Dayside Auroral Activity During Solar Maximum and Minimum Periods
Gerard J Fasel1, Julia Flicker2, Megan Rawie2, Alexandra Angelo2, Sarah Bender2, Mashaer Alyami2, David G Sibeck3, Fred Sigernes4, Dag A Lorentzen5 and David Green2, (1)Pepperdine University, Natural Science, Malibu, CA, United States, (2)Pepperdine University, Malibu, CA, United States, (3)NASA/GSFC, Greenbelt, United States, (4)University Centre in Svalbard, Longyearbyen, Norway, (5)UNIS, Longyearbyen, Norway
Abstract:
It is well documented that the dayside auroral oval shifts equatorward when the interplanetary magnetic field (IMF) B
z-component turns southward [Burch, 1973; Akasofu, 1977; Horwitz and Akasofu, 1977; Sandholt et al., 1986, 1988]. During these periods of oval expansion dayside transients are observed to move away from the poleward edge of the auroral oval and drift poleward. These poleward-moving auroral forms are believed to be ionospheric signatures of dayside merging. The dayside auroral oval usually begins to contract when the interplanetary magnetic field turns sharply northward, B
z>0.
Eighteen years of meridian scanning photometer (MSP) data from the Kjell Henriksen Observatory in Longyearbyen, Norway are analyzed. During the boreal winter the Sun is several degrees below the horizon. This permits optical observations throughout the daytime period. The MSP Data is selected two hours before and after local noon in Longyearbeyn. Solar wind data (solar wind pressure and speed, along with the IMF Bx, By, Bz components) are collected for each interval and combined with the MSP observations. This data is then separated using solar maximum and minimum periods. Auroral activity (oval expansions and contractions along with the frequency and number of poleward-moving auroral forms) is documented for both solar maximum and minimum periods.
