Accession Number : ADA308299

Title :   Chaotic Dynamics of the Solar Cycle.

Descriptive Note : Final rept. 1 Nov 91-31 Oct 95,

Corporate Author : TRUSTEES OF COLUMBIA UNIV NEW YORK

Personal Author(s) : Spiegel, Edward A. ; Zahn, Jean-Paul

PDF Url : ADA308299

Report Date : 29 FEB 1996

Pagination or Media Count : 12

Abstract : The cyclic variation of solar activity is both irregular and intermittent. We have sought to isolate and illuminate the physical mechanisms of this behavior and to provide a mathematical description of it. Our work has brought out three ingredients of the solar cycle that we believe to be central to its operation. (1) The seat of the solar cycle is in a shear layer just below the solar convection zone. We have investigated the structure of this layer (which we call the solar tachocline) in some detail. (2) The spatio-temporal development of the solar cycle is represented by the propagation of robust solitary waves which are affected by dissipation and instability. We have studied the structure and interactions of such waves, which we call solitoids. (3) On top of the simple propagative behavior of the solar solitoids there are intermissions during which the number of sunspots remains quite small. We attribute these intermissions (such as the Maunder minimum) to a form of interaction between the convection zone and the tachocline which is characteristic of a process that we have developed and that we call on/off intermittency. These three ingredients make up some of the key features of the solar cycle and may be expected to play a role in future simulations of the solar cycle.

Descriptors :   *CHAOS, *SOLAR CYCLE, *SUNSPOTS, MATHEMATICAL MODELS, MAGNETIC FIELDS, SOLAR ENERGY, NONLINEAR ANALYSIS, ATMOSPHERE MODELS, MAGNETIC STORMS, CONVECTION(ATMOSPHERIC), PERIODIC VARIATIONS, SOLAR ATMOSPHERE.

Subject Categories : Astrophysics

Distribution Statement : APPROVED FOR PUBLIC RELEASE