Impact of the vertical dynamics on the thermosphere at low and middle latitudes: GITM simulations

Qingyu Zhu, Yue Deng, Astrid Maute, Cheng Sheng, Cissi Y. Lin

Research output: Contribution to journalArticlepeer-review

7 Scopus citations

Abstract

In this study, the influences of the electric fields at low and middle latitudes on the ionosphere and thermosphere are investigated by using the nonhydrostatic Global Ionosphere and Thermosphere Model (GITM). The equatorial ionization anomaly and the equatorial thermosphere anomaly (ETA) are well reproduced in the simulation when the electric fields are included. The term analysis of the continuity equation of the neutral mass density shows that the daytime upward vertical wind near the geomagnetic equator tends to increase the local neutral mass density at 400 km altitude, while the divergence in the meridional wind associated with the meridional ion-drag force tends to transport the neutral mass density away from the geomagnetic equator which might contribute to the formation of the ETA trough. The vertical dynamics is modulated by the vertical forces including ion-drag force and pressure gradient force acting on the neutrals, and the changing vertical dynamics can also feedback to vertical ion-drag and pressure gradient forces, particularly near the geomagnetic equator. The daytime vertical ion-drag force near the geomagnetic equator is generally upward, while the daytime vertical pressure gradient force near the geomagnetic equator is reduced at most times after adding in the electric fields at low and middle latitudes. Meanwhile, the sudden introduction of the electric fields at low and middle latitudes induces an acoustic wave.

Original languageEnglish
Pages (from-to)6882-6891
Number of pages10
JournalJournal of Geophysical Research: Space Physics
Volume122
Issue number6
DOIs
StatePublished - 1 Jun 2017

Keywords

  • low and middle latitudes
  • nonhydrostatic
  • vertical dynamics

Fingerprint

Dive into the research topics of 'Impact of the vertical dynamics on the thermosphere at low and middle latitudes: GITM simulations'. Together they form a unique fingerprint.

Cite this