Showing papers on "Space weather published in 1985"

Solar wind-magnetosphere coupling

Abstract: An AGU Chapman Conference on Solar Wind-Magnetosphere Coupling was held at the Jet Propulsion Laboratory (JPL) of the California Institute of Technology, Pasadena, February 12–15, 1985. There were 95 scientific papers presented at the meeting, and 135 participants were registered. The interaction between the solar wind and the earth's magnetic field creates a large magnetic cavity that is termed the magnetosphere. Energy derived from the solar wind and subsequently transferred to the inner magnetosphere is the primary source of various dynamic processes in the magnetosphere and also of many interesting phenomena observable from the earth's surface, such as magnetic and auroral substorms. The purpose of this conference was to bring together scientists from all areas of solar terrestrial physics, both theoretical and experimental, to promote the study of “coupling” among the different regions of the geosphere.

The solar/interplanetary/magnetosphere/ionosphere connection - A strategy for prediction of geomagnetic storms

Abstract: A physically-based strategy for the prediction of geomagnetic/ionospheric disturbances, the Solar-Terrestrial/Environmental Model (STEM 2000), is proposed, with application to the prediction of periods of spacecraft charging. Synoptic solar observations provide input for MHD models for flare occurrence, propagation of coronal disturbances, and high speed solar wind streams. A three-dimensional interplanetary MHD model determines solar wind parameters including the energy flux and the cross-magnetosphere tail electric field. Observational earth data are used to predict local time, high latitude ionospheric disturbances which have an impact on the ionospheric structure.

Use of Interplanetary Scintillation for Earth Space Environment and Geomagnetic Forecasting.

Abstract: : A comparison is presented between solar wind velocities determined from IPS (Interplanetary Scintillation) observations made from 1973 to 1981 with those measured in situ by spacecraft instruments. The IPS method is indirect but it provides reasonably accurate estimates of the large scale and slowly varying velocity structures in the solar wind. Thus the corotating solar wind streams typical of 1973-75 (declining and low solar activity) are well estimated; the slower average speed typical of 1979-81 was also well estimated. However, the transient increases during this period of high solar activity were often not detected. The difficulties of interpretation are offset by the capacity to monitor the solar wind speed out of the ecliptic and over long periods of the time without the expense of a spacecraft. Keywords: Interplanetary space.

Study of Dominating Parameters of High Speed Solar Plasma Streams in Relation to Cosmic Ray and Geomagnetic Storms

Abstract: The high speed solar wind streams observed near Earth are generally associated with the solar features, such as solar flares and coronal holes. Past studies of these streams from the two sources have revealed distinctly different effects on cosmic ray intensity, whereas the effect is similar for geomagnetic disturbances. Moreover, the effect of the magnitude of the high speed streams (V) and its rate of increase (dv/dt) has also been a subject of investigation to understand their relative contribution in producing geomagnetic disturbances. From the analysis of some of the fast streams presented here, it is difficult to predict, which one of the two (V, dv/dt) is more effective in producing geo-magnetic disturbances. Further, in most of the cases, no substantial decrease in cosmic ray intensity is observed.