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

[摘要] This study aims at providing experimental evidence, to support thehypothesis according to which the movement of the moon's shadow sweeping theozone layer at supersonic speed, during a solar eclipse, creates gravitywaves in the atmosphere. An experiment was conducted to study eclipseinduced thermal fluctuations in the ozone layer (via measurements of totalozone 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, duringand after the total solar eclipse of 29 March 2006. We found the existenceof eclipse induced dominant oscillations in the parameters related to theozone layer and the ionosphere, with periods ranging between 30–40 min.Cross-spectrum analyses resulted to statistically significant squarecoherences between the observed oscillations, strengthening thermalstratospheric ozone forcing as the main mechanism for GWs. Additionalsupport for a source below the ionosphere was provided by the amplitude ofthe oscillations in the ionospheric electron density, which increasedupwards from 160 to 220 km height. Even though similar oscillations wereshown in surface temperature and relative humidity data, no clear evidencefor tropospheric influence could be derived from this study, due to themodest amplitude of these waves and the manifold rationale inside theboundary layer.

[学科分类] 大气科学