Constraints on the Solar Internal Magnetic Field from a Buoyancy Driven Solar Dynamo

نویسندگان

  • DIBYENDU NANDY
  • D. NANDY
چکیده

We report here results from a dynamo model developed on the lines of the BabcockLeighton idea that the poloidal field is generated at the surface of the Sun from the decay of active regions. In this model magnetic buoyancy is handled with a realistic recipe – wherein toroidal flux is made to erupt from the overshoot layer wherever it exceeds a specified critical field Bc (105 G). The erupted toroidal field is then acted upon by the α-effect near the surface to give rise to the poloidal field. In this paper we study the effect of buoyancy on the dynamo generated magnetic fields. Specifically, we show that the mechanism of buoyant eruption and the subsequent depletion of the toroidal field inside the overshoot layer, is capable of constraining the magnitude and distribution of the magnetic field there. We also believe that a critical study of this mechanism may give us new information regarding the solar interior and end with an example, where we propose a method for estimating an upper limit of the difusivity within the overshoot layer.

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

From fibril to diffuse fields during dynamo saturation

The degree of intermittency of the magnetic field of a large-scale dynamo is considered. Based on simulations it is argued that there is a tendency for the field to become more diffuse and non-intermittent as the dynamo saturates. The simulations are idealized in that the turbulence is strongly helical and shear is strong, so the tendency for the field to become more diffuse is somewhat exagger...

متن کامل

Outstanding Issues in Solar Dynamo Theory

The magnetic activity of the Sun, as manifested in the sunspot cycle, originates deep within its convection zone through a dynamo mechanism which involves non-trivial interactions between the plasma and magnetic field in the solar interior. Recent advances in magnetohydrodynamic dynamo theory have led us closer towards a better understanding of the physics of the solar magnetic cycle. In conjun...

متن کامل

A Convection Zone Dynamo including the Effects of Magnetic Buoyancy and Downward Flows

A magnetic flux tube may be considered both as a separate body and as a confined field. As a field, it is affected both by the cyclonic convection (α-effect) and differential rotation (Ω-effect). As a body, the tube experiences not only a buoyant force, but also a dynamic pressure due to downflows above the tube. When these two dynamic effects are incorporated into the αΩ dynamo equations, we o...

متن کامل

Characteristics Of A Magnetic Buoyancy Driven Solar Dynamo Model

We have developed a hybrid model of the solar dynamo on the lines of the Babcock–Leighton idea that the poloidal field is generated at the surface of the Sun from the decay of active regions. In this model magnetic buoyancy is handled with a realistic recipe wherein toroidal flux is made to erupt from the overshoot layer wherever it exceeds a specified critical field (10 G). The erupted toroida...

متن کامل

Crisis-Induced intermittency due to Attractor-Widening in a Buoyancy-Driven Solar dynamo

In a recent paper [M. A. J. H. Ossendrijver, A&A 359, 364 (2000)] numerical simulations of a 2D mean–field model where shown to produce grand minima, typical of the long-term behavior of solar magnetic activity. The model consisted of dynamo that features an α effect based on the buoyancy instability of magnetic fluxtubes, which gives rise to the switching back and forth from grand minima to “r...

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2002