Forcing mechanisms of the migrating quarterdiurnal tide

Geißler, Christoph; Jacobi, Ch.; Lilienthal, Friederike

doi:10.5194/angeo-38-527-2020

Cited by 10 publications

(10 citation statements)

References 51 publications

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“…Secondary sources, such as nonlinear tide-tide interactions and gravity wave-tide interactions, can also play a role. Geißler et al (2020) have used the same GCM to study the forcing mechanisms of the migrating quarterdiurnal tide (QDT). Among the studied mechanisms were the absorption of solar radiation by ozone and water vapor, nonlinear tidal interactions, and gravity wave-tide interactions.…”

Section: Modeling Of Vertical Coupling By Wavesmentioning

confidence: 99%

Role Of the Sun and the Middle atmosphere/thermosphere/ionosphere In Climate (ROSMIC): a retrospective and prospective view

Ward

Seppälä

Yiğit

et al. 2021

Prog Earth Planet Sci

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While knowledge of the energy inputs from the Sun (as it is the primary energy source) is important for understanding the solar-terrestrial system, of equal importance is the manner in which the terrestrial part of the system organizes itself in a quasi-equilibrium state to accommodate and re-emit this energy. The ROSMIC project (2014–2018 inclusive) was the component of SCOSTEP’s Variability of the Sun and Its Terrestrial Impact (VarSITI) program which supported research into the terrestrial component of this system. The four themes supported under ROSMIC are solar influence on climate, coupling by dynamics, trends in the mesosphere lower thermosphere, and trends and solar influence in the thermosphere. Over the course of the VarSITI program, scientific advances were made in all four themes. This included improvements in understanding (1) the transport of photochemically produced species from the thermosphere into the lower atmosphere; (2) the manner in which waves produced in the lower atmosphere propagate upward and influence the winds, dynamical variability, and transport of constituents in the mesosphere, ionosphere, and thermosphere; (3) the character of the long-term trends in the mesosphere and lower thermosphere; and (4) the trends and structural changes taking place in the thermosphere. This paper reviews the progress made in these four areas over the past 5 years and summarizes the anticipated research directions in these areas in the future. It also provides a physical context of the elements which maintain the structure of the terrestrial component of this system. The effects that changes to the atmosphere (such as those currently occurring as a result of anthropogenic influences) as well as plausible variations in solar activity may have on the solar terrestrial system need to be understood to support and guide future human activities on Earth.

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Section: Modeling Of Vertical Coupling By Wavesmentioning

confidence: 99%

Role Of the Sun and the Middle atmosphere/thermosphere/ionosphere In Climate (ROSMIC): a retrospective and prospective view

Ward

Seppälä

Yiğit

et al. 2021

Prog Earth Planet Sci

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“…Despite receiving less attention in comparison to the lower‐order migrating tides, QW4 is a persistent feature in the mesosphere and lower thermosphere and is characterized by its long vertical wavelengths, which allow it to propagate to higher altitudes. The major forcing mechanism of QW4 is the absorption of solar radiation by ozone in the stratosphere (GeiBler et al., 2020; Xu et al., 2012). It should be noted that QW4 has a weaker amplitude than the lower‐order migrating tides with s = 1, s = 2, and s = 3 (M. Liu et al., 2015; Azeem et al., 2016).…”

Section: Resultsmentioning

confidence: 99%

On the Variation of Column Density Ratio ΣO/N₂ in the Upper Atmosphere Using Principal Component Analysis in 2‐Dimensional Images

Goel

Harding

et al. 2023

JGR Space Physics

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The variability of the thermosphere on a daily basis is influenced by a variety of factors, including solar, geomagnetic, and meteorological drivers. The column density ratio of atomic oxygen to molecular nitrogen (ΣO/N2) is a useful parameter for quantifying this variability, and has been shown to closely correspond to F‐region electron density, total electron content, and upper atmospheric transport. Despite the significance of the ΣO/N2, the relative contributions of these drivers to thermospheric variability are not well understood. In order to shed light on this issue, principal component analysis was performed in this study to distinguish and rank the various sources of variability in the ΣO/N2. The analysis was based on the ΣO/N2 data from the Global‐scale Observations of the Limb and Disk mission from days 81–135 of 2020. The resulting two‐dimensional eigen spatial patterns reveal the dominant variabilities during the specified period. The first six principal components are reported and associated with the major drivers through their spatial and temporal features. Geomagnetic storms, interhemispheric transport, atmospheric tides, and planetary waves were identified as the drivers of the first, second, third, and fifth components, respectively. The order of these components highlights that geomagnetic activity is the dominant source of daily variability in the ΣO/N2, followed by interhemispheric transport and meteorological drivers from the lower atmosphere.

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“…Model diagnostics indicate that the non-linear tidal interactions contribute to the generation of the quaddiurnal tides (e.g., Smith et al, 2004). However, Geißler et al (2020) found through numerical experiments that solar forcing is the most important mechanism in generating quaddiurnal tides in the MLT region, and non-linear interactions and gravity waves can be important during September equinox conditions. Not much is known about the quaddiurnal tide in the upper thermosphere.…”

Section: Introductionmentioning

confidence: 99%

Delineating the effect of upward propagating migrating solar tides with the TIEGCM-ICON

Maute

Forbes²,

Cullens³

et al. 2023

Front. Astron. Space Sci.

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Introduction: The vertical coupling of the lower and upper atmosphere via atmospheric solar tides is very variable and affects the thermosphere and ionosphere system. In this study, we use Ionospheric Connection (ICON) explorer data from 220–270 Day Of Year (DOY), 2020 when large changes in the migrating semidiurnal tide (SW2) and the zonal and diurnal mean (ZM) zonal wind occur within 8 days.Method: We use the ICON Level4 product, the thermosphere-ionosphere-electrodynamics general circulation model (TIEGCM) driven by tides fitted to ICON observations via the Hough Mode Extension (HME) method. The effect of the upward propagating tides is isolated by examining the difference between two TIEGCM simulations with and without tidal HME forcing at the model lower boundary.Results: The simulations reveals that the solar SW2 changes its latitudinal structure at 250 after DOY 232 from two peaks at mid latitudes to one broad low latitude peak, while at 110 km the two-peak structure persists. The ZM zonal wind at 250 km undergoes a similar dramatic change. These SW2 changes are associated with the prevalence of antisymmetric HMEs after DOY 232. The migrating diurnal, terdiurnal and quaddiurnal tides at 250 km undergo similar variations as SW2. TW3 is strong in the thermosphere and most likely caused by non-linear tidal interaction between DW1 and SW2 above 130 km. Surprisingly, the solar in situ forcing of TW3 and SW2 in the upper thermosphere is not nearly as important as their upward propagating tidal component. Associated with the strong dynamical changes, the zonal and diurnal mean NmF2 decreases by approximately 15%–20%, which has a major contribution from the O/N2 decrease by roughly 10%. These changes are stronger than general seasonal behavior.Discussion: While studies have reported on the dynamical changes via SW2 in the mesosphere-lower thermosphere (MLT) region during the equinox transition period, this study is, to our knowledge, the first to examine the effects of rapid changes in SW2 on the upper thermosphere and ionosphere. The study highlights the potential of using ICON-TIEGCM for scientific studies.

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Forcing mechanisms of the migrating quarterdiurnal tide

Cited by 10 publications

References 51 publications

Role Of the Sun and the Middle atmosphere/thermosphere/ionosphere In Climate (ROSMIC): a retrospective and prospective view

Role Of the Sun and the Middle atmosphere/thermosphere/ionosphere In Climate (ROSMIC): a retrospective and prospective view

On the Variation of Column Density Ratio ΣO/N₂ in the Upper Atmosphere Using Principal Component Analysis in 2‐Dimensional Images

Delineating the effect of upward propagating migrating solar tides with the TIEGCM-ICON

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Forcing mechanisms of the migrating quarterdiurnal tide

Cited by 10 publications

References 51 publications

Role Of the Sun and the Middle atmosphere/thermosphere/ionosphere In Climate (ROSMIC): a retrospective and prospective view

Role Of the Sun and the Middle atmosphere/thermosphere/ionosphere In Climate (ROSMIC): a retrospective and prospective view

On the Variation of Column Density Ratio ΣO/N2 in the Upper Atmosphere Using Principal Component Analysis in 2‐Dimensional Images

Delineating the effect of upward propagating migrating solar tides with the TIEGCM-ICON

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On the Variation of Column Density Ratio ΣO/N₂ in the Upper Atmosphere Using Principal Component Analysis in 2‐Dimensional Images