Characteristics of the Afternoon E-region Plasma Density Irregularities in Middle Latitudes

Monday, 15 December 2014
Young-Sil Kwak1, Tae-yong Yang1, Hyosub Kil2 and Yuichi Otsuka3, (1)KASI Korea Astronomy and Space Science Institute, Daejeon, South Korea, (2)Johns Hopkins University, Baltimore, MD, United States, (3)Nagoya Univ, Nagoya, Japan
In middle latitudes, radar probing of E-region ionospheric electron density irregularities has been carried out for several decades. However, no the afternoon (i.e., from noon to pre-sunset time) E-region field-aligned irregularities (FAIs) in middle latitude have been reported yet. On the other hand, a 40.8 MHz VHF radar operated continuously since December 2009 at Daejeon (36.18°N, 127.14°E, 26.7°N dip latitude) in South Korea has often observed the E-region FAIs in the afternoon. In this presentation, therefore, we report firstly the afternoon observations of the mid-latitude E-region FAIs made by the Daejeon radar. We present the characteristics and statistical morphology of the mid-latitude afternoon E-region FAIs based on the continuous and long-term radar observations. And also, to investigate the afternoon E-region FAIs – Sporadic E (Es) relationship, the FAIs have been also compared with Es parameters based on observations made from an ionosonde located at Icheon (37.14°N, 127.54°E, 27.7°N dip latitude), which is 100 km north of Daejeon.