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991.
B.?A.?KaganEmail author E.?V.?Sofina A.?A.?Timofeev 《Izvestiya Atmospheric and Oceanic Physics》2018,54(2):206-212
It is well known that, within the linear nonviscous equations of tidal dynamics, the amplitudes of oscillations of the barotropic and baroclinic tidal velocity components unlimitedly increase when approaching the critical latitude. It is also known that the linear equations of tidal dynamics with a constant and specified vertical eddy viscosity indicate the occurrence of significant tidal velocity shears in the near-bottom layer, which are responsible for increasing the baroclinic tidal energy dissipation, the turbulent kinetic energy, and the thickness of the bottom boundary layer. The first circumstance—the growth of the amplitudes of oscillations of the barotropic and baroclinic tidal velocity components—is due to the elimination in the original equations of small terms, which are small everywhere except for the critical latitude zone. The second circumstance—the occurrence of significant tidal velocity shears—is due to the fact that internal tidal waves, which induce the dissipation of the baroclinic tidal energy and the diapycnal diffusion, are either not taken into account or described inadequately. It is suggested that diapycnal diffusion can lead to the degeneration (complete or partial) of tidal velocity shears, with all the ensuing consequences. The aforesaid is confirmed by simulation results obtained using the QUODDY-4 high-resolution three-dimensional finite-element hydrostatic model along the 66.25° E section, which passes in the Kara Sea across the critical latitude. 相似文献
992.
S.?N.?KulichkovEmail author O.?Ye.?Popov K.?V.?Avilov I.?P.?Chunchuzov O.?G.?Chkhetiani A.?A.?Smirnov V.?I.?Dubrovin A.?A.?Mishenin 《Izvestiya Atmospheric and Oceanic Physics》2018,54(3):293-303
Results obtained from simulating the propagation of infrasonic waves from the Chelyabinsk meteoroid explosion observed on February 15, 2013, are given. The pseudodifferential parabolic equation (PDPE) method has been used for calculations. Data on infrasonic waves recorded at the IS31 station (Aktyubinsk, Kazakhstan), located 542.7 km from the likely location of the explosion, have been analyzed. Six infrasonic arrivals (isolated clearly defined pulse signals) were recorded. It is shown that the first “fast” arrival (F) corresponds to the propagation of infrasound in a surface acoustic waveguide. The rest of the arrivals (T1–T5) are thermospheric. The agreement between the results of calculations based on the PDPE method and experimental data is satisfactory. The energy E of the explosion has been estimated using two methods. One of these methods is based on the law of conservation of the acoustic pulse I, which is a product of the wave profile area S/2 of the signal under analysis and the distance to its source E I [kt] = 1.38 × 10–10 (I [kg/s])1.482. The other method is based on the relation between the energy of explosion and the dominant period T of recorded signal E T [kt] = 1.02 × (T [s]2/σ)3/2, where σ is the dimensionless distance determining the degree of nonlinear effects during the propagation of sound along ray trajectories. According to the data, the explosion energy E I,T ranges from 1.87 to 32 kt TNT. 相似文献
993.
The formation of a stationary (equilibrium) range in a wind-wave spectrum is investigated by numerical simulation. The equation of evolution of the wind-wave spectrum is solved using the exact calculation of the Hasselmann kinetic integral and involving various modifications of known parameterizations of the mechanisms of wave pumping by wind (In) and of wave dissipation (Dis). It is shown that it is these two mechanisms that are responsible for the shape of the stationary range of the wind-wave spectrum, whereas the nonlinear mechanism plays a stabilizing but subsidiary role. With an appropriate choice of mathematical representations for In and Dis, any known empirical shape of the stationary range of the spectrum can be obtained. During the calculations it is found that, for real wind waves, the known representations of In and Dis do not ensure the existence of the inertial interval required for Kolmogorov-type spectra formation due to the nonlinear interactions between waves. 相似文献
994.
Sukhanova I. N. Flint M. V. Sakharova E. G. Fedorov A. V. Makkaveev P. N. Nedospasov A. A. 《Oceanology》2018,58(6):802-816
Oceanology - Based on the material obtained in the spring–summer season of 2016, the composition and quantitative distribution of phytoplankton in the Ob estuary and over the Kara Sea shelf... 相似文献
995.
Korotaev S. M. Budnev N. M. Serdyuk V. O. Orekhova D. A. Kruglyakov M. S. Kiktenko E. O. Mirgazov R. R. Zurbanov V. L. Gorokhov Ju. V. Ryabov E. V. 《Izvestiya Atmospheric and Oceanic Physics》2018,54(11):1569-1594
Izvestiya, Atmospheric and Oceanic Physics - The vertical component of the electric field Ez in the hydrosphere is not contaminated by the telluric component and therefore can effectively be used... 相似文献
996.
Boyarskikh I. G. Agatova A. R. Kulikova A. I. Bakiyanov A. I. Skaptsov M. V. Mazeika J. 《Izvestiya Atmospheric and Oceanic Physics》2018,54(8):805-825
Izvestiya, Atmospheric and Oceanic Physics - Areas with large gradients and anomalous variations in geomagnetic and radiation fields have been revealed and mapped at the northwestern foot of the... 相似文献
997.
Garkusha A. S. Polyakov A. V. Timofeev Yu. M. Virolainen Ya. A. Kukharsky A. V. 《Izvestiya Atmospheric and Oceanic Physics》2018,54(9):1244-1248
Izvestiya, Atmospheric and Oceanic Physics - A new technique has been developed to obtain the total ozone content (TOC) under cloudy conditions from the spectra of outgoing thermal IR radiation... 相似文献
998.
Barinov V. V. Myglan V. S. Taynik A. V. Oidupaa O. Ch. Agatova A. R. Churakova O. V. 《Izvestiya Atmospheric and Oceanic Physics》2018,54(10):1449-1459
Izvestiya, Atmospheric and Oceanic Physics - Analytic data on anomalies of the tree-ring structure of Siberian larch on the transect, passing through the Russian part of the Altai-Sayan Mountain... 相似文献
999.
A.?Maestro-GonzálezEmail author P.?Bárcenas J.?T.?Vázquez V.?Díaz-del-Río 《Geo-Marine Letters》2008,28(1):53-64
Fractures associated with volcanic rock outcrops on the inner shelf of Alboran Island, Western Mediterranean, were mapped
on the basis of a side-scan sonar mosaic. Absolute maximum fracture orientation frequency is NW–SE to NNW–SSE, with several
sub-maxima oriented NNE–SSW, NE–SW and ENE–WSW. The origin of the main fracture systems in Neogene and Quaternary rocks of
the Alboran Basin (south Spain) appears to be controlled by older structures, namely NE–SW and WNW–ESE to NW–SE faults which
cross-cut the basement. These faults, pre-Tortonian in origin, have been reactivated since the early Neogene in the form of
strike-slip and extensional movements linked to the recent stress field in this area. Fracture analysis of volcanic outcrops
on the inner continental shelf of Alboran Island suggests that the shelf has been deformed into a narrow shear zone limited
by two NE–SW-trending, sub-parallel high-angle faults, the main orientation and density of which have been influenced by previous
WNW–ESE to NW–SE basement fractures. 相似文献
1000.
The results of decennial monitoring of the Caspian Sea were summarized, which allowed revealing the “pumping” of nutrients from the euphotic layer to deepwater depressions of the Central and Southern Caspian Sea. In parallel, in the deepwater depressions, growth of hypoxia to values of 0.2–0.5 ml O2/l proceeds. In 2006, hydrogen sulfide was registered in the near-bottom layer of the South Caspian Sea Basin. It is shown that the transformation of the hydrochemical structure was directed towards the conditions observed at the times of Bruevich (1933–1934), but no complete coincidence has yet been reached. 相似文献