Wave Steepening in Ionospheric Total Electron Density due to the 21 August 2017 Total Solar Eclipse

2021 ◽  
Vol 126 (3) ◽  
Author(s):  
Yang‐Yi Sun ◽  
Mitchell M. Shen ◽  
Yu‐Lin Tsai ◽  
Chi‐Yen Lin ◽  
Min‐Yang Chou ◽  
...  
Keyword(s):  
Electron Density ◽  
Solar Eclipse ◽  
Total Solar Eclipse ◽  
Total Electron Density ◽  
Total Electron

scholarly journals Evidence of gravity waves into the atmosphere during the March 2006 total solar eclipse

2007 ◽  
Vol 7 (18) ◽  
pp. 4943-4951 ◽  
Author(s):  
C. S. Zerefos ◽  
E. Gerasopoulos ◽  
I. Tsagouri ◽  
B. E. Psiloglou ◽  
A. Belehaki ◽  
...  
Keyword(s):  
Relative Humidity ◽  
Electron Density ◽  
Gravity Waves ◽  
Solar Eclipse ◽  
Stratospheric Ozone ◽  
Thermal Fluctuations ◽  
Ozone Layer ◽  
Total Solar Eclipse ◽  
Electron Content ◽  
Total Electron

Abstract. This study aims at providing experimental evidence, to support the hypothesis according to which the movement of the moon's shadow sweeping the ozone layer at supersonic speed, during a solar eclipse, creates gravity waves in the atmosphere. An experiment was conducted to study eclipse induced thermal fluctuations in the ozone layer (via measurements of total ozone column, ozone photolysis rates and UV irradiance), the ionosphere (Ionosonde Total Electron Content – ITEC, peak electron density height – hmF2), and the troposphere (temperature, relative humidity), before, during and after the total solar eclipse of 29 March 2006. We found the existence of eclipse induced dominant oscillations in the parameters related to the ozone layer and the ionosphere, with periods ranging between 30–40 min. Cross-spectrum analyses resulted to statistically significant square coherences between the observed oscillations, strengthening thermal stratospheric ozone forcing as the main mechanism for GWs. Additional support for a source below the ionosphere was provided by the amplitude of the oscillations in the ionospheric electron density, which increased upwards from 160 to 220 km height. Even though similar oscillations were shown in surface temperature and relative humidity data, no clear evidence for tropospheric influence could be derived from this study, due to the modest amplitude of these waves and the manifold rationale inside the boundary layer.

scholarly journals Evidence of gravity waves into the atmosphere during the March 2006 total solar eclipse

2007 ◽  
Vol 7 (3) ◽  
pp. 7603-7624 ◽  
Author(s):  
C. S. Zerefos ◽  
E. Gerasopoulos ◽  
I. Tsagouri ◽  
B. Psiloglou ◽  
A. Belehaki ◽  
...  
Keyword(s):  
Electron Density ◽  
Gravity Waves ◽  
Solar Eclipse ◽  
Ozone Layer ◽  
Total Solar Eclipse ◽  
Electron Content ◽  
Supersonic Speed ◽  
Ionospheric Electron Density ◽  
Total Electron ◽  
Phase Spectra

Abstract. This study aims at testing the hypothesis according to which the movement of the moon's shadow sweeping the ozone layer at supersonic speed during a solar eclipse creates gravity waves in the atmosphere. An experiment was conducted to study fluctuations of the ozone layer, the Ionosonde Total Electron Content (ITEC) and the peak electron density height (hmF2) in the ionosphere, as well as at a number of other parameters before, during and after the total solar eclipse. We found the existence of dominant oscillations with periods ranging between 30–40 min in most of the parameters. Cross-spectrum analyses between total ozone and various atmospheric parameters resulted to statistically significant square coherences between the observed oscillations, while the respective phase spectra show that the perturbation originates in the stratosphere and reaches the various layers at speeds around 20 km min−1. Additional evidence supporting these findings was provided by the amplitude of the oscillations in the ionospheric electron density, which increased upwards from 160 to 220 km height.

Revisiting the charge density analysis of 2,5-dichloro-1,4-benzoquinone at 20 K

2017 ◽  
Vol 73 (4) ◽  
pp. 654-659 ◽  
Author(s):  
Zhijie Chua ◽  
Bartosz Zarychta ◽  
Christopher G. Gianopoulos ◽  
Vladimir V. Zhurov ◽  
A. Alan Pinkerton
Keyword(s):  
Charge Density ◽  
Electron Density ◽  
Topological Analysis ◽  
Diffraction Measurement ◽  
X Ray Diffraction ◽  
Total Electron Density ◽  
Total Electron ◽  
Structure Factors ◽  
Density Analysis ◽  
Experimental Charge Density

A high-resolution X-ray diffraction measurement of 2,5-dichloro-1,4-benzoquinone (DCBQ) at 20 K was carried out. The experimental charge density was modeled using the Hansen–Coppens multipolar expansion and the topology of the electron density was analyzed in terms of the quantum theory of atoms in molecules (QTAIM). Two different multipole models, predominantly differentiated by the treatment of the chlorine atom, were obtained. The experimental results have been compared to theoretical results in the form of a multipolar refinement against theoretical structure factors and through direct topological analysis of the electron density obtained from the optimized periodic wavefunction. The similarity of the properties of the total electron density in all cases demonstrates the robustness of the Hansen–Coppens formalism. All intra- and intermolecular interactions have been characterized.

scholarly journals Ionospheric response to total solar eclipse of 22 July 2009 in different Indian regions

2013 ◽  
Vol 31 (9) ◽  
pp. 1549-1558 ◽  
Author(s):  
S. Kumar ◽  
A. K. Singh ◽  
R. P. Singh
Keyword(s):  
Total Electron Content ◽  
Solar Eclipse ◽  
Total Solar Eclipse ◽  
Lower Atmosphere ◽  
Electron Content ◽  
Vertical Total Electron Content ◽  
Total Electron ◽  
Ionospheric Response ◽  
Total Electron Content Data ◽  
Photoionization Process

Abstract. The variability of ionospheric response to the total solar eclipse of 22 July 2009 has been studied analyzing the GPS data recorded at the four Indian low-latitude stations Varanasi (100% obscuration), Kanpur (95% obscuration), Hyderabad (84% obscuration) and Bangalore (72% obscuration). The retrieved ionospheric vertical total electron content (VTEC) shows a significant reduction (reflected by all PRNs (satellites) at all stations) with a maximum of 48% at Varanasi (PRN 14), which decreases to 30% at Bangalore (PRN 14). Data from PRN 31 show a maximum of 54% at Kanpur and 26% at Hyderabad. The maximum decrement in VTEC occurs some time (2–15 min) after the maximum obscuration. The reduction in VTEC compared to the quiet mean VTEC depends on latitude as well as longitude, which also depends on the location of the satellite with respect to the solar eclipse path. The amount of reduction in VTEC decreases as the present obscuration decreases, which is directly related to the electron production by the photoionization process. The analysis of electron density height profile derived from the COSMIC (Constellation Observing System for Meteorology, Ionosphere & Climate) satellite over the Indian region shows significant reduction from 100 km altitude up to 800 km altitude with a maximum of 48% at 360 km altitude. The oscillatory nature in total electron content data at all stations is observed with different wave periods lying between 40 and 120 min, which are attributed to gravity wave effects generated in the lower atmosphere during the total solar eclipse.

Electron densities and the VSEPR model of molecular geometry

1992 ◽  
Vol 70 (3) ◽  
pp. 742-750 ◽  
Author(s):  
R. J. Gillespie
Keyword(s):  
Electron Density ◽  
Present Status ◽  
Electron Pair ◽  
Molecular Geometry ◽  
Physical Basis ◽  
Valence Shell ◽  
Electron Densities ◽  
Total Electron Density ◽  
Total Electron

This paper reviews the present status of the VSEPR model of molecular geometry in relation to electron densities. The discussion is based on the electron pair domain version of this model. The fundamental postulates of the model are summarized and illustrated by a discussion of the structures of some molecules with five and seven electron pair domains in the valence shell, including the recently discovered ions XeF5− and XeOF6−. The total electron density does not provide any obvious support for the model and although electron density deformation maps do provide some support they are not always reliable. The Laplacian of the electron density, however, shows the presence of valence shell charge concentrations that correspond closely in number and properties to the electron pair domains of the VSEPR model. This correspondence between electron pair domains and valence shell charge concentrations provides a physical basis for a better understanding of the VSEPR model. Keywords: VSEPR model, electron densities, molecular geometry, Laplacian of the electron density, electron pair domain.

scholarly journals Mapping prominence plasma parameters from eclipse observations

2013 ◽  
Vol 8 (S300) ◽  
pp. 420-421
Author(s):  
Sonja Jejčič ◽  
Petr Heinzel ◽  
Maciej Zapiór ◽  
Miloslav Druckmüller ◽  
Stanislav Gunár ◽  
...  
Keyword(s):  
Visible Light ◽  
Electron Density ◽  
Solar Eclipse ◽  
Light Emission ◽  
Total Solar Eclipse ◽  
Quiescent Prominence ◽  
Plasma Parameters ◽  
Eclipse Observations ◽  
First Time ◽  
Visible Light Emission

AbstractUsing the eclipse observations, we construct the maps of quiescent prominence temperatures, electron densities, pressures and geometrical thicknesses. For this we use the RGB signal of prominence visible-light emission detected during the total solar eclipse on August 1, 2008 in Mongolia, and quasi-simultaneous Hα spectra taken at Ondřejov observatory. The method of disentangling the electron density and effective geometrical thickness was described by Jejčič & Heinzel (2009) and is used here for the first time to analyse the spatial variations of various prominence parameters.

Total electron density from thes-electron density

1998 ◽  
Vol 57 (5) ◽  
pp. 3458-3461 ◽  
Author(s):  
Á. Nagy ◽  
E. Bene
Keyword(s):  
Electron Density ◽  
Total Electron Density ◽  
Total Electron
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