A statistical study of midlatitude spread F at Wallops Island, Virginia

摘要

An ionosonde study using data from Wallops Island, Virginia (37.95°N, 284.53°E, 67.5° dip angle), over a full solar cycle from 1996 to 2006 has been conducted. A pattern recognition algorithm is used to analyze these ionograms in order to determine the statistics of midlatitude spread F. An ionogram displays spread F both horizontally and vertically, which are defined as range and frequency spread F, respectively. Range and frequency spreading can occur either simultaneously or separately. Seasonal and solar cycle variations have been studied using the data set; both are significant and are somewhat different for range and frequency spread F. Correlations of spread F duration with F 10.7, Kp, and AE are investigated. The results provide insights into causative sources for both types of midlatitude spread F.