Behavior of sporadic Na layers on small time scale

• Published in: Journal of atmospheric and solar-terrestrial physics Vol. 71; no. 12; pp. 1374 - 1382
• Main Authors: Liu, Yingjie, Yi, Fan
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 01.08.2009; Elsevier
• Subjects: Earth, ocean, space; Exact sciences and technology; External geophysics; Lidar observation; Mesosphere; Physics of the ionosphere; Physics of the magnetosphere; Small time scale; Sporadic Na layers; Far East; Asia; China; Sporadic Na layers; Small time scale; Mesosphere; Lidar observation; advection; intensity; growth rates; time scales; winds; Radar observation; Lidar; Formation mechanism
• ISSN: 1364-6826; 1879-1824
• DOI: 10.1016/j.jastp.2009.06.013

Seventeen sporadic Na (Na s) layers were observed from ~150 h of the 8-s Na density profiles obtained by lidar measurements at Wuhan, China. Each of them consists of a sequence of small-timescale density enhancement bursts. The burst intensity ranges from 200 to 10,400 cm −3. The burst duration and interval vary between 16 and 112 s. The instantaneous growth and decay rates often have an order of 100 cm −3 s −1. This suggests that there exists a very rapid atom removal process corresponding to the dramatic burst density enhancement if the advection effect by large-scale wind could be ignored. These results provide a new clue for explaining the formation mechanism of sporadic metal layers.