The impact of the Kasatochi eruption on the Moon's illumination during the August 2008 lunar eclipse

García Muñoz, A.; Pallé, E.; Zapatero Osorio, M. R.; Martín, E. L.
Bibliographical reference

Geophysical Research Letters, Volume 38, Issue 14, CiteID L14805

Advertised on:
7
2011
Number of authors
4
IAC number of authors
2
Citations
15
Refereed citations
12
Description
The Moon's changeable aspect during a lunar eclipse is largely attributable to variations in the refracted unscattered sunlight absorbed by the terrestrial atmosphere that occur as the satellite crosses the Earth's shadow. The contribution to the Moon's aspect from sunlight scattered at the Earth's terminator is generally deemed minor. However, our analysis of a published spectrum of the 16 August 2008 lunar eclipse shows that diffuse sunlight is a major component of the measured spectrum at wavelengths shorter than 600 nm. The conclusion is supported by two distinct features, namely the spectrum's tail at short wavelengths and the unequal absorption by an oxygen collisional complex at two nearby bands. Our findings are consistent with the presence of the volcanic cloud reported at high northern latitudes following the 7-8 August 2008 eruption in Alaska of the Kasatochi volcano. The cloud both attenuates the unscattered sunlight and enhances moderately the scattered component, thus modifying the contrast between the two contributions.
Type