust can form. Depending on the thermomechanical conditions of continental rifting, such blocks may be preserved as emergent islands or as submerged blocks of continental crust.  相似文献   

Autonomous (Non-Plate-Tectonic) Geodynamics of the Pyrenees     

Shevchenko  V. I.  Guseva  T. V.  Dobrovolsky  I. P.  Krupennikova  I. S.  Lukk  A. A. 《Izvestiya Atmospheric and Oceanic Physics》2018,54(8):826-847

Izvestiya, Atmospheric and Oceanic Physics - The tectonic structure, seismicity, and modern geodynamics of the roughly EW-trending Pyrenees are considered based on the literature data. Geological...  相似文献   

Radiation from a Superbolide     

V.?V.?SvettsovEmail author  V.?V.?Shuvalov  O.?P.?Popova 《Solar System Research》2018,52(3):195-205

Numerical simulation of the destruction, evaporation, deceleration, and emission of the Chelyabinsk superbolide has been carried out. The model assumes that the main energy is radiated in the stage when the asteroid is already completely destroyed and does not have solidity (quasi-liquid approximation). The radiation transfer during the motion is taken into account in the approximation of radiative heat conductivity and volumetric emission. The distributions of temperatures and densities are obtained at the moments when the bolide is at different altitudes. The intensity of radiation at the Earth’s surface is calculated at certain times by solving the radiative transfer equation along the rays passing through the luminous region using the air and LL-chondrite vapor absorption coefficients. The features of superbolide radiation, the contribution of air and vapor to radiation, the size of the luminous region, and the radiation spectrum have been considered. The calculated efficiency of radiation—17% of the kinetic energy of a cosmic body—agrees with the results of observations. It is shown that due to anisotropy of the superbolide radiation, the determination of luminous efficiency from measurements can depend on the observation point. For estimations, the pointsource approximation can be used, but in general, the source luminous efficiency is unknown, and its location is determined with some error; therefore, numerical simulation is required to reliably estimate the consequences of space body falls.  相似文献   

Photospheric Spots and Flare on the Active Dwarf Star FR Cnc     

A. V. Kozhevnikova  V. P. Kozhevnikov  I. Yu. Alekseev 《Astrophysics》2018,61(1):30-40

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Development of a Software Package for Environmental Risk Assessment Based on Materials of Repeated Remote Surveys     

Viktorov  A. S.  Berezin  P. V.  Kapralova  V. N. 《Izvestiya Atmospheric and Oceanic Physics》2018,54(9):1320-1326

Izvestiya, Atmospheric and Oceanic Physics - This paper presents the development of a model version of a software package for analyzing the dynamics of dangerous exogenous processes in view of the...  相似文献   

Tropical Cyclone Genesis Potential Index for Bay of Bengal During Peak Post-Monsoon (October-November) Season Including Atmosphere-Ocean Parameters     

P. Suneeta 《Marine Geodesy》2018,41(1):86-97

Several studies on tropical cyclone genesis potential index (GPI) mainly using atmospheric parameters (relative/absolute vorticity, relative humidity, vertical wind shear, potential instability, vertical velocity etc.) have been reported earlier. Though the ocean plays a vital role in the genesis and intensification of cyclones, no ocean parameter has been included in most of the studies. In this study, we have made an attempt to develop a new GPI for Bay of Bengal during peak post-monsoon (October-November) season including upper ocean heat content (UOHC) using the data for the period 1995–2015. It is found that the new GPI is better correlated with the total number of depressions, cyclones and severe cyclones (TNDC) compared with the existing GPI which was developed for the north Indian Ocean and presently used by India Meteorological Department (IMD), New Delhi. The correlation has significantly enhanced (r=0.86:significant at >99% level) by using the first differences [year(0) –year(?1)] of the time series data. Since, the new GPI which considers atmosphere and ocean (UOHC) parameters, it appears to be more suitable for Bay of Bengal during the peak post-monsoon season.  相似文献   

Monitoring Anthropogenic Impact on Some Coastal Water Areas of the Black Sea Using Multispectral Satellite Imagery     

Bondur  V. G.  Vorobyev  V. E.  Zamshin  V. V.  Serebryany  A. N.  Latushkin  A. A.  Li  M. E.  Martynov  O. V.  Hurchak  A. P.  Grinchenko  D. V. 《Izvestiya Atmospheric and Oceanic Physics》2018,54(9):1008-1022

Izvestiya, Atmospheric and Oceanic Physics - The results of comprehensive monitoring of anthropogenic impact on some coastal water areas of the Black Sea are presented. Multispectral satellite...  相似文献