Internal gravity-wave motions induced in the earth's atmosphere by a solar eclipse

Chimonas, G.

doi:10.1029/gm018p0708

Cited by 41 publications

(85 citation statements)

References 6 publications

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“…Anderson et al (1972) reported on surface pressure fluctuations in the range 15-150 min and Seykora et al (1985) found a surface pressure response with a period of about 4 h and a speed of 320 m s −1 . The amplitudes of these waves were larger than those predicted by Chimonas (1970), but agree well with the 0.1-0.5 hPa range modelled recently by Eckermann et al (2007).…”

Section: Introductionsupporting

confidence: 89%

“…The source of these waves was assumed to be either at higher altitudes e.g. at around 90 km where molecular oxygen heating begins (Chimonas, 1970), or at lower altitude e.g. water vapor IR absorption (Lamb waves) and the ground cooling (Chimonas and Hines, 1971;Chimonas, 1973).…”

Section: Introductionmentioning

confidence: 99%

“…water vapor IR absorption (Lamb waves) and the ground cooling (Chimonas and Hines, 1971;Chimonas, 1973). Morover, in both Chimonas (1970) and its subsequent follow on study of Firtts and Luo (1993), thermal cooling of the stratospheric ozone layer as the forcing function of GWs during a solar eclipse was considered. Eckermann et al (2007), with their high-altitude global numerical weather prediction model, recently simulated an induced radiative cooling rate in the stratosphere, 2-3 times larger than assumed in these earlier stratospheric bow wave models.…”

Section: Introductionmentioning

confidence: 99%

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

et al. 2007

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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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Section: Introductionsupporting

confidence: 89%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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

et al. 2007

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“…There are several investigations on the Earth's atmospheric and ionospheric effects of SEs [e.g., Boyd, 1966;Anderson et al, 1972;Antonia et al, 1979;Srivastava et al, 1982;Chimonas and Hines, 1970;Chimonas, 1970;Clilverd et al, 2001;Babakhanov et al, 2013 and references therein]. Further studies on SEs ionospheric effects (particularly in lower ionosphere) are warranted because of the fact that each eclipse is different from others based on the occurrence time of the year, time of the day, degree of the solar disk occultation, state of the space, and atmospheric weather and location (latitude and longitude) of observations on the Earth [Baran et al, 2003].…”

Section: Introductionmentioning

confidence: 99%

“…Apart from wide range of implications of SEs on the near Earth's atmosphere and ionosphere, the two most important consequences of SEs are ionospheric variability due to sudden cutoff of solar radiation for a short duration and generation of gravity waves (GWs) [Chimonas, 1970;Zerefos et al, 2007;Babakhanov et al, 2013]. The passage of solar terminator is another main in situ source of GWs.…”

Section: Introductionmentioning

confidence: 99%

Low‐mid latitude D region ionospheric perturbations associated with 22 July 2009 total solar eclipse: Wave‐like signatures inferred from VLF observations

Maurya¹,

Phanikumar

Singh³

et al. 2014

JGR Space Physics

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We present first report on the periodic wave-like signatures (WLS) in the D region ionosphere during 22 July 2009 total solar eclipse using JJI, Japan, very low frequency (VLF) navigational transmitter signal (22.2 kHz) observations at stations, Allahabad, Varanasi and Nainital in Indian Sector, Busan in Korea, and Suva in Fiji. The signal amplitude increased on 22 July by about 6 and 7 dB at Allahabad and Varanasi and decreased by about 2.7, 3.5, and 0.5 dB at Nainital, Busan, and Suva, respectively, as compared to 24 July 2009 (normal day). The increase/decrease in the amplitude can be understood in terms of modal interference at the sites of modes converted at the discontinuity created by the eclipse intercepting the different transmitter-receiver great circle paths. The wavelet analysis shows the presence of WLS of period~16-40 min at stations under total eclipse and of period~30-80 min at stations under partial eclipse (~85-54% totality) with delay times between~50 and 100 min at different stations. The intensity of WLS was maximum for paths in the partially eclipsed region and minimum in the fully eclipsed region. The features of WLS on eclipse day seem almost similar to WLS observed in the nighttime of normal days (e.g., 24 July 2009). The WLS could be generated by sudden cutoff of the photo-ionization creating nighttime like conditions in the D region ionosphere and solar eclipse induced gravity waves coming to ionosphere from below and above. The present observations shed additional light on the current understanding of gravity waves induced D region ionospheric perturbations.

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Gravity wave signatures in the dip equatorial ionosphere‐thermosphere system during the annular solar eclipse of 15 January 2010

et al. 2014

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The present work pertains to the eclipse-induced gravity wave modulations in the ionosphere-thermosphere region over Trivandrum (8.5°N, 77°E, dip 2°N) during the annular solar eclipse of 15 January 2010. Electron density and neutral wind rocket payload measured horizontal winds and electron densities at E region altitudes, and ionosonde-derived f o F 1 and f o F 2 parameters are used to analyze the characteristics of the eclipse-induced gravity waves. The analysis reveals an intensification of gravity waves with periods around 30-100 min during the peak phase of the eclipse. The vertical wavelength of the prevalent wave is found to be around 2 km. The role of gravity wave-induced winds in generating blanketing E s over the equator is also examined.

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Internal gravity-wave motions induced in the earth's atmosphere by a solar eclipse

Cited by 41 publications

References 6 publications

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

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

Low‐mid latitude D region ionospheric perturbations associated with 22 July 2009 total solar eclipse: Wave‐like signatures inferred from VLF observations

Gravity wave signatures in the dip equatorial ionosphere‐thermosphere system during the annular solar eclipse of 15 January 2010

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