Open AccessDust and cloud detection at the Mars limb with UV scattered sunlight with SPICAM
Author(s) -
Rannou P.,
Perrier S.,
Bertaux J.L.,
Montmessin F.,
Korablev O.,
Rébérac A.
Publication year - 2006
Publication title -
journal of geophysical research: planets
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2006je002693
Subject(s) - mars exploration program , atmosphere (unit) , atmosphere of mars , haze , sunlight , particle (ecology) , astrobiology , radiative transfer , range (aeronautics) , atmospheric sciences , physics , interplanetary dust cloud , environmental science , materials science , astronomy , optics , geology , solar system , meteorology , martian , oceanography , composite material
The UV detector of Spectroscopy for the Investigation of the Characteristics of the Atmosphere of Mars (SPICAM) on board Mars Express has measured several profiles of light scattered at the limb of Mars. In this paper we present 33 profiles taken between January 2004 and August 2005. Scattering of UV light at the limb of Mars is due to the molecules of the atmosphere, dust particles, and sometimes cloud particles which appear as detached layers above the extended dust layer. We have used a radiative transfer model to retrieve the haze and cloud properties. Rough estimate of the particle size shows that both cloud particles and dust particles above 20 km are in the range 10 to 100 nm. Such particles are much smaller than micron‐sized dust particles previously observed in the lower atmosphere, generally from landers. Gravitational segregation is thought to be responsible for these differences in particle size between low and high atmosphere.