Coherent Structures in the Atmospheric Surface Layer under Stable and Unstable Conditions

Koprov, B. M.; Koprov, V. M.; Makarova, T. I.; Golitsyn, G. S.

doi:10.1023/b:boun.0000010996.99753.d3

Cited by 13 publications

(4 citation statements)

References 11 publications

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“…The method is based on the algorithm of detecting coherent structures in the field of the studied random process [14,15]. Modification of the method consists in that a synchronous signal from the temperature sensors is assumed equal to unity simultaneously for all the thermosensors of the measuring line if the temperature exceeds a certain threshold quantity equal toT (r i ) + aσ T (r i ).…”

Section: Observation Results and Discussionmentioning

confidence: 99%

“…On the other hand, synchronous multipoint measurements of the altitude profile of the temperature made it possible to obtain new data on the spatial structure of temperature inhomogeneities of the atmospheric surface layer. Based on the analysis of temporal correlation functions of the temperature, temperature convective structures with spatial scales and inter-structure distances related to the thickness of the atmospheric surface layer were found [14,15].…”

Section: Introductionmentioning

confidence: 99%

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Mechanisms of coupling of aeroelectric and temperature fields in the lower atmosphere

Anisimov

Mareev

Shikhova

2006

Radiophys Quantum Electron

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at the measuring facility of the mid-latitude geophysical observatory "Borok" (Yaroslavsl' Region, Russia), we conclude that correlative relations exist between the aeroelectric-field intensity E and the air temperature T in the atmospheric surface layer. We reveal positive correlation between the temperature and electric-field variations under conditions of unstable stratification (late morning-day) and negative correlation under stable stratification (late evening-night). A simultaneous increase in the amplitude of pulsations of the electric field and the temperature occurs most frequently near the local midday. Intense variations in the electric field correspond to variations in the temperature field with a close time period. A positive temporal shift of variations in E with respect to variations in T , which reaches 40 min, is observed during enhanced temperature activity. The structure-temporal analysis of experimental data from remote sensing of the temperature and electric-field variations at five points is performed. We find simultaneous aeroelectric and temperature coherent structures accompanied by short-period pulsations of the field intensity and the air temperature in the atmospheric surface layer.We discuss possible mechanisms of coupling of the aeroelectric-field intensity and the atmospheric air temperature to describe their positive correlation under conditions of unstable stratification (late morning-day) and negative correlation in the late evening and at night. Enhancement of electric activity, which is stipulated by the intensification of turbulent convection and the formation of aeroelectric structures, seems the most significant process. With allowance for nonlocality of the electric field, this process can in particular explain a substantial lead of the aeroelectric-field perturbations compared with the correlated positive temperature perturbations. In this case, the formation of warm "quasi-front," which is accompanied by the lifting of the nearsurface air abundant in moisture and charged particles to the higher atmospheric layers, can play an important role. Other mechanisms of the field-temperature coupling take into account a decrease in the conductivity of near-surface air due to the condensation of water vapor during its cooling, as well as an increase in the mobility of light ions with increasing air temperature.

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Section: Observation Results and Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Mechanisms of coupling of aeroelectric and temperature fields in the lower atmosphere

Anisimov

Mareev

Shikhova

2006

Radiophys Quantum Electron

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“…The mechanisms of the origin of the initial field of mesovortices can be different: the formation of coherent structures of a 50-500 m scale in the surface layer of the atmosphere [65]; vortices in floating turbulent jets caused by both natural and anthropogenic factors [66]; anomalies of the average monthly temperature [67]; and, of course, the destruction of global vortices, for example, tropical cyclones [68].…”

Section: Thermodynamic Modelsmentioning

confidence: 99%

Mathematical Modeling of Structure and Dynamics of Concentrated Tornado-like Vortices: A Review

Varaksin

Ryzhkov

2023

Mathematics

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Mathematical modeling is the most important tool for constructing the theory of concentrated tornado-like vortices. A review and analysis of computational and theoretical works devoted to the study of the generation and dynamics of air tornado-like vortices has been conducted. Models with various levels of complexity are considered: a simple analytical model based on the Bernoulli equation, an analytical model based on the vorticity equation, a new class of analytical solutions of the Navier–Stokes equations for a wide class of vortex flows, and thermodynamic models. The approaches developed to date for the numerical simulation of tornado-like vortices are described and analyzed. Considerable attention is paid to developed approaches that take into account the two-phase nature of tornadoes. The final part is devoted to the analysis of modern ideas about the tornado, concerning its structure and dynamics (up to the breakup) and the conditions for its occurrence (tornadogenesis). Mathematical modeling data are necessary for interpreting the available field measurements while also serving as the basis for planning the physical modeling of tornado-like vortices in the laboratory.

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“…наряду с организованными крупномасштабными структурами, в пограничном слое постоянно существуют вихревые структуры меньшего, как пространственного -от десятков до сотен метров, так и временного масштабов -десятки секунд-минуты, ориентированные примерно на 30 градусов относительно направления геострофического ветра [1][2][3][4][5][6][7][8][9][10]. несмотря на давнюю регистрацию в численных моделях [11] и достаточно уверенную и детальную экспериментальную регистрацию [8], условия и механизмы генерации и поддержания таких структур остаются не до конца проясненными.…”

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On the algebraic perturbations in atmospheric boundary layer

Chkhetiani

Vazaeva

2019

Известия Российской академии наук. Физика атмосферы и океана

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A simple model for the development of submesoscale perturbations in the atmospheric boundary layer (ABL) is proposed. The growth of perturbations is associated with the shear algebraic instability of the wind velocity profile in the atmospheric boundary layer (ABL). For the scales of optimal perturbations (streaks) in the lower part of the ABL, estimates of their sizes were obtained about 100-200 m vertically and 300-600 m horizontally. Similar scales are noted for experimental data on the structure of the wind field in the lower part of the ABL, obtained in 2017, 2018 in the summer at the Tsimlyansk Scientific Station at the acoustic sounding of the atmosphere by the Doppler three-component minisodar of high resolution.

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Coherent Structures in the Atmospheric Surface Layer under Stable and Unstable Conditions

Cited by 13 publications

References 11 publications

Mechanisms of coupling of aeroelectric and temperature fields in the lower atmosphere

Mechanisms of coupling of aeroelectric and temperature fields in the lower atmosphere

Mathematical Modeling of Structure and Dynamics of Concentrated Tornado-like Vortices: A Review

On the algebraic perturbations in atmospheric boundary layer

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