Conditions

H

$2\pi /k_g$

Sound speed

$c_g$

$2\pi /{\omega }_g$

$V_{gz\max }$

altitude 0 - 150 km

7 km

100 km

300 m/s

270 m/s

5.5 min

50 m/s

altitude > 150 km

high solar activity

50 km

700 km

890 m/s

870 m/s

12 min

170 m/s

altitude > 150 km

low solar activity

30 km

420 km

720 m/s

700 m/s

10 min

135 m/s