Pulsation signatures on SANAE magnetometers

• Main Author: Potucek, Michael
• Format: Others
• Language: English
• Published: KTH, Rymd- och plasmafysik 2007
• Online Access: http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-91826

The newest station in the South African National Antarctic Expedition, the SANAE IV, hostsnumerous research programmes. One is AMIGO which aims to establish the correlationbetween the solar wind and the magnetosphere. A magnetometer, located at a geographicposition of2.83°W, 71.67°S, consisting of two perpendicular coil sensors is installed to detectgeomagnetic field motions, also known as pulsations, in the North-South and East-Westdirections. ([7])The data, treated in this report, cover the years 2003 and 2004 with the exception of the 20first days in January 2003 and another randomly scattered 22 dates during both 2003 and2004 when the data are corrupt or simply just nonexistent.The data consist of detected pulses that are recorded as a voltage, unit m V, which aretransformed into corresponding magnetic flux density amplitudes. The interesting pulsationfrequencies are extracted from the respective powerspectra for certain time intervals. Toconduct this operation a MA TLAB-program that extracts these frequencies is later used toproduce statistics to provide a graspable view of the frequency distribution.The statistics show that the pulsations within the Pc4 range, and specifically the ones close toPc5, are most represented in the data, closely followed by the Pc5 and with a small but yetsignificant representation of frequencies from the Pc3 range. Pc 1 and Pc2 frequencies aredetected sporadically but their existence is negligible at the whole.It is also established that the daytime pulsations are scattered over a wider frequency spectrumthan during evening or morning, with the widest spectrum somewhere around noon ± 2 hours.Some of the results are in acceptable correlation with the theoretical assumptions such aswhere and when the different sources set up the pulsations.