Modeling exoplanet clouds with virga

The observed atmospheric spectrum of exoplanets and brown dwarfs depends critically on the presence and distribution of atmospheric condensates. We present an open-source method to predict the parameters that govern radiative transfer; namely the vertical profile of condensate mass and the particle size distributions in condensation clouds. This model is an extension of that derived by Ackerman and Marley (2001) and is founded upon the assumption of a balance between upward turbulent diffusion and downward sedimentation in horizontally uniform cloud decks. The relative simplicity of this model renders it useful for retrieval studies due to their rapidly attainable solutions and thus can be computed and compared to data within a manageable timeframe. The complete model has been released as an open-source Python package VIRGA. In this poster we discuss how the model works, the assumptions we make and the resulting cloud profiles, with particular emphasis on the qualitative implications of our choice of parameters. We also examine the limitations of the model, their ramifications and the future direction of VIRGA to improve the model’s capability.