A NEW MODEL OF QUASI-STATIONARY VORTICES

IN THE EARTH′S ATMOSPHERE

O.G. Onishchenko1, 2, O.A. Pokhotelov1, N.M. Astafieva2 

1Schmidt Institute of Physics of the Earth, Russian Academy of Sciences, Moscow, Russia

2 Space Research Institute, Russian Academy of Sciences, Moscow, Russia

Abstract. In a great variety of vortex motions in the atmosphere, concentrated vortices are clearly distinguished, attracting increased interest from the point of view of both fundamental research and practice. A sufficiently precise definition of the concentrated vortex can be given for the case of an ideal fluid – it is a localized area in space with a nonzero turbulence, surrounded by a potential flow. Such vortices can be combined into a class of small-scale concentrated vortices, including dust devils (DD), water vortices, fire vortices and larger-scale and more intense tornadoes. Unlike planetary-scale vortices (cyclones and anticyclones), DD and tornadoes are small-scale vortices. DD and tornadoes are generated in different environments (tornadoes occur in strong storm clouds), but have much in common in their structure. The speed of rotation in such vortices reaches the maximum value at a characteristic radius and tends to zero when approaching the center. The rotation speed in them has much in common with the rotation speed in the stationary Rankine or Burgers vortices.

     This paper is devoted to the study of a new low parametric model of stationary vortices most suitable for the description of concentrated vortices in the earth's atmosphere. Within the framework of ideal hydrodynamics, a new model of thin vortex filaments is constructed at altitudes small compared to the vertical scale of the earth's atmosphere. Unlike the Rankine and the Burgers vortices it allows to describe the structure limited in the radial direction. Quasi-stationary vortices in such a model arise as a result of the balance of two effects: the concentration of vertical vorticity to the center and the advection of the vortex motion in the vertical direction.

Keywords: vortices, a model of vortices, nonlinear structure, ideal hydrodynamics.

About the authors

ONISHCHENKO Oleg G. – Ph. D. (phys. and math.), chief researcher, Schmidt Institute of Physics of the Earth, Russian Academy of Sciences; chief researcher, Space Research Institute, Russian Academy of Sciences.  Moscow, Russia. Tel.: +7 (499) 254-88-05. E-mail: onish@ifz.ru

POKHOTELOV Oleg A. – Ph. D. (phys. and math.), professor, chief researcher, Schmidt Institute of Physics of the Earth, Russian Academy of Sciences. Moscow, Russia. Tel.: +7 (499) 254-88-05. E-mail: pokh@ifz.ru

ASTAFIEVA Natalia M. – Ph. D. (phys. and math.), leading researcher, Space Research Institute, Russian Academy of Sciences. Moscow, Russia. Tel.: +7 (495) 333-21-45. E-mail: ast@iki.rssi.ru