講演情報
[PEM12-P12]Numerical investigation on occurrence rates of sporadic E layers in the summertime of East Asia
*安藤 慧1、齊藤 昭則2、品川 裕之3 (1.国立研究開発法人情報通信研究機構、2.京都大学 大学院理学研究科、3.九州大学 国際宇宙惑星環境研究センター)
キーワード：
電離圏、スポラディックE層、中緯度、シミュレーション
This study investigates in detail the causes of zonal/meridional variations in occurrence rates of sporadic E layers (EsORs) in the summertime East Asia, deriving EsORs from Es simulations. Especially at mid-latitudes, EsORs are considered to be controlled dominantly by vertical ion convergence (VIC) above 100 km. However, some observations reported that zonal/meridional EsOR variations existed in East Asia during the summertime, which have not been explained in light of VIC variations. In this study, we performed Es simulations for East Asia in June-August 2017 and derived EsORs from the simulation. The simulated EsORs succeed in reproducing similar local time and spatial variations to the previously observed ones. A diagnostic analysis of Es simulations shows that phase relationships between non-migrating diurnal tides and migrating diurnal/semi-diurnal tides are crucial for EsORs. Vertical ion convergence driven by non-migrating diurnal tides below 100 km can change Es behaviors at both low- and mid-latitudes.