scholarly journals The O(1 S) 297.2-nm Dayglow Emission: A Tracer of CO2 Density Variations in the Martian Lower Thermosphere

2018 ◽  
Vol 123 (12) ◽  
pp. 3119-3132 ◽  
Author(s):  
L. Gkouvelis ◽  
J.-C. Gérard ◽  
B. Ritter ◽  
B. Hubert ◽  
N. M. Schneider ◽  
...  
Keyword(s):  
Lower Thermosphere ◽  
Co2 Density

scholarly journals Identification of the mechanisms responsible for anomalies in the tropical lower thermosphere/ionosphere caused by the January 2009 sudden stratospheric warming

2019 ◽  
Vol 9 ◽  
pp. A39 ◽  
Author(s):  
Maxim V. Klimenko ◽  
Vladimir V. Klimenko ◽  
Fedor S. Bessarab ◽  
Timofei V. Sukhodolov ◽  
Pavel A. Vasilev ◽  
...  
Keyword(s):  
Electric Field ◽  
Phase Change ◽  
Lower Thermosphere ◽  
Upper Atmosphere ◽  
Electron Content ◽  
Stratospheric Warming ◽  
Sudden Stratospheric Warming ◽  
Low Latitude ◽  
Plasma Drift ◽  
Solar Tide

We apply the Entire Atmosphere GLobal (EAGLE) model to investigate the upper atmosphere response to the January 2009 sudden stratospheric warming (SSW) event. The model successfully reproduces neutral temperature and total electron content (TEC) observations. Using both model and observational data, we identify a cooling in the tropical lower thermosphere caused by the SSW. This cooling affects the zonal electric field close to the equator, leading to an enhanced vertical plasma drift. We demonstrate that along with a SSW-related wind disturbance, which is the main source to form a dynamo electric field in the ionosphere, perturbations of the ionospheric conductivity also make a significant contribution to the formation of the electric field response to SSW. The post-sunset TEC enhancement and pre-sunrise electron content reduction are revealed as a response to the 2009 SSW. We show that at post-sunset hours the SSW affects low-latitude TEC via a disturbance of the meridional electric field. We also show that the phase change of the semidiurnal migrating solar tide (SW2) in the neutral wind caused by the 2009 SSW at the altitude of the dynamo electric field generation has a crucial importance for the SW2 phase change in the zonal electric field. Such changes lead to the appearance of anomalous diurnal variability of the equatorial electromagnetic plasma drift and subsequent low-latitudinal TEC disturbances in agreement with available observations. Plain Language Summary – Entire Atmosphere GLobal model (EAGLE) interactively calculates the troposphere, stratosphere, mesosphere, thermosphere, and plasmasphere–ionosphere system states and their response to various natural and anthropogenic forcing. In this paper, we study the upper atmosphere response to the major sudden stratospheric warming that occurred in January 2009. Our results agree well with the observed evolution of the neutral temperature in the upper atmosphere and with low-latitude ionospheric disturbances over America. For the first time, we identify an SSW-related cooling in the tropical lower thermosphere that, in turn, could provide additional information for understanding the mechanisms for the generation of electric field disturbances observed at low latitudes. We show that the SSW-related vertical electromagnetic drift due to electric field disturbances is a key mechanism for interpretation of an observed anomalous diurnal development of the equatorial ionization anomaly during the 2009 SSW event. We demonstrate that the link between thermospheric winds and the ionospheric dynamo electric field during the SSW is attained through the modulation of the semidiurnal migrating solar tide.

scholarly journals Large-Scale Waves in the Mesosphere and Lower Thermosphere Observed by SABER

2005 ◽  
Vol 62 (12) ◽  
pp. 4384-4399 ◽  
Author(s):  
Rolando R. Garcia ◽  
Ruth Lieberman ◽  
James M. Russell ◽  
Martin G. Mlynczak
Keyword(s):  
Large Scale ◽  
Middle Atmosphere ◽  
Lower Thermosphere ◽  
Normal Modes ◽  
Zonal Winds ◽  
Broadband Emission ◽  
Summer Hemisphere ◽  
Mean Structure ◽  
Mesosphere And Lower Thermosphere ◽  
The Tropics

Abstract Observations made by the Sounding of the Atmosphere using Broadband Emission Radiometry (SABER) instrument on board NASA’s Thermosphere–Ionosphere–Mesosphere Energetics and Dynamics (TIMED) satellite have been processed using Salby’s fast Fourier synoptic mapping (FFSM) algorithm. The mapped data provide a first synoptic look at the mean structure and traveling waves of the mesosphere and lower thermosphere (MLT) since the launch of the TIMED satellite in December 2001. The results show the presence of various wave modes in the MLT, which reach largest amplitude above the mesopause and include Kelvin and Rossby–gravity waves, eastward-propagating diurnal oscillations (“non-sun-synchronous tides”), and a set of quasi-normal modes associated with the so-called 2-day wave. The latter exhibits marked seasonal variability, attaining large amplitudes during the solstices and all but disappearing at the equinoxes. SABER data also show a strong quasi-stationary Rossby wave signal throughout the middle atmosphere of the winter hemisphere; the signal extends into the Tropics and even into the summer hemisphere in the MLT, suggesting ducting by westerly background zonal winds. At certain times of the year, the 5-day Rossby normal mode and the 4-day wave associated with instability of the polar night jet are also prominent in SABER data.

Horizontal extension of acoustic resonance between the ground and the lower thermosphere

2012 ◽  
Vol 75-76 ◽  
pp. 127-132 ◽  
Author(s):  
Mitsuru Matsumura ◽  
Hiroyuki Shinagawa ◽  
Toshihiko Iyemori
Keyword(s):  
Lower Thermosphere ◽  
Acoustic Resonance

Supercritical CO2 regeneration of activated carbon loaded with organic adsorbates

1997 ◽  
Vol 35 (7) ◽  
pp. 261-268 ◽  
Author(s):  
Kazuyuki Chihara ◽  
Kanji Oomori ◽  
Takao Oono ◽  
Yosuke Mochizuki
Keyword(s):  
Activated Carbon ◽  
Cost Estimation ◽  
Supercritical Co2 ◽  
Adsorption Equilibrium ◽  
Equilibrium Constants ◽  
Adsorption Dynamics ◽  
Boiling Points ◽  
Organic Adsorbates ◽  
Carbon Regeneration ◽  
Co2 Density

Supercritical CO2 regeneration is one of the possibilities for spent carbon regeneration loaded with some organics. Here, adsorption equilibrium and adsorption dynamics were evaluated for some typical organic pollutants under some supercritical CO2 conditions. A supercritical CO2 chromatograph packed with activated carbon (F-400, CAL) was used to detect the pulse responses of organics, which were analyzed by moment analysis. Adsorption equilibrium constants of some organics varied with CO2 density and their boiling points. Possibility of regeneration of each substance was discussed. Cost estimation was necessary and was the key point of this technique.

scholarly journals Some results of comparison between the lower thermosphere zonal winds as seen by the ground-based radars and WINDII on UARS

1999 ◽  
Vol 51 (7-8) ◽  
pp. 701-709 ◽  
Author(s):  
Yu. I. Portnyagin ◽  
T. V. Solovjova ◽  
D. Y. Wang
Keyword(s):  
Lower Thermosphere ◽  
Zonal Winds

Climatological modeling of horizontal winds in the mesosphere and lower thermosphere over a mid-latitude station in China

2015 ◽  
Vol 56 (7) ◽  
pp. 1354-1365 ◽  
Author(s):  
Xin Yao ◽  
Tao Yu ◽  
Biqiang Zhao ◽  
You Yu ◽  
Libo Liu ◽  
...  
Keyword(s):  
Lower Thermosphere ◽  
Latitude Station ◽  
Mesosphere And Lower Thermosphere

The wind regime of the mesosphere and lower thermosphere during the DYANA campaign—II. Semi-diurnal tide

1994 ◽  
Vol 56 (13-14) ◽  
pp. 1731-1752 ◽  
Author(s):  
Yu.I. Portnyagin ◽  
N.A. Makarov ◽  
R.P. Chebotarev ◽  
A.M. Nikonov ◽  
E.S. Kazimirovsky ◽  
...  
Keyword(s):  
Lower Thermosphere ◽  
Diurnal Tide ◽  
Wind Regime ◽  
Mesosphere And Lower Thermosphere
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