MIPAS observations of longitudinal oscillations in the mesosphere and the lower thermosphere: climatology of odd-parity daily frequency modes

Abstract

Abstract. MIPAS global Sun-synchronous observations are almost fixed in local time. Subtraction of the descending and ascending node measurements at each longitude only includes the longitudinal oscillations with odd daily frequencies n odd from the Sun's perspective at 10:00. Contributions from the background atmosphere, daily-invariant zonal oscillations and tidal modes with even-parity daily frequencies vanish. We have determined longitudinal oscillations in MI-PAS temperature with n odd and wavenumber k = 0-4 from the stratosphere to 150 km from April 2007 to March 2012. To our knowledge, this is the first time zonal oscillations in temperature have been derived pole to pole in this altitude range from a single instrument. The major findings are the detection of (1) migrating tides at northern and southern high latitudes; (2) significant k = 1 activity at extratropical and high latitudes, particularly in the Southern Hemisphere; (3) k = 3 and k = 4 eastward-propagating waves that penetrate the lower thermosphere with a significantly larger vertical wavelength than in the mesosphere; and (4) a migrating tide quasi-biennial oscillation in the stratosphere, mesosphere and lower thermosphere. MIPAS global measurements of longitudinal oscillations are useful for testing tide modeling in the mesosphere and lower thermosphere region and as a lower boundary for models extending higher up in the atmosphere.

Michelson Interferometer for Passive Atmospheric Sounding Institute of Meteorology and Climate Research/Instituto de Astrofísica de Andalucía version 8 retrieval of nitric oxide and lower-thermospheric temperature

“…The resulting 5.3 µm temperature product represents one of the very few available global kinetic temperature datasets in the lower and middle thermosphere. MIPAS NO and thermospheric temperature data have been used widely in a variety of scientific studies (Funke et al, 2010(Funke et al, , 2011von Clarmann et al, 2013;Oberheide et al, 2013;Xu et al, 2013;Funke et al, 2014;García-Comas et al, 2016;Kli-menko et al, 2019;Pettit et al, 2019;Emmert et al, 2021;Sinnhuber et al, 2021).…”

On the Roles of Advection and Solar Heating in Seasonal Variation of the Migrating Diurnal Tide in the Stratosphere, Mesosphere, and Lower Thermosphere

“…However, the tidal amplitudes in this region show large discrepancy among the models. The Sun-synchronous Michelson Interferometer for Passive Atmospheric Sounding (MIPAS) can provide superposition of tidal components with odd frequency up to 150 km, but does not allow the separation of individual tidal components [40]. Although a full characterization of the thermosphere wave spectrum has to await future dedicated satellite missions; e.g., Global-scale observations of the Limb and Disk (GOLD, launched on 25 Jan 2018) and Ionospheric Connection Explorer (ICON, to be launched on 7 Nov 2018)-it is nevertheless useful to analyze the tidal fields in this region from self-consistent GCMs to investigate their physical mechanisms.…”