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61.
We perform spectral analysis of records of meteorological (temperature, humidity, pressure of the atmosphere) and electrical (strength of quasi-static electric field and electric conductivity of air) parameters observed simultaneously at the Paratunka observatory during the solar events of October 21–31, 2003. Also, we use simultaneous records of X-ray fluxes of solar radiation, galactic cosmic rays, and the horizontal component of the geomagnetic field. We show that the power spectra of the meteorological parameters under fine weather conditions involve oscillations with a period of thermal tidal waves (T ~ 12 and 24 h) caused by the influx of thermal radiation of the Sun. During strong solar flares and geomagnetic storm of October 29–31 with a prevailing component of T ~ 24 h, their spectra involve an additional component of T ~ 48 h (the period of planetary-scale waves). With the development of solar and geomagnetic activities, the power spectra of atmospheric electric conductivity and electric field stress involve components of both thermal tidal and planetary-scale waves, which vary highly by intensity. In the power spectra of galactic cosmic rays accompanying the strong solar flares, components with T ~ 48 h were dominant with the appearance of additional (weaker by intensity) components with T ~ 24 h. The simultaneous amplification of components with T ~ 48 h in the power spectra of electric conductivity and electric field strength provides evidence of the fact that the lower troposphere is mainly ionized by galactic cosmic rays during strong solar flares and geomagnetic storms. The specified oscillation period with T ~ 48 h in their spectra, as well as in the spectra of X-ray radiation of the sun, is apparently caused by the dynamics of solar and geomagnetic activities with this time scale. 相似文献
62.
Specific processes of delta formation at the Mississippi River mouth are discussed. In the last 7000–8000 years, a series
of large deltaic lobes was formed in succession at the Mississippi River mouth under the condition of high river sediment
runoff and stabilization of the ocean level after its sudden postglacial rise. In the mid-XX century, the formation of a new
deltaic lobe began at the Atchafalaya Branch mouth. Over the last centuries, the processes of delta formation at the Mississippi
River mouth slowed down as a result of the river sediment runoff decrease after flow regulation of the Missouri and Arkansas
tributaries; in some parts of the deltaic plain, these processes gave way to degradation of marshes and seashore erosion under
the impact of intense land subsidence. The current processes of delta formation are under the great influence of local economic
activities. 相似文献
63.
M. V. Mikhailova 《Water Resources》2008,35(2):137-155
The main hydrological and morphological features of the Columbia River mouth area, including its tidal estuary, are discussed. Close attention is given to the characteristics of large-scale hydraulic projects in the river basin as well as to dredging and channel training operations in the river mouth area and to the assessment of the impact of these operations on hydrological and morphological processes. Variations in the regime of river flow after its regulation, processes of dynamic interaction and mixing of river and sea water in the estuary are characterized. Changes of the mouth bar and sea coasts near the Columbia River mouth as a result of construction of stream-training jetties are discussed. 相似文献
64.
Ivanov V. A. Lyubartseva S. P. Mikhailova É. N. Shapiro N. B. Shteinman B. S. 《Physical Oceanography》2002,12(1):43-53
Within the framework of a one-dimensional model taking into account the presence of an upper mixed layer, we compute the seasonal variation of temperature and the concentration of dissolved oxygen in the central part of Lake Kinneret. The temperature conditions of the lake are determined by heat exchange with the atmosphere, and the oxygen conditions depend on gas exchange with the atmosphere and oxygen consumption in sediments as well as on internal sources and sinks. The latter are connected with oxygen supply in the course of photosynthesis and its consumption for the oxidation of labile organic substance in the water thickness. In the period of winter convection from December to February, when the upper mixed layer reaches the bottom, complete aeration of water takes place. The presence of thermal stratification of the lake in the remaining time results in oxygen deficiency under the thermocline. 相似文献
65.
Through numerical modelling, the paper studies water circulation in the Gulf of Izmir. To this end, a multilevel model is
applied based on the primitive hydrodynamics equations. The calculations allow to describe the structure of circulation under
various wind conditions. Physical mechanisms are scrutinized, controlling water circulation in the Gulf of Izmir.
Translated by Vladimir A. Puchkin. 相似文献
66.
A. I. Androsovich V. A. Ivanov E. N. Mikhailova N. B. Shapiro 《Physical Oceanography》1997,8(2):81-91
A barotropic variant of a multilevel numerical model based on primitive equations of sea dynamics is applied to calculate
wind-induced circulation in the Donuzlav lake. Water exchange with the open sea is considered. The paper examines several
situations involving wind forcing. It shows that a two-layer system of currents occurs in the lake. The effect of the bottom
topography is essential, being traceable up to the surface.
Translated by Vladimir A. Puchkin. 相似文献
67.
A multilevel model based on primitive equations and a monotonic finite-difference scheme is applied to study the fluid dynamics over the north-western Black Sea shelf. Wind-generated currents and currents induced by river discharge are simulated in terms of the barotropic version. The effects of the bottom topography, the rigid-lid approximation, and the interaction of wind and river discharge-induced flows are examined.Translated by Vladimir A. Puchkin. 相似文献
68.
We discuss the results of the numerical experiment aimed at the simulation of the behavior of currents and transformations
of the temperature and salt modes in the Sevastopol Bay in January–February 1997. In the numerical analysis, we use actual
data on the velocity and direction of the wind, sea surface temperature, and the discharge of River Chernaya. It is shown
that the circulation and structure of hydrological fields are mainly connected with the direction of the wind, its intensity,
and variability in the course of time. Since the analyzed water area is shallow, the currents inside the bay undergo rapid
transformations (less than for an hour after changes in the wind). At the same time, the transformations of the thermohaline
fields are slower. Due to the inflow of fresh waters of River Chernaya and salt waters from the open sea through the strait,
the structure of thermohaline fields formed in the bay is nonuniform (both in the vertical and horizontal directions). The
distribution of salinity plays the main role in the formation of the vertical stratification, which is natural for the winter
season. Due to the process of freshening of water, a quite high vertical salinity gradient is formed in the upper layer of
the sea. As a result, the process of cooling does not lead to the appearance of convection and inversions of temperature are
formed in the case where warmer waters are located in the bottom layers.
__________
Translated from Morskoi Gidrofizicheskii Zhurnal, No. 2, pp. 60–76, March–April, 2005. 相似文献
69.
The article investigates parametrization issues of the main shock from the earthquake of June 13, 2009, m b = 6.3 felt in Tekeli town with intensity 7. Spatial characteristics of the source, mechanism and CMT, aftershock activity regularities were studied. Rupture plane in the source was defined with high probability. Information and pictures about destructions and damages of buildings on the territory of Tekeli town as well as isoseismal map are shown. In 1993 almost at the same place the earthquake with the same focal parameters and processes occurred. Very close parameters of seismic effects on the territory of Almaty having two almost the same sources were noted. 相似文献
70.