Accession Number : ADA130115

Title :   Magnetohydrodynamic Modelling of Interplanetary Disturbances between the Sun and Earth.

Descriptive Note : Environmental research papers,

Corporate Author : AIR FORCE GEOPHYSICS LAB HANSCOM AFB MA

Personal Author(s) : Dryer,M ; Wu,S T

PDF Url : ADA130115

Report Date : 21 Dec 1982

Pagination or Media Count : 50

Abstract : A time-dependent, nonplanar, two-dimensional (2-D) magnetohydrodynamic computer simulation model is used to simulate a series of solar flare-generated shock waves and their subsequent disturbances in interplanetary space between the sun and the earth's magnetosphere. The canonical or anzatz series of shock waves include initial velocities near the sun over the range 500 to 3000 km/sec. The ambient solar wind, through which the shocks propagate, is taken to be a steady-state flow that is independent of heliolongitude; its radial dependency consists of a representative set of plasma and magnetic field parameters which will be presented. Particular attention is directed to the MHD model's ability to address fundamental operational questions regarding the long-range forecasting of geomagnetic disturbances. These questions are: (1) will a disturbance (such as the present canonical series of solar flare shock waves) produce a magnetospheric and ionospheric disturbance, and, if so; (2) when wil it start; (3) how severe will it be; and (4) how long will it last? The model's output is used to compute various solar wind indices of current interest for this purpose. It is concluded that future work should be focused on a cohesive updating of, for example, daily measured solar parameters as input for the model whose output should be compared with spacecraft data for specific events. (Author)

Descriptors :   *SOLAR WIND, SOLAR FLARES, SHOCK WAVES, PROPAGATION, INTERPLANETARY SPACE, IONOSPHERIC DISTURBANCES, MAGNETIC STORMS, MATHEMATICAL MODELS, MAGNETOHYDRODYNAMICS, COMPUTERIZED SIMULATION

Subject Categories : Atmospheric Physics

Distribution Statement : APPROVED FOR PUBLIC RELEASE