Internal-Gravity Waves Observed During the August 21, 2017 Total Solar Eclipse by National Eclipse Radiosonde Campaign

Abstract During a solar eclipse, the moon’s shadow progressively occults a part of Earth from the solar flux. This induces a cooling in the atmospheric layers that usually absorb the solar radiation. Since the eclipse shadow travels within the atmosphere at supersonic velocity, this cooling generates a planetary-scale bow wave of internal gravity waves. The purpose of this article is to estimate the surface atmospheric pressure fluctuations produced by the passage of the 1 August 2008 total solar eclipse and to compare these pressure fluctuations with those recorded by a temporary network of microbarographs and by the infrasound stations of the International Monitoring System. The surface pressure fluctuations expected at all the measurement sites are estimated using a linear spectral numerical model. It is shown that the cooling of both the ozonosphere and the troposphere can produce detectable pressure fluctuations at the ground surface but that the tropospheric cooling is likely to be the predominant source. Since the expected eclipse signals are in a frequency range that is highly perturbed by atmospheric tides and meteorological phenomena, the pressure fluctuations produced by these latter synoptic disturbances are characterized and removed from the recorded signals. Low-frequency gravity waves starting just after the passage of the eclipse are then brought to light at most measurement sites. The time–frequency characteristics of these waves are similar to those obtained from the model, which strongly suggests that these waves were produced by the passage of the 1 August 2008 solar eclipse.

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Atmospheric Gravity Wave Production for the Australian Total Solar Eclipse of 23 October 1976

Australian Journal of Physics ◽

10.1071/ph790287 ◽

1979 ◽

Vol 32 (3) ◽

pp. 287

Author(s):

SM Ball

Keyword(s):

Gravity Wave ◽

Western Australia ◽

Gravity Waves ◽

Solar Eclipse ◽

Internal Gravity Waves ◽

Total Solar Eclipse ◽

Atmospheric Gravity Wave ◽

Atmospheric Gravity

Calculations are presented which suggest that internal gravity waves generated by the 23 October 1976 total solar eclipse would have come to a focus in a region well north of Australia, and also in Antarctica. No evidence is found for a focus in Western Australia, as suggested by Beer et al. (1976).

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

Atmospheric Chemistry and Physics ◽

10.5194/acp-7-4943-2007 ◽

2007 ◽

Vol 7 (18) ◽

pp. 4943-4951 ◽

Cited By ~ 36

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.

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Atmospheric Gravity Waves Observed in the Nightglow Following the 21 August 2017 Total Solar Eclipse

Geophysical Research Letters ◽

10.1029/2020gl088924 ◽

2020 ◽

Vol 47 (17) ◽

Author(s):

I. Paulino ◽

C. A. O. B. Figueiredo ◽

F. S. Rodrigues ◽

R. A. Buriti ◽

C. M. Wrasse ◽

...

Keyword(s):

Gravity Waves ◽

Solar Eclipse ◽

Total Solar Eclipse ◽

Atmospheric Gravity Waves ◽

Atmospheric Gravity

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GPS‐TEC Observation of Gravity Waves Generated in the Ionosphere During 21 August 2017 Total Solar Eclipse

Journal of Geophysical Research Space Physics ◽

10.1002/2017ja024845 ◽

2018 ◽

Vol 123 (1) ◽

pp. 725-738 ◽

Cited By ~ 11

Author(s):

Chinmaya Nayak ◽

Erdal Yiğit

Keyword(s):

Gravity Waves ◽

Solar Eclipse ◽

Total Solar Eclipse ◽

Gps Tec

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

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-7-7603-2007 ◽

2007 ◽

Vol 7 (3) ◽

pp. 7603-7624 ◽

Cited By ~ 3

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.

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On the detection and attribution of gravity waves generated by the 20 March 2015 solar eclipse

Philosophical Transactions of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rsta.2015.0222 ◽

2016 ◽

Vol 374 (2077) ◽

pp. 20150222 ◽

Cited By ~ 9

Author(s):

G. J. Marlton ◽

P. D. Williams ◽

K. A. Nicoll

Keyword(s):

Gravity Waves ◽

Solar Eclipse ◽

Large Scale ◽

Sudden Change ◽

Weather Conditions ◽

Internal Gravity Waves ◽

Atmospheric Effects ◽

Detection And Attribution ◽

The Uk ◽

Atmospheric Gravity

Internal gravity waves are generated as adjustment radiation whenever a sudden change in forcing causes the atmosphere to depart from its large-scale balanced state. Such a forcing anomaly occurs during a solar eclipse, when the Moon’s shadow cools part of the Earth’s surface. The resulting atmospheric gravity waves are associated with pressure and temperature perturbations, which in principle are detectable both at the surface and aloft. In this study, surface pressure and temperature data from two UK sites at Reading and Lerwick are examined for eclipse-driven gravity wave perturbations during the 20 March 2015 solar eclipse over northwest Europe. Radiosonde wind data from the same two sites are also analysed using a moving parcel analysis method, to determine the periodicities of the waves aloft. On this occasion, the perturbations both at the surface and aloft are found not to be confidently attributable to eclipse-driven gravity waves. We conclude that the complex synoptic weather conditions over the UK at the time of this particular eclipse helped to mask any eclipse-driven gravity waves. This article is part of the themed issue ‘Atmospheric effects of solar eclipses stimulated by the 2015 UK eclipse’.

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