共查询到20条相似文献，搜索用时 937 毫秒
1.
E. A. Sharkov 《Izvestiya Atmospheric and Oceanic Physics》2011,47(9):1057-1071
The generation and evolution of atmospheric catastrophes (tropical cyclones) represents a very serious and still unresolved
problem for mankind. The existing physical hypotheses and theoretical approaches which form the basis for a number of space
programs on the investigation of physical conditions for the genesis and evolution of tropical cyclones are critically analyzed.
The most significant stages of the history of development of the scientific aspects and concepts about tropical cyclones,
which are reflected in the pages of the Investigation of the Earth from the Space journal, are observed. The significance and role of remote (optical, infrared, and microwave) sensing in the evolution of
scientific views are analyzed. The fundamental contribution which Russian researchers and, first of all, specialists of the
Space Research Institute, Russian Academy of Sciences, as well as Russian developers of space missions and remote instrumentation,
have made to the present-day understanding of the problem and to the formation of the present-day image of microwave remote
sensing (RS) of the excited atmosphere is emphasized. 相似文献
2.
An overview on the helicity of the velocity field and the role played by this concept in modern research in the field of geophysical fluid dynamics and dynamic meteorology is given. Different (both previously known in the literature and first presented) formulations of the equation of helicity balance in atmospheric motions (including those with allowance for effects of air compressibility and Earth’s rotation) are brought together. Equations and relationships are given which are valid in different approximations accepted in dynamic meteorology: Boussinesq approximation, quasi-static approximation, and quasi-geostrophic approximation. Emphasis is placed on the analysis of helicity budget in large-scale quasi-geostrophic systems of motion; a formula for the helicity flux across the upper boundary of the nonlinear Ekman boundary layer is given, and this flux is shown to be exactly compensated for by the helicity destruction inside the Ekman boundary layer. 相似文献
3.
M. A. Tolstykh D. B. Kiktev R. B. Zaripov M. Yu. Zaichenko V. V. Shashkin 《Izvestiya Atmospheric and Oceanic Physics》2010,46(2):133-143
Simulation of the atmospheric circulation on the seasonal scale with the new version of the global semi-Lagrangian model is
considered. The new version includes land surface processes parameterization taking into account influence of the vegetation
and also freezing and melting of soil moisture. The new version also includes improved parameterization for short and long
wave radiation, cloudiness and atmospheric boundary layer. 相似文献
4.
I. P. Chunchuzov S. N. Kulichkov O. E. Popov R. Waxler J. Assink 《Izvestiya Atmospheric and Oceanic Physics》2011,47(5):540-557
A model of anisotropic fluctuations forming in wind velocity and air temperature in a stably stratified atmosphere is described. The formation mechanism of these fluctuations is associated with the cascade transport of energy from sources of atmospheric gravity waves to wave disturbances with shorter vertical scales (than the scales of the initial disturbances generated by the sources) and, at the same time, with longer horizontal scales. This model is used to take into account the effects of infrasonic-wave scattering from anisotropic inhomogeneities of the effective sound speed in the atmosphere. Experimental data on the stratospheric, mesospheric, and thermospheric arrivals of signals (generated by explosion sources such as surface explosions and volcanoes) in the zones of acoustic shadow are interpreted on the basis of the results of calculations of the scattered infrasonic field in the context of the parabolic equation. The signals calculated with consideration for the fine structure of wind velocity and air temperature are compared with the signals observed in a shadow zone. The possibility to acoustically sound this structure at heights of both the middle and upper atmospheres is discussed. 相似文献
5.
6.
7.
HENNING RODHE 《地球，A辑:动力气象学与海洋学》1999,51(1):110-122
8.
9.
The complexity of the laws of dynamics governing 3-D atmospheric flows associated with incomplete and noisy observations make the recovery of atmospheric dynamics from satellite image sequences very difficult. In this paper, we address the challenging problem of estimating physical sound and time-consistent horizontal motion fields at various atmospheric depths for a whole image sequence. Based on a vertical decomposition of the atmosphere, we propose a dynamically consistent atmospheric motion estimator relying on a multilayer dynamic model. This estimator is based on a weak constraint variational data assimilation scheme and is applied on noisy and incomplete pressure difference observations derived from satellite images. The dynamic model is a simplified vorticity-divergence form of a multilayer shallow-water model. Average horizontal motion fields are estimated for each layer. The performance of the proposed technique is assessed using synthetic examples and using real world meteorological satellite image sequences. In particular, it is shown that the estimator enables exploiting fine spatio-temporal image structures and succeeds in characterizing motion at small spatial scales. 相似文献
10.
Gorchakov G. I. Kadygrov E. N. Kortunova Z. V. Isakov A. A. Karpov A. V. Kopeikin V. M. Miller E. A. 《Izvestiya Atmospheric and Oceanic Physics》2008,44(1):100-106
The influence of a solar eclipse on solar-radiation fluxes, meteorological parameters, turbulence characteristics, and vertical temperature profiles in the atmospheric boundary layer is analyzed. Air-temperature variations caused by an eclipse and time delays of these variations with respect to the onset of the total-eclipse phase in the atmospheric surface and boundary layers are determined. The influence of a solar eclipse on the turbulent kinetic energy, turbulent heat flux, and variance and spectral density of the power of air-temperature pulsations are estimated. Variations in aerosol parameters and concentrations of light ions during a total solar eclipse are discussed. 相似文献
11.
A. I. Pogorel’tsev 《Izvestiya Atmospheric and Oceanic Physics》2007,43(4):423-435
A number of numerical experiments were performed with the use of the middle and upper atmosphere model (MUAM). In these experiments, the atmospheric response to an external excitation in the troposphere was calculated and internal stratospheric vacillations caused by the interaction of stationary planetary waves (SPWs) with the zonal mean flow were modeled. The MUAM is shown to well reproduce the known high-frequency global resonance responses of the atmosphere to an external excitation. The results of modeling show that the stratospheric vacillations caused by the interaction of SPWs and the mean flow are responsible for the generation of low-frequency normal modes in the lower and middle atmosphere. The activity of normal atmospheric modes in the troposphere and stratosphere is noted to increase simultaneously with the development of sudden stratospheric warmings. However, in order to understand which process is primary, an additional analysis of the results of numerical experiments and stratospheric data is necessary. It is inferred that, for an adequate modeling of stratospheric vacillation cycles, atmospheric general circulation models must be capable of reproducing global resonance properties of the atmosphere. 相似文献
12.
L. Kh. Ingel 《Izvestiya Atmospheric and Oceanic Physics》2014,50(1):61-65
Attention is focused on a positive feedback that may play a significant role in intense vortices, such as tornadoes and, probably, tropical cyclones: rotation suppresses turbulence which, in turn, may intensify rotation. Some simple models illustrate this phenomenon. 相似文献
13.
I. P. Chunchuzov S. N. Kulichkov P. P. Firstov 《Izvestiya Atmospheric and Oceanic Physics》2013,49(3):258-270
The nonlinear propagation of acoustic pulses from a point source of an explosive character (surface explosion or volcano) throughout the atmosphere with stratified wind-velocity and temperature inhomogeneities is studied. The nonlinear distortions of acoustic pulse and its transformation into an N-wave during its propagation to the upper atmosphere are analyzed in the context of a modified Burgers’ equation which takes into account a geometric ray-tube divergence simultaneously with an increase in both nonlinear and dissipative effects with height due to a decrease in atmospheric density. The problem of reflection of a spherical N-wave from an atmospheric inhomogeneous layer with model vertical wind-velocity and temperature fluctuations having a vertical spectrum that is close to that observed within the middle atmosphere is considered. The relation between the parameters (form, length, frequency spectrum, and intensity) of signals reflected from an atmospheric inhomogeneous layer and the parameters of the atmospheric fine layered structure at reflection heights is analyzed. The theoretically predicted forms of signals reflected from stratified inhomogeneities within the stratosphere and the lower thermosphere are compared to the observed typical forms of both stratospheric and thermospheric arrivals from surface explosions and volcanoes in the zones of an acoustic shadow. 相似文献
14.
Muyin Wang Nicholas A. Bond James E. Overland 《Deep Sea Research Part II: Topical Studies in Oceanography》2007,54(23-26):2543
A comparative analysis was conducted on climate variability in four sub-arctic seas: the Sea of Okhotsk, the Bering Sea shelf, the Labrador Sea, and the Barents Sea. Based on data from the NCEP/NCAR reanalysis, the focus was on air–sea interactions, which influence ice cover, ocean currents, mixing, and stratification on sub-seasonal to decadal time scales. The seasonal cycles of the area-weighted averages of sea-level pressure (SLP), surface air temperature (SAT) and heat fluxes show remarkable similarity among the four sub-arctic seas. With respect to variation in climate, all four seas experience changes of comparable magnitude on interannual to interdecadal time scales, but with different timing. Since 2000 warm SAT anomalies were found during most of the year in three of the four sub-arctic seas, with the exception of the Sea of Okhotsk. A seesaw (out of phase) pattern in winter SAT anomalies between the Labrador and the Barents Sea in the Atlantic sector is observed during the past 50 years before 2000; a similar type of co-variability between the Sea of Okhotsk and the Bering Sea shelf in the Pacific is only evident since 1970s. Recent positive anomalies of net heat flux are more prominent in winter and spring in the Pacific sectors, and in summer in the Atlantic sectors. There is a reduced magnitude in wind mixing in the Sea of Okhotsk since 1980, in the Barents Sea since 2000, and in early spring/late winter in the Bering Sea shelf since 1995. Reduced sea-ice areas are seen over three out of four (except the Sea of Okhotsk) sub-arctic seas in recent decades, particularly after 2000 based on combined in situ and satellite observations (HadISST). This analysis provides context for the pan-regional synthesis of the linkages between climate and marine ecosystems. 相似文献
15.
16.
The sea as a source of atmospheric phosphorus 总被引：1，自引：0，他引：1
The geochemical fractionation of phosphorus on the drop produced by bubbles bursting in seawater has been studied using a field sampling system called the Bubble Interfacial Microlayer Sampler (BIMS). The droplets from bursting bubbles were collected on filter samples in Narragansett Bay, Rhode Island during the summer of 1975. Phosphorus was found to be fractionated by the bubble-bursting process. The enrichment factor ranged from 4 to 170. Enrichment was found to increase with decreasing phosphorus concentration at 20 cm depth while it decreases with increasing wind velocity. Enrichment was independent of bubbling depth. Together these facts suggest that the sea-surface microlayer is the source of the phosphorus on the ejected drops. Organic phosphorus on the filter samples was found to be enriched relative to surface-water phosphorus by factors of 100–200, while reactive phosphorus was enriched by factors of only 6–8. This suggests that surface-active organic phosphorus compounds are the source phosphorus in the microlayer.The organic phosphorus content of samples of atmospheric particulates collected over the phosphate-rich upwelling waters near the Peru coast was found to correlate significantly with sea-salt sodium. Enrichments calculated using the average phosphorus concentration of the surface water in this area agree well with the results of the BIMS study. Thus it appears that phosphorus fractionation does occur in nature and may be important in supplying this nutrient to some coastal regions of the world. 相似文献
17.
18.
Abstract This paper gives the results of the density of diluted and concentrated standard seawater which has been measured in a salinity range from 0 to 42 and a temperature from 0 to 30°C. Equations for density of standard seawater (S = 35) vs the temperature and for density of standard seawater solutions vs the temperature and salinity have been fitted. 相似文献
19.
E. M. Dobryshman V. G. Kochina T. A. Letunova 《Izvestiya Atmospheric and Oceanic Physics》2013,49(5):494-503
Vortex simulation and the computation of fields of dynamic parameters of vortex structures (velocity, rotor velocity, and helicity) are carried out with the use of exact hydrodynamic equations in a cylindrical coordinate system. Components of centripetal and Coriolis accelerations are taken into account in the initial equations. Internal and external solutions are defined. Internal solutions ignore the disturbances of the pressure field, but they are considered in external solutions. The simulation is carried out so that the effect of accounting for spatial coordinates on the structure of the above fields is pronounced. It is shown that the initial kinetic energy of rotating motion transforms into the kinetic energy of radial and vertical velocity components in models with centripetal acceleration. In models with Coriolis acceleration, the Rossby effect is clearly pronounced. The method of an “inverse problem” is used for finding external solutions, i.e., reconstruction of the pressure field at specified velocity components. Computations have shown that tangential components mainly contribute to the velocity and helicity vortex moduli at the initial stage. 相似文献
20.
S. F. Dotsenko 《Physical Oceanography》1997,8(6):369-379
The paper addresses the plane linear problem on generation of an internal wave in a continuously stratified ocean by a moving
atmospheric front. The front exhibits air pressure perturbations, as well as the field of tangential wind stress. In the frame
of a model for the planetary atmospheric boundary layer, a relationship between the air pressure and wind fields has been
derived, generalizing Ackerbloom's formulae for the case of a moving atmospheric anomaly. Using the Fourier transform, a relation
has been obtained for the wave's signature in the wake of a moving atmospheric perturbation, and the respective analysis has
been performed. Numerical estimates of the internal wave amplitudes have been acquired for the mean density stratification
in the Kuril-Kamchatka region. Comparative analysis of the effectiveness of wave signature generation by the moving areas
of surface pressures and tangential wind stresses has been carried out. It has been demonstrated that the latter field determines
the effectiveness of baroclinic wave signature generation.
Translated by Vladimir A. Puchkin. 相似文献