Wave coupling between the lower atmosphere and thermosphere: Solar cycle influences (Invited) [presentation]
Forbes, J. M., & Hagan, M. E. (2009). Wave coupling between the lower atmosphere and thermosphere: Solar cycle influences (Invited) [presentation]. In AGU Fall Meeting 2009. American Geophysical Union: San Francisco, CA, US.
Ionosphere-thermosphere (IT) observations during the deep solar minimum of 2008 are punctuated by the effects of vertically-propagating waves. This is due in part to solar and geomagnetic quiescence, but also to the reduced density scale height, which influences the way in which molecular dissipa... Show moreIonosphere-thermosphere (IT) observations during the deep solar minimum of 2008 are punctuated by the effects of vertically-propagating waves. This is due in part to solar and geomagnetic quiescence, but also to the reduced density scale height, which influences the way in which molecular dissipation determines the thermospheric penetration of tides and gravity waves. This paper reviews the propagation characteristics of various-wavelength vertically-propagating waves as they enter the thermosphere over a range of solar flux conditions. The Global-Scale Wave Model (GSWM) is employed to reveal these characteristics for different Hough modes of the semidiurnal migrating tide, with vertical wavelengths between 25 and 150 km. The observed solar-cycle variation of the eastward-propagating diurnal tide with zonal wavenmber s = -3 (DE3) and 60-km vertical wavelength is interpreted within this context. Show less