The regional characteristics of couplings between ionosphere and lower atmosphere through gravity waves

1
The regional characteristics of couplings between
ionosphere and lower atmosphere through gravity
waves

• Prof. Z. Xiao
• Department of Geophysics
• Peking University
• Beijing, 100871
• China

2
For discussions

• We have evidences of the responses of the
  ionosphere to typhoons. The response does show
  certain special common features
• Two stations in China (Changchun and Wulumuqi)
  with the same latitude but about 40 degree
  difference in longitude showed very different
  occurrence frequencies of spread-F. Changchun is
  near the east coast of the Country while wulumuqi
  deep in the Chinese mainland. the occurrence of
  spread-F seems to be influenced by surface
  meteorology factors (waves in the lower
  atmosphere as seeds and others?)
• It seems that gravity waves in the lower
  atmosphere not only cause the TIDs in the
  ionosphere (this is well known), but also
  influence the morphological features of
  ionosphere so the ionosphere should have certain
  regional characteristcs

3
Left-upper record of ionosphere Doppler shift
during a typhoon. The typhoon landed on mainland
around 16h(LT). Notice the period evolution and
spread-F during the nightleft-lower another
typhoon which were near the mainland and became
strongest around the night of 21st and not far
from the mainland right-lower comparison of the
occurrence of spread-F at Changchun and Wulumuqi
for all seasons. Noticd that spread-F occurred
much more frequent at Changchun