9:00 AM - 9:15 AM
[PEM15-01] Dawn-Dusk Asymmetry in Dayside auroral Ovals: Surveys of dayside auroral emission and morphology in Arctic and Antarctica
Keywords:dawn-dusk asymmetry, dayside aurora
Based on the morphological characteristics of the four labeled dayside discrete auroral types (include auroral arc, drapery corona, radial corona and hot-spot aurora) on the 8001 dayside auroral images at Yellow River Station in 2003, and by extracting the local binary pattern (LBP) features and using k-nearest classifier, we make an automatic classification to the 65361 auroral images of the Yellow River Station during 2004-2009 and the 39335 auroral images of the South Pole Station between 2003-2005, and finally obtains the occurrence distribution of the dayside auroral morphology in northern and southern hemispheres. The statistical results indicate that the four dayside discrete auroral types present similar occurrence distribution between the two stations: 1) The occurrence distributions of arc auroras show a distinct dawn-dusk asymmetry with a postnoon peak; 2) The drapery corona auroras also show a dawn-dusk asymmetry, but the peak is on the prenoon; 3) The occurrence peak of radial corona is in the midday; 4) The hot-spot auroras most occur in region 1300-1530 MLT and have a distinct small peak around 1330MLT. These distribution characteristics of dayside auroras are related with the distributions of dynamic processes in the magnetopause/magnetospheric boundary layer.