Altitude development of postmidnight F region field-aligned irregularities observed using Equatorial Atmosphere Radar in Indonesia

作者：Tam Dao^*; Otsuka Yuichi; Shiokawa Kazuo; Ram S Tulasi; Yamamoto Mamoru

来源：Geophysical Research Letters, 2016, 43(3): 1015-1022.

DOI：10.1002/2015GL067432

• F region field-aligned irregularity
• equatorial ionosphere
• Equatorial Atmosphere Radar
• rise velocities of FAIs
• plasma bubbles
• spread F

For the first time, vertical rise velocities of postmidnight field-aligned irregularities (FAIs) at low geomagnetic latitudes have been examined near the June solstice by using two-dimensional maps of F region FAI echoes observed with the Equatorial Atmosphere Radar in Indonesia for 3years starting in May 2010. We found 15 freshly growing FAIs at postmidnight between May and August during the 3years. The rise velocities of FAIs are smaller at postmidnight than at postsunset, and most postmidnight FAIs do not exceed an altitude of 450km. Based on the rise velocities, a lower limit for the creation time of the postmidnight FAIs is estimated to be between 21:30LT and 02:00LT for 14 of the 15 events, indicating that this class of FAIs is distinct from the postsunset FAIs.

• 出版日期2016-2-16