scostep 2010 (stp12) - Leibniz-Institut für Atmosphärenphysik an der ...
scostep 2010 (stp12) - Leibniz-Institut für Atmosphärenphysik an der ...
scostep 2010 (stp12) - Leibniz-Institut für Atmosphärenphysik an der ...
Create successful ePaper yourself
Turn your PDF publications into a flip-book with our unique Google optimized e-Paper software.
STP12 Abstracts<br />
Berlin, 12 - 16 July <strong>2010</strong><br />
SCOSTEP Symposium <strong>2010</strong><br />
Geomagnetic <strong>an</strong>d ionospheric response to vertical acoustic reson<strong>an</strong>ce caused by lower<br />
atmospheric disturb<strong>an</strong>ces<br />
Iyemori Toshihiko 1 , Matsumura Mitsuru 1 , H<strong>an</strong> De-Sheng 2 , Nose Masahito 1 , Tomizawa Ichiro 3 ,<br />
Chiba Ryo 3 , T<strong>an</strong>aka Yoshikazu 4 , K<strong>an</strong>da Wataru 5 , Shinagawa Hiroyuki 6 , S<strong>an</strong>o Yasuharu 7 , Odagi<br />
Yoko 1 , Oshim<strong>an</strong> Naoto 8 , Utsugi Mitsuru 1 , Toh Hiroaki 1 , Iguchi Masato 8<br />
1 Graduate School of Science, Kyoto Univ., 2 Polar Research <strong>Institut</strong>e of China, 3 SSRO, U.<br />
Electro-Communications, 4 Setsun<strong>an</strong> Univ., 5 Volc<strong>an</strong>ic Fluid Research Center, Tokyo <strong>Institut</strong>e of<br />
Technology, 6 NICT, 7 Asahi Univ., 8 DPRI, Kyoto Univ.<br />
A large scale disturb<strong>an</strong>ce with short time scale in the lower atmosphere may generate acoustic<br />
waves, <strong>an</strong>d they propagate not only in a horizontal direction but also to the upper atmosphere.<br />
Because of exponential decrease of atmospheric mass density with height, a small pressure<br />
variation in the lower atmosphere is amplified to appreciable vertical wind at the ionospheric<br />
height, <strong>an</strong>d the vertical wind may cause electric currents or Alfvenic fluctuations in the<br />
ionosphere through dynamo process. The geomagnetic variation generated by the ionospheric<br />
current could be detected on the ground. As the source of lower atmospheric disturb<strong>an</strong>ces<br />
with large horizontal scale, large earthquakes, strong volc<strong>an</strong>ic eruptions, typhoons, total<br />
eclipses etc. are expected. The amplitude of the magnetic effects on the ground is in general<br />
very small <strong>an</strong>d difficult to distinguish from external (i.e., magnetospheric) effects. However,<br />
if we limit to the cases of the vertical reson<strong>an</strong>ce of the acoustic waves between ground <strong>an</strong>d<br />
ionosphere, it is possible to find the cases because of the theoretically expected reson<strong>an</strong>ce<br />
frequency. In this paper, we summarize the cases where the magnetic <strong>an</strong>d pressure variations<br />
with the acoustic wave reson<strong>an</strong>ce frequencies are detected <strong>an</strong>d discuss their characteristics.
Change language