The Negative Phase Ionospheric Disturbance and its Solar-terrestrial Correlation

This paper deals with the morphology of negative phase ionospheric disturbances. The ionospheric stations involved are Manzhouli (49°35, N, 117°27, E), Beijing (40°00, N, 116°18, B), Chongqing (29°30, N, 106°25, E), Guangzhou (23°09, N, 113°21, E) and Haikou (20°00, N, 110°20, E) for the period of 1965-1982, and also the correlation of the ionospheric disturbances with solar flares, solar radio emission, and geomagnetic field are analyzed. The solar and geomagnetic data are taken from the Solar-geophysical Data published by National Geophysical Data Center, Boulder, Colorado, USAand Report of Geomagnetic Observation by Beijing Geomagnetic Observatory.