Statistical Characteristics of the Local Proton Cyclotron Band Emissions Observed by the CSES

Abstract

AbstractWe present observations on the local proton cyclotron band emissions (PCBEs), which is one type of hiss wave in the upper ionosphere, recorded by the China Seismo‐Electromagnetic Satellite (CSES). The PCBEs are characterized by narrow‐band electromagnetic emissions along the local proton cyclotron frequency (), exhibiting a sharp cutoff effect. The lower cutoff frequency () is closely along the local , decreasing with magnetic latitude, while the upper cutoff frequency () is diffuse and deviates from the local . We developed an algorithm to automatically extract PCBEs from CSES's massive electromagnetic data and statistically examined their occurrence and bandwidth's dependence on location and season. The global morphology of PCBEs in 2019 shows that they primarily occur in the mid‐high magnetic latitude (approximately 20°–55°) dayside ionosphere, with the maximum occurrence happening around the South Atlantic Anomaly region. Their bandwidth shows a decreasing tendency with magnetic latitude and strong seasonal dependence, with a wider bandwidth in local winter and a narrower one in local summer. The ratio of and also shows a seasonal dependence, with greater values in local summer and smaller values in local winter. This characteristic of is similar to that of the H+‐He+ cutoff frequency (). This study provides statistical characteristics of occurrence and the cutoff features of PCBEs based on the CSES operating in the upper ionosphere.