Convective column above a linear fire in a polytropic atmosphere

1978 ◽  
Vol 14 (3) ◽  
pp. 271-275 ◽  
Author(s):  
Yu. A. Gostintsev ◽  
L. A. Sukhanov
Keyword(s):  
Convective Column ◽  
Polytropic Atmosphere

scholarly journals Oscillatory convection in strong magnetic fields and origin of active regions

1968 ◽  
Vol 35 ◽  
pp. 127-130 ◽  
Author(s):  
S. I. Syrovatsky ◽  
Y. D. Zhugzhda
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Active Regions ◽  
Oscillatory Convection ◽  
Strong Magnetic Fields ◽  
Various Boundary Conditions ◽  
Convective Cells ◽  
The Magnetic Field ◽  
Polytropic Atmosphere

The convection in a compressible inhomogeneous conducting fluid in the presence of a vertical uniform magnetic field has been studied. It is shown that a new mode of oscillatory convection occurs, which exists in arbitrarily strong magnetic fields. The convective cells are stretched along the magnetic field, their horizontal dimensions are determined by radiative cooling. Criteria for convective instability in a polytropic atmosphere are obtained for various boundary conditions in the case when the Alfvén velocity is higher compared with the velocity of sound.The role of oscillatory convection in the origin of sunspots and active regions is discussed.

On vortex air motions above an axisymmetric source of mass, momentum and heat

1995 ◽  
Vol 290 ◽  
pp. 299-317
Author(s):  
Y. A. Berezin ◽  
K. Hutter
Keyword(s):  
Large Scale ◽  
Nonlinear Differential Equations ◽  
Azimuthal Velocity ◽  
Small Scale ◽  
Ambient Atmosphere ◽  
Plume Dispersion ◽  
Governing Equations ◽  
Balance Equations ◽  
Velocity Pressure ◽  
Polytropic Atmosphere

We study axisymmetric plume dispersion from a steady source of mass, momentum and/or heat that is subjected to either a time-dependent large-scale external vortex or small-scale turbulent axisymmetric helicity. On the basis of the turbulent boundary layer and Boussinesq assumptions and by assuming similarity profiles with Gaussian distribution in the radial direction the balance equations of mass, momentum, and energy reduce to a system of nonlinear differential equations for amplitude functions of axial velocity, pressure and density differences as well as azimuthal velocity. The system of equations is closed with Taylor's entrainment assumption.The plume radius and the typical radius of the large-scale external vortex are also determined. For a simple density structure of the ambient atmosphere (i.e. adiabatic conditions) analytical results can be obtained, but for more complicated cases, i.e. a layered polytropic atmosphere, the governing equations are examined numerically; computations are reasonably simple and efficient.

scholarly journals Thermo-convection in a polytropic atmosphere.

1955 ◽  
Vol 60 ◽  
pp. 179
Author(s):  
Andrew Skumanich
Keyword(s):  
Polytropic Atmosphere

scholarly journals Nonlinear instability of baroclinic atmosphere with reference to planetary scale disturbances

2004 ◽  
Vol 11 (3) ◽  
pp. 363-370
Author(s):  
I. A. Pisnichenko
Keyword(s):  
Zonal Wind ◽  
Sufficient Conditions ◽  
Zonal Flow ◽  
Vertical Gradient ◽  
Finite Amplitude ◽  
Lapse Rate ◽  
Temperature Lapse Rate ◽  
Planetary Scale ◽  
Conditions Of Stability ◽  
Polytropic Atmosphere

Abstract. In this paper we investigate the stability of zonal flow in a baroclinic atmosphere with respect to finite-amplitude planetary-scale disturbances by applying Arnold's method. Specifically, we examine the sign of the second variation of a conserved functional for the case of a polytropic atmosphere (i.e. one with a linear lapse rate) and with a linear profile of zonal wind. Sufficient stability conditions for an infinite atmosphere (i.e. with a temperature lapse rate equal to zero) are satisfied only for an atmosphere in solid body rotation. For a polytropic atmosphere of finite extent (a lapse rate is not equal zero) the sufficient conditions of stability can be satisfied if a lid is placed below min (Zmax, polytropic atmospheric height). The dependence of height Zmax on values of the vertical gradient of the zonal wind and the zonal temperature distribution is calculated.

scholarly journals Modelling the chemistry and transport of bromoform within a sea breeze driven convective system during the SHIVA Campaign

2013 ◽  
Vol 13 (8) ◽  
pp. 20611-20676 ◽  
Author(s):  
P. D. Hamer ◽  
V. Marécal ◽  
R. Hossaini ◽  
M. Pirre ◽  
N. Warwick ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Climate Models ◽  
Stratospheric Ozone ◽  
Sea Breeze ◽  
Convective System ◽  
North West ◽  
Mixing Ratios ◽  
The North ◽  
Relative Contribution ◽  
Convective Column

Abstract. We carry out a case study of the transport and chemistry of bromoform and its product gases (PGs) in a sea breeze driven convective episode on 19 November 2011 along the North West coast of Borneo during the "Stratospheric ozone: Halogen Impacts in a Varying Atmosphere" (SHIVA) campaign. We use ground based, ship, aircraft and balloon sonde observations made during the campaign, and a 3-D regional online transport and chemistry model capable of resolving clouds and convection explicitly that includes detailed bromine chemistry. The model simulates the temperature, wind speed, wind direction fairly well for the most part, and adequately captures the convection location, timing, and intensity. The simulated transport of bromoform from the boundary layer up to 12 km compares well to aircraft observations to support our conclusions. The model makes several predictions regarding bromine transport from the boundary layer to the level of convective detrainment (11 to 12 km). First, the majority of bromine undergoes this transport as bromoform. Second, insoluble organic bromine carbonyl species are transported to between 11 and 12 km, but only form a small proportion of the transported bromine. Third, soluble bromine species, which include bromine organic peroxides, hydrobromic acid (HBr), and hypobromous acid (HOBr), are washed out efficiently within the core of the convective column. Fourth, insoluble inorganic bromine species (principally Br2) are not washed out of the convective column, but are also not transported to the altitude of detrainment in large quantities. We expect that Br2 will make a larger relative contribution to the total vertical transport of bromine atoms in scenarios with higher CHBr3 mixing ratios in the boundary layer, which have been observed in other regions. Finally, given the highly detailed description of the chemistry, transport and washout of bromine compounds within our simulations, we make a series of recommendations about the physical and chemical processes that should be represented in 3-D chemical transport models (CTMs) and chemistry climate models (CCMs), which are the primary theoretical means of estimating the contribution made by CHBr3 and other very short-lived substances (VSLS) to the stratospheric bromine budget.

Overstabilization of acoustic modes in a polytropic atmosphere

Solar Physics ◽  
1978 ◽  
Vol 56 (2) ◽  
Author(s):  
H.M. Antia ◽  
S.M. Chitre ◽  
D.M. Kale
Keyword(s):  
Acoustic Modes ◽  
Polytropic Atmosphere
Sign in / Sign up

Export Citation Format

Share Document