Instability of the thermal bar formed in a gravity current     

Bukreev  V. I.  Gavrilov  N. V. 《Doklady Earth Sciences》2010,430(1):151-154

The results of experiments concerning fresh water at the temperature more than 4°C released along a free surface into water with a temperature less than 4°C are presented. As a result of Relay-Taylor instability caused by the nonmonotonic dependence of water density on the temperature, the denser water initially sank to the inclined bottom. At the same time, a vertical front separating water masses less and greater than 4°C formed. In limnology such an effect is called the “thermal bar.” Under certain conditions along with the Relay-Taylor instability, the Kelvin-Helmholtz instability tending to destroy the vertical front was also observed. Corresponding illustrations are presented.  相似文献   

Modeling Seasonal Variations in the Intensity of Internal Gravity Waves in the Lower Thermosphere     

Gavrilov  N. M.  Popov  A. A. 《Izvestiya Atmospheric and Oceanic Physics》2022,58(1):68-79

Izvestiya, Atmospheric and Oceanic Physics - An updated numerical model of the propagation of a set of spectral harmonics of internal gravity waves (IGWs) in the inhomogeneous atmosphere from the...  相似文献   

Annual and seasonal variability of precipitation in Vojvodina,Serbia     

Ivana Tošić  Ivana Hrnjak  Milivoj B. Gavrilov  Miroslava Unkašević  Slobodan B. Marković  Tin Lukić 《Theoretical and Applied Climatology》2014,117(1-2):331-341

Annual and seasonal variability of precipitation observed at 92 stations in Vojvodina (Serbia) were analyzed during the period 1946–2006. The rainfall series were examined by means of the empirical orthogonal functions (EOF). The first set of singular vectors explains from 68.8 % (in summer) to 81.8 % (in winter) of the total variance. The temporal variability of the time series associated with the main EOF configurations (the principal components, PCs) was examined using the Mann–Kendall test and the spectral analysis. The time series of PC1 revealed decreasing trend in the winter and spring precipitation and increasing trend in the autumn, summer, and annual precipitation. The relationships between the first PC and circulation patterns, such as the North Atlantic Oscillation (NAO), the East Atlantic (EA) pattern, and East Atlantic/West Russia pattern, were also investigated. The PC1, displaying temporal behavior of the first mode, demonstrated evident correspondence with the NAO index in analysis of the annual, winter, and autumn precipitation. Power spectra of the PC1 show statistically significant oscillations of about 3.3 years for the spring precipitation and about 8 and 15 years for the winter precipitation. Comparisons with spectral analysis of authors for some regions in Europe, most of them in the Mediterranean domain, show that similar periodicities are detected.  相似文献   

Dependence of D-Region Perturbations of the Midlatitude Ionosphere on the Spectral Composition of the X-Ray Radiation of Solar Flares According to Experimental Data     

Gavrilov  B. G.  Poklad  Yu. V.  Ryakhovsky  I. A.  Ermak  V. M. 《Geomagnetism and Aeronomy》2022,62(1-2):98-103

Geomagnetism and Aeronomy - An experimental study was made of the dependence of the electron-density perturbations in the D?regions of the midlatitude ionosphere during solar flares on the...  相似文献   

The State and Dynamics of the Ionosphere from Synchronous Records of ULF/VLF and HF/VHF Radio Signals at Geophysical Observatory “Mikhnevo”     

Ryakhovskii  I. A.  Gavrilov  B. G.  Poklad  Yu. V.  Bekker  S. Z.  Ermak  V. M. 《Izvestiya Physics of the Solid Earth》2021,57(5):718-730

Izvestiya, Physics of the Solid Earth - Abstract—Studying the spatiotemporal dynamics of the disturbances in the atmosphere, upper, and lower ionosphere requires integrated investigation of...  相似文献   

Satellite Geological Indication of Morphostructural Elements of the Coasts and Bottom of Adjacent Water Areas (Peter the Great Bay,Sea of Japan)     

Gavrilov  A. A. 《Oceanology》2021,61(4):555-568

Oceanology - The implementation of satellite geological investigations within the continent–Sea of Japan transition zone in Southern Primorye has made it possible to establish series,...  相似文献   

Integration of the shallow water equations in a plane geometry using semi-Lagrangian and Eulerian schemes     

M. B. Gavrilov 《Meteorology and Atmospheric Physics》1997,62(3-4):141-160

Summary Extended integrations of semi-Lagrangian and Eulerian shallow water primitive equation models are performed. The semi-Lagrangian model used the semi-implicit two-time-level scheme. The Eulerian model used a conserving nonlinear advection scheme.For low resolution and longer integrations, difficulties were encountered with the semi-Lagrangian model which were absent in the Eulerian model. These difficulties are discussed.With 14 Figures  相似文献   

Earthworm-based automatic system for real-time calculation of local earthquake source parameters     

A. A. Stepnov  A. V. Konovalov  A. V. Gavrilov  K. A. Manaychev 《Seismic Instruments》2017,53(4):267-279

Experience in introduction of an automatic system of earthquake source parameter calculation based on an existing seismic network is described. Open source software products for automatic seismic data processing are reviewed. Methods for real-time waveform stream processing are discussed in detail. Parameters of some subroutines of the system are described. Information flows and data life cycle in the developed automatic system are outlined. Earthquake location errors in the system are analyzed. The detection capability of seismic networks is evaluated.  相似文献   

Technologies of preliminary data processing for multidisciplinary geophysical monitoring and a case study of their application in the Kamchatka geoacoustic observation system     

V. A. Gavrilov  A. V. Desherevskii  E. V. Poltavtseva  A. Ya. Sidorin 《Seismic Instruments》2017,53(4):296-308

The problems and procedures for obtaining high quality results of multidisciplinary geophysical monitoring at the stage of preliminary data processing are considered. The case study of solving different technical problems during the long-term multidisciplinary borehole geophysical observations at the Petropavlovsk- Kamchatsky geodynamic research area is described. The algorithms for preliminary data processing and flawed data discard combining automated approaches and expert screening developed by the authors are presented. Suppression of quasi-regular disturbances is especially important in the studies of interrelations between geoacoustic, electromagnetic, and meteorological processes and seismicity because of the clear diurnal periodicity in all these processes that significantly complicates the signal extraction from the noise. The key technical, organizational, and methodical measures aimed at improving the data should be provided at the project planning stage of the measurement system. The optimal selection and reasoned application of special procedures for data preprocessing can crucially affect the research results.  相似文献   

Numerical simulation of the influence of stationary mesoscale orographic waves on the meridional circulation and ozone fluxes in the middle atmosphere     

N. M. Gavrilov  A. V. Koval  A. I. Pogoreltsev  E. N. Savenkova 《Geomagnetism and Aeronomy》2014,54(3):381-387

The authors’ parameterization of the dynamic and thermal action of stationary orographic waves generated by the Earth’s surface relief is included into the model of general circulation of the middle and upper atmosphere. Numerical simulation of the general circulation in the troposphere and stratosphere was performed and the influence of stationary orographic waves propagating upward from the Earth’s surface on the meridional and vertical velocity was studied. It is shown that the allowance for the dynamic and thermal action of these waves in the numerical model leads to changes by up to 20–30% in the meridional circulation and ozone fluxes associated with it at heights of the ozone layer maximum.  相似文献