A study of local time and longitudinal variability of the amplitude of the equatorial electrojet observed in POGO satellite data

The local time and longitudinal variations of the amplitude of the equatorial electrojet (EE) are investigated using the POGO series satellite data. An iterative normalization scheme is developed to separate the variations of the amplitude of the EE with respect to longitude and local time. The resulting local time variation of the EE compares favorably with observatory based studies; however, the longitudinal variation is not well resolved. The altitude of the satellite is another factor that affects the amplitude of the EE. We use a simple linear scaling of amplitude of the EE with the inverse of the satellite altitude. An experiment including only the satellite passes below 450 km altitude indicates that there may be problems in correcting the data from higher altitudes. The reason behind the discrepancy between the results from the data limited to below 450 km and the full data set is not understood and requires further investigation.