[P-EM11] Coupling Processes in the Atmosphere-Ionosphere System

[PEM11-25] Studying the daytime low latitude neutral wind dynamo with ICON observations and WACCM-X

★Invited Papers

*Astrid I Maute¹、Brian Harding²、Roderick Heelis³、Jeffrey Forbes⁴、Thomas Immel²、Joanne Wu² (1.High Altitude Observatory, National Center for Atmospheric Research, Boulder, CO, USA.、2.Space Science Laboratory, University of California, Berkeley, CA, USA.、3.University of Texas, Dallas, TX, USA.、4.University of Colorado, Boulder, CO, USA.)

キーワード：Low latitude daytime wind dynamo, ICON observations & WACCM-X simulations

During the daytime the low latitude vertical ion drift is responsible for lifting up the plasma, which then diffuses down along the magnetic field line forming the characteristic equatorial ionization anomalies. The low latitude ion drift is influenced by the global neutral wind dynamo and the high latitude magnetosphere-ionosphere coupling, and varies on time scales from days to seasons. It is well known that the highly variable neutral wind in the 90-150 km altitude range is dominated by upward propagating waves and tides from the lower atmosphere. It is still not fully understood how the ion drift variation is related to the neutral wind variation.

In this presentation we use observations from the Ionospheric CONnection explorer (ICON) mission designed to study, among others, the lower to upper atmosphere coupling by measuring key parameters, such as the ion drift and the neutral winds, in the low to middle latitude region. We focus on concurrent observed daytime ion drift and neutral winds to study the relationship of longitudinal and day-to-day variations in the ion drift and neutral wind. We employ the Whole Atmosphere Community Climate Model-Extended (WACCM-X) to better understand and quantify contributing factors such as the influence of the geomagnetic main field and the observing geometry. We conclude by discussing our result in a more general context.