The characteristics of daytime aurora at South Pole Station

Abstract

The characteristics of daytime auroras are examined by using all-sky camera photographs taken at South Pole Station in Antarctica. Several remarkable results were found from our analysis. (1) The auroral structure near the noon sector (10-14 MLT) mostly shows coronal forms with ray structure. (2) The luminostity of coronal form auroras is generally weaker than that of the midnight discrete auroras. However, their dynamical motion and their luminosity increase during the geomagnetic disturbed period. (3) Activity of daytime coronal auroras is dependent on the North-South component of Interplanetary Magnetic Field (IMF-Bz) variations. (4) The characteristics of morning sector auroras (06-10 MLT) are quite different from afternoon sector auroras (14-18 MLT). This tendency strongly suggests that there are asymetrical auroral phenomena between the morning and the afternoon regions.