Sanaz Vahidinia, Sarah E. Moran, Mark S. Marley, Jeffrey N. Cuzzi
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引用次数: 0
Abstract
Aerosol opacity has emerged as a critical factor controlling transmission and emission spectra. We provide a simple guideline for the effects of aerosol morphology on opacity and residence time in the atmosphere, as it pertains to transit observations, particularly those with flat spectra due to high altitude aerosols. This framework can be used for understanding complex cloud and haze particle properties before getting into detailed microphysical modeling. We consider high altitude aerosols to be composed of large fluffy particles that can have large residence times in the atmosphere and influence the deposition of stellar flux and/or the emergence of thermal emission in a different way than compact droplet particles, as generally modeled to date for extrasolar planetary atmospheres. We demonstrate the important influence of aggregate particle porosity and composition on the extent of the wavelength independent regime. We also consider how such fluffy particles reach such high altitudes and conclude that the most likely scenario is their local production at high altitudes via UV bombardment and subsequent blanketing of the atmosphere, rather than some mechanism of lofting or transport from the lower atmosphere.
期刊介绍:
The Publications of the Astronomical Society of the Pacific (PASP), the technical journal of the Astronomical Society of the Pacific (ASP), has been published regularly since 1889, and is an integral part of the ASP''s mission to advance the science of astronomy and disseminate astronomical information. The journal provides an outlet for astronomical results of a scientific nature and serves to keep readers in touch with current astronomical research. It contains refereed research and instrumentation articles, invited and contributed reviews, tutorials, and dissertation summaries.