Academia.eduAcademia.edu
All Topics
Earth Sciences
Atmospheric Science
Lower thermosphere

Lower thermosphere

description8 papers
group1 follower
lightbulbAbout this topic
The lower thermosphere is a region of the Earth's atmosphere located approximately 80 to 550 kilometers above the surface, characterized by increasing temperatures with altitude due to the absorption of solar radiation. It plays a crucial role in atmospheric dynamics and is involved in phenomena such as ionization and the behavior of satellites.
lightbulbAbout this topic
The lower thermosphere is a region of the Earth's atmosphere located approximately 80 to 550 kilometers above the surface, characterized by increasing temperatures with altitude due to the absorption of solar radiation. It plays a crucial role in atmospheric dynamics and is involved in phenomena such as ionization and the behavior of satellites.

Key research themes

1. How can in-situ multi-point measurements advance understanding of electrodynamics and energy transfer processes in the lower thermosphere-ionosphere (LTI) region?

This theme focuses on developing innovative observational platforms capable of performing direct in-situ measurements within the challenging altitude range of ~100-200 km, which remains poorly sampled by traditional remote sensing and short-duration sounding rockets. Understanding key electrodynamic processes such as Joule heating, energetic particle precipitation, and ion-neutral coupling in this transition region is crucial for resolving large model discrepancies, quantifying energy inputs from geomagnetic activity, and constraining spatial and temporal variability in the LTI. Multi-point observations can clarify transport processes and coupling mechanisms that govern the LTI’s thermal structure and composition, thereby improving the representation of this gateway between Earth's atmosphere and space in geospace system models.

Daedalus: A Low-Flying Spacecraft for the Exploration of the Lower Thermosphere - Ionosphere
by errico armandillo

2024, Geoscientific Instrumentation, Methods and Data Systems Discussions

Key finding: Daedalus mission concept proposes an innovative low-altitude spacecraft (~150 km and below) coupled with sub-satellite releases to provide multi-point in-situ measurements of plasma density, ion and neutral composition,... Read more
articleView PaperdownloadDownload
Investigation of energy transport and thermospheric upwelling during quiet magnetospheric and ionospheric conditions from the studies of low- and middle-altitude cusp
by Hermann Opgenoorth

2022, Annales Geophysicae

Key finding: Using combined measurements from Cluster spacecraft at 1–3 RE altitudes and CHAMP satellite in low Earth orbit (~300–450 km), this study identifies small-scale (kilometer-scale) intense field-aligned currents (FACs) in the... Read more
articleView PaperdownloadDownload
Ionosphere Influenced From Lower-Lying Atmospheric Regions
by Kateřina Potužníková

2024, Frontiers in Astronomy and Space Sciences

Key finding: Extensive observations from midlatitude stations demonstrate that atmospheric waves (e.g., gravity waves, planetary waves, and tides) generated in the lower atmosphere propagate upwards and significantly modulate ionospheric... Read more
articleView PaperdownloadDownload
keyboard_arrow_downShow more

2. What are the mechanisms and characteristics of plasma irregularities and fine-scale structures in the sporadic E (Es) layer within the lower thermosphere?

This research area investigates the formation, vertical fine structure, and temporal evolution of plasma irregularities in sporadic E layers (~90–130 km altitude). Understanding these small-scale and transient electron density fluctuations is essential because they impact ionospheric radio wave propagation and signal integrity for communication and navigation. Observations with advanced high-resolution lidars and radars reveal complex phenomena such as Kelvin-Helmholtz instabilities, neutral wind shears, and gravity wave modulations that drive these irregularities. Revealing the dynamical coupling between neutral atmospheric motions and plasma structuring elucidates how energy and momentum transport shape mesoscale ionospheric variability in the LTI.

Vertical fine structure and time evolution of plasma irregularities in the Es layer observed by a high-resolution Ca+ lidar
by katsuhiko tsuno

2022, Earth, Planets and Space

Key finding: High time (5 s) and height (15 m) resolution lidar observations of Ca+ ions in the sporadic E layer reveal fine-scale plasma structures including quasi-sinusoidal height undulations, localized clumps, and 'cat's-eye' vortex... Read more
articleView PaperdownloadDownload
Occurrence features of Intermediate descending layer and Sporadic E observed over the higher mid-latitude ionospheric station of Moscow
by Theodoros Leontiou

2023

Key finding: Long-term analysis of nine years of ionosonde data characterizes the diurnal and seasonal periodicities of intermediate descending layers (IDLs) and sporadic E (Es) layers at midlatitudes. Dominant tidal periodicities of 6,... Read more
articleView PaperdownloadDownload
The Dynamics of the Midlatitude Mesosphere and Lower Thermosphere
by Eliana Nossa

2022

Key finding: Using coordinated incoherent scatter radar campaigns at Arecibo, this Ph.D. study develops methodology to estimate neutral winds in the 95–130 km range, revealing instabilities responsible for plasma irregularities in the... Read more
articleView PaperdownloadDownload
keyboard_arrow_downShow more

3. How do thermospheric and mesospheric thermal structures respond to geomagnetic activity and climatic forcing, and what are the influences of greenhouse gases and atmospheric waves on long-term cooling trends in the lower thermosphere?

This theme explores the complex thermal balance of the mesosphere and lower thermosphere (MLT) in response to geomagnetic storms and anthropogenic influences, primarily the IR radiative cooling effects of greenhouse gases such as CO2 and NO. Observations from satellite limb instruments and ground meteor radars reveal mesospheric and lower thermospheric temperature perturbations and cooling trends linked to geomagnetic storm duration, planetary wave activity, and increased greenhouse gas concentrations. Modeling and empirical studies seek to understand the interplay of dynamical heating, radiative cooling, and atmospheric wave modulation in shaping both short-term temperature variations during storms and longer-term cooling and contraction trends related to climate change, alongside challenges in separating overlapping influences at these altitudes.

Temperature Variations in the Mesosphere and Lower Thermosphere during Geomagnetic Storms with Disparate Durations at High Latitudes
by fuzhen shen

2025, Universe

Key finding: Using SABER satellite temperature data and TIMEGCM simulations, this study demonstrates that longer-duration geomagnetic storms (e.g., April 2018 event with Kp > 4 lasting 15 hours) produced pronounced MLT temperature... Read more
articleView PaperdownloadDownload
Anthropogenic Influence on the Antarctic Mesospheric Cooling Observed during the Southern Hemisphere Minor Sudden Stratospheric Warming
by Andrey Koval

2023, Atmosphere

Key finding: Combining meteor radar, satellite limb sounder, and reanalysis data, the study reports a 26 K mesospheric cooling concurrent with a 66 K polar stratospheric warming during the 2019 Southern Hemisphere minor SSW. The cooling... Read more
articleView PaperdownloadDownload
Long-term geospace climate monitoring
by Jan Lastovicka

2024, Frontiers in Astronomy and Space Sciences

Key finding: This review synthesizes multi-decadal satellite drag data, incoherent scatter radar ion temperatures, and general circulation model simulations to expose significant cooling trends in the upper atmosphere and thermosphere... Read more
articleView PaperdownloadDownload
Infrared radiation in the mesosphere and lower thermosphere: energetic effects and coupling with lower atmosphere
by Artem G. Feofilov

2016

Key finding: The study advances non-local thermodynamic equilibrium (non-LTE) modeling of infrared emission and absorption for key radiatively active molecules (CO2, O3, H2O) in the MLT, underscoring the critical role of IR radiation... Read more
articleView PaperdownloadDownload
keyboard_arrow_downShow more

Related Topics

  • Radiative Transfer Theory
  • Planetary Atmospheres
  • Radiative transfer modeling
  • Microphysical cloud properties
  • Infrared Radiation
  • Remote Sensing

    • All papers in Lower thermosphere

    Combined ground-based optical support for the aurora (DELTA) sounding rocket campaign
    by andrew kavanagh

    2006, Earth Planets and Space

    The Japan Aerospace Exploration Agency (JAXA) DELTA rocket experiment, successfully launched from Andøya at 0033 UT on December 13, 2004, supported by ground based optical instruments, primarily 2 Fabry-Perot Interferometers (FPIs)... more
    Fig. 1. 557.7 nm emission as observed by the Finnish Meteorological Institute Kilpisjarvi ASC at 0034 UT. Also included are the projections of the sampled volumes at 110 km for the Skibotn FPI (brown triangles), Keops FPI (brown boxes), EISCAT CP2 positions (blue diamonds) and the Andoya DELTA rocket launch site (red diamond).
    Fig. 4. Lower thermosphere meridional neutral winds from 1400 UT on 12/12/04 to 0800 UT on 13/12/04, determined from the 557.7 nm emission, observed from the South direction at Skibotn (crosses with dotted line) and from the North direction at Keops (circles with solid line). Winds are positive in the Southward direction. “ig. 3. _ Lower thermosphere neutral temperatures from 1400 UT on 12/12/04 to 0800 UT on 13/12/04, determined from the 557.7 nm emis- sion, observed from the South direction at Skibotn (crosses with dotted line) and from the North direction at Keops (circles with solid line).
    Fig. 5. The top plot shows the 557.7 nm emission relative intensity from 1400 UT on 12/12/04 to 0800 UT on 13/12/04 observed from the South direction at Skibotn (crosses with dotted line) and from the North direction at Keops (circles with solid line). An arbitrary scaling factor has been applied. The bottom plot shows the X-component of magnetic deflection from the Kiruna magnetometer for the same period.
    Fig. 6. Lower thermosphere neutral temperatures from 2200 UT on 12/12/04 to 0200 UT on 13/12/04 from Keops North observations (crosses with solid line) and Skibotn South observations (plusses with dotted line) compared to EISCAT ion temperatures from the CP2 di- rections (Eastmost—circles, Southmost—boxes, Vertical—diamonds. Field-aligned—filled dots) at 126 km. Fig. 8. As for Fig. 6 but EISCAT ion temperatures are from 115 km.
    Fig. 7. As for Fig. 6 but EISCAT ion temperatures are from 120 km.
    Fig. 9. As for Fig. 6 but EISCAT ion temperatures are from 110 km.
    Fig. 10. All sky camera images from (a) Skibotn from the SCASI instrument at 003301 UT and (b) ASC at Keops at 003308 UT. The orientations are indicated on both images.
    Fig. 11. Lower thermosphere neutral temperatures from 2300 UT on 12/12/04 to 0200 UT on 13/12/04, observed from the West direction at Skibotn (crosses with heavy dotted line) and from the North-West di- rection at Keops (circles with light dotted line). Error bars are included for each set of measurements. Fig. 12. Lower thermosphere neutral temperatures from 2300 UT on 12/12/04 to 0200 UT on 13/12/04, observed from the South direction at Skibotn (crosses with heavy dotted line) and from the North direction at Keops (circles with light dotted line). Error bars are included for each set of measurements.
    Fig. 13. Combined neutral temperatures from Skibotn from 2300 UT on 12/12/04 to 0200 UT on 13/12/04. Temperatures to the North (circles with solid line), East (crosses with light dotted line), South (boxes with heavy dotted line) and West (diamonds with dash-dot line) have error bars included.
    Fig. 14. Combined neutral winds from Skibotn from 2300 UT on 12/12/04 to 0200 UT on 13/12/04, for the North (circles with solid line), East (crosses with light dotted line), South (boxes with heavy dotted line) and West (diamonds with dash-dot line). Meridional winds are considered positive Southward, zonal winds are considered positive Eastward.
    Fig. 15. Zenith neutral winds from the Skibotn FPI for the period from from 1400 UT on 12/12/04 to 0800 UT on 13/12/04, upwards consid- ered positive. The region highlighted by the heavier line is from 0000 to 0100 UT on 13/12/04.
    descriptionView Paperarrow_downwardDownload
    Download research papers for free!
    580 California St., Suite 400
    San Francisco, CA, 94104