Understanding of the sources of the F-region field-aligned irregularities in the middle latitude using ground-based and satellite observations

The electron density irregularities in the F region are problematic in satellite communication and navigation systems. Extensive efforts have been made to understand the onset conditions and sources of such irregularities and to predict or avoid the impact of these irregularities on the society. A VHF radar was built at Daejeon (36.2°N, 127.1°E, 26.7°N dip latitude) in South Korea in December 2009 to study the characteristics and source of the irregularities in middle latitudes. Our study investigates the occurrence climatology of the field-aligned irregularities (FAIs) and their association with medium-scale traveling ionospheric disturbances (MSTIDs) and sporadic E. The activity of FAIs is investigated with the Daejeon radar data acquired in 2010-2016, and the occurrences of MSTIDs and sporadic E are monitored with the total electron content maps over Japan and ionosonde data at Icheon in South Korea, respectively. Swarm satellite observations are used to investigate the field-aligned properties in the F-region FAIs. Through the comparison of the activities of F-region FAIs, MSTIDs, and sporadic E, we assess the role of MSTIDs and sporadic E in the creation of the F-region FAIs.