Signature of Planetary Waves in the Thermosphere/Ionosphere System

本文研究了热层/电离层系统对中性大气行星波的响应。PW在130 km以上不传播。尽管如此，PW周期和波数的振荡（行星波型振荡，PWTO）在TIS中被记录。因此，间接过程必须负责向上输送PW能量。文献中提出了不同的可能性，例如重力波（GW）和潮汐的PW调制和电离层电射流的调制。在本项目中，将考虑GW调制。本提案所述的工作包括三个部分。第一个将有助于分析与PWTO和移动电离层扰动有关的电离层电子密度。第二部分使用测量从中间层低热层（TIMED/SABER温度和流星雷达风），以检测PW和GW活动，旨在证明GW和PW的可能的相互作用。将进行数值模拟以支持结果。在第三个工作范围中，对前两部分的结果进行了比较，以揭示GW对电离层的影响，并验证PW能量通过二次波的可能传输。

The investigation of the response of the thermosphere/ionosphere system (TIS) on neutral atmosphere planetary waves (PW) is the aim of this work. PW do not propagate above 130km. Despite this, oscillations with PW periods and wavenumbers (planetary wave-type oscillations, PWTO) are registered in the TIS. Thus, indirect processes must be responsible for transporting the PW energy upwards. Different possibilities are suggested in the literature, e.g. PW modulation of gravity waves (GW) and tides and modulation of the ionospheric electrojet. In this project, the GW modulation will be considered. The work described in this proposal consists of three parts. The first one will contribute with analyses on ionospheric electron densities related to PWTO and travelling ionospheric disturbances (TID). The second part uses measurements from the mesosphere-lower thermosphere (TIMED/SABER temperatures and meteor radar winds) to detect PW and GW activity, aiming to prove a possible interaction of GW and PW. Numerical modelling will be performed to support the results. In the third scope of work the results of both forgoing parts are compared to reveal the affect of GW on the ionosphere and verify the possible transport of PW energy by secondary waves.