Interhemispheric differences of mesosphere/lower thermosphere
winds and tides investigated from three whole atmosphere models
and meteor radar observations

Stober, Gunter; Kuchař, Aleš; Pokhotelov, Dimitry; Liu, Huixin; Liu, Hanli; Schmidt, Hauke; Jacobi, Ch.; Baumgarten, Kathrin; Brown, Peter; Janches, Diego; Murphy, D. J.; Kozlovsky, Alexander; Lester, M.; Belova, Evgenia; Kero, Johan

doi:10.5194/acp-2021-142

Cited by 2 publications

(3 citation statements)

References 74 publications

(116 reference statements)

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“…In simulations without eddy diffusion, the summertime amplitude maximum is much broader than observation, with amplitudes beginning to increase as early as May. Tidal dissipation by eddy diffusion may therefore be an important factor contributing to the summertime discrepancies between modeled and observed semidiurnal tides (e.g., Pancheva et al., 2020; Stober et al., 2020, 2021).…”

Section: Conclusion and Discussionmentioning

confidence: 97%

“…Many recent studies are in part driven by the increasing availability of high‐altitude and tide‐resolving general circulation models. A challenging aspect of using such models is that the representation of the SW2 tide can vary significantly from model to model (McCormack et al., 2021; Pancheva et al., 2020; Stober et al., 2021), while the cause of these differences is often obscured by the complexity of the models.…”

Section: Introductionmentioning

confidence: 99%

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The Mid‐ to High‐Latitude Migrating Semidiurnal Tide: Results From a Mechanistic Tide Model and SuperDARN Observations

et al. 2022

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Atmospheric tides are global-scale waves whose periods are an integer fraction of a solar day (Chapman & Lindzen, 1970). The tides are forced primarily by radiative and latent heating effects in the lower atmosphere (Hagan, 1996), but obtain their largest amplitudes in the mesosphere-lower-thermosphere (MLT) region (80-120 km altitude). There they are expressed as pronounced oscillations in a broad range of atmospheric fields, such as density, pressure, and wind. The migrating tides are those tides which follow the apparent motion of the sun, having a longitudinal zonal wavenumber (S) and latitudinal spherical harmonic (Hough mode) structure. In the current work, the focus lies on the migrating semidiurnal (SW2; for Semidiurnal, Westward S = 2) tide. The SW2 tidal winds maximize in the mid-and high-latitude MLT (Manson et al., 2002;Wu et al., 2011), where they form a major source of day-to-day and inter-seasonal variability of the MLT-ionosphere system (Arras et al., 2009;G. Shepherd et al., 1998;Smith, 2012). The SW2 tide is recognized as an important vertical coupling mechanism (Forbes, 2009;Pedatella & Forbes, 2010), and as a contributing factor to the vertical mixing and energy budget of the upper atmosphere (Becker, 2017;Forbes et al., 1993).The numerical study of the SW2 tide has a long history (e.g., Forbes & Garrett, 1979). Nevertheless, open questions remain about the mechanisms governing the tide's seasonal and short-term variability (

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Section: Conclusion and Discussionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

The Mid‐ to High‐Latitude Migrating Semidiurnal Tide: Results From a Mechanistic Tide Model and SuperDARN Observations

et al. 2022

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“…Daily mean temperatures and tidal amplitudes were derived by an adaptive spectral filter similar to Pokhotelov et al (2018); Baumgarten and Stober (2019); Stober et al (2020). The geopotential altitudes from NAVGEM-HA were converted into geometric heights (Stober et al, 2021). The temporal resolution of 3 hours for both model data were kept.…”

Section: Merra2 and Navgem-hamentioning

confidence: 99%

Continuous temperature soundings at the stratosphere and lower mesosphere with a ground-based radiometer considering the Zeeman effect

Krochin

Navas-Guzmán

Kuhl

et al. 2021

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Abstract. Continuous temperature observations at the stratosphere and lower mesosphere are rare. Radiometry opens the possibility by observing microwave emissions from two oxygen lines to retrieve temperature profiles at all altitudes. In this study, we present observations performed with a temperature radiometer (TEMPERA) at the Meteoswiss station at Payerne for the period from 2014 to 2017. We reanalyzed these observations with a recently developed and improved retrieval algorithm accounting for the Zeeman line splitting in the line center of both oxygen emission lines at 52.5424 and 53.0669 GHz. The new temperature retrievals were validated against MERRA2 reanalysis and the meteorological analysis NAVGEM-HA. The comparison confirmed that the new algorithm yields an increased measurement response up to an altitude of 53–55 km, which extends the altitude coverage by 8–10 km compared to previous retrievals without considering the Zeeman effect. Furthermore, we found correlation coefficients comparing the TEMPERA temperatures with MERRA2 and NAVGEM-HA for monthly mean profiles to be in the range of 0.8–0.96. In addition, mean temperature biases of 1 K and −2 K were found between TEMPERA and both models (MERRA2 and NAVGEM-HA), respectively. We also identified systematic altitude-dependent cold and warm biases compared to both model data sets.

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Interhemispheric differences of mesosphere/lower thermosphere winds and tides investigated from three whole atmosphere models and meteor radar observations

Cited by 2 publications

References 74 publications

The Mid‐ to High‐Latitude Migrating Semidiurnal Tide: Results From a Mechanistic Tide Model and SuperDARN Observations

The Mid‐ to High‐Latitude Migrating Semidiurnal Tide: Results From a Mechanistic Tide Model and SuperDARN Observations

Continuous temperature soundings at the stratosphere and lower mesosphere with a ground-based radiometer considering the Zeeman effect

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