Dependence of Hydromagnetic Energy Spectra on Interplanetary Parameters.

Ground-based magnetometer data, recorded at AT&T Bell Laboratories' stations located at low to mid-latitudes (L=2-4) and AFGL station (L=2-3), have been analyzed to search for associations between dayside Pc3-5 pulsations (15-240 second periods) and solar wind parameters measured by instrumentation on board the IMPJ spacecraft. The statistical analysis techniques used in the work (power spectral analysis, correlation analysis, multiple linear regression methods) have led to the discovery and quantification of relationships between hydromagnetic waves in the magnetosphere as manifested by magnetic pulsations and interplanetary parameters. Multiple linear regression (MLR) analyses showed that the most important interplanetary parameter controlling ground hourly magnetic energy (in the period range 60-240 seconds) was the solar wind speed. MLR analyses further showed that hourly magnetic energy in the 15-60 second period range was also controlled by the solar wind speed but more so by the interplanetary magnetic field direction.