Detalles de publicación

PP 011031

The impact of the Kasatochi eruption on the Moons illumination during the August 2008 lunar eclipse

A. Garcia Munoz (1,2) E. Palle (1,2) M.R. Zapatero Osorio (3) and E.L. Martin (3)
(1) Instituto de Astrofisica de Canarias (IAC), C/ Via Lactea s/n, E-38200 La Laguna, Tenerife, Spain (2) Departamento de Astrofisica, Universidad de La Laguna (ULL), E-38206 La Laguna, Tenerife, Spain (3) Centro de Astrobiologia, CSIC-INTA,
The Moons 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 Earths shadow. The contribution to the Moons aspect from sunlight scattered at the Earths 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 spectrums 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.

 
Aceptado para publicación en GEOPHYSICAL RESEARCH LETTERS | Enviado el 2011-06-15 | Proyecto 3I0308