A Database of Geometric Albedo Spectra for Rocky Exoplanets

Here we present a database of albedo spectra for rocky, Earth-sized and Earth-mass exoplanets, as computed with the NASA Planetary Spectrum Generator tool (psg.gsfc.nasa.gov; Villanueva et al. 2018). The database is presented in two Python .pickle files containing pandas DataFrame objects. The DataFrame index values are wavelength, in micrometers; while the column name values contain the encoded parameters represented in the model object's albedo spectra contained with in that column. Each cell then gives the calculated geometric albedo value for the column-named model planet at the row-indicated wavelength.

Two files are presented. One contains models with clouds; one contains models without clouds. 

To decode the column names, using a Python string.format function. For cloudy models, the format is:

ColName='{}{}H2{}_R1.0g9.8P{}A{}r10l{}ct{}f0.1'.format(Cdom,Cmix,H2mix,P0,As,Mcld,Ctop)

For cloud-free models, the final two parameters are not used. Thus, the correct format is:

ColName='{}{}H2{}_R1.0g9.8P{}A{}'.format(Cdom,Cmix,H2mix,P0,As)

Here, the parameters are as follows:

Cdom: The name of the dominant absorbing chemical in the atmosphere. Accepted values are H2O, CH4, CO2, SO2, and O2.

Cmix: The log₁₀ of the mixing value of the dominant chemical in the atmosphere. Accepted values are [-7.0,-6.0,-5.0,-4.0,-3.0,-2.0,-1.0,-0.01].

H2mix: The mixing ratio of molecular hydrogen in the (otherwise) N2 background gas. Expressed as H2/(H2+N2). Accepted values are [0.0,0.02,0.05,0.15,0.5].

P0: The surface pressure of the planet, in log₁₀(bars). Accepted values are [-1.0,-0.5,0.0,0.5,1.0,1.5,2.0]

As: The grey, geometric albedo value of the surface of the planet. Accepted values are [0.05,0.2,0.35,0.5]

Mcld: The linear cloud mass of cloud matter in the atmosphere, in log₁₀(kg/m^2). Accepted values are [-3.0,-2.5,-2.0,-1.5,-1.0].

Ctop: The pressure at the top layer of the clouds. Acceptable values are [-2.0,-1.5,-1.0,-0.5,0.0,0.5,1.0]. Note that Ctop<P0 for all models.

Thus, an atmosphere with a pure N2 background gas and a 0.3% H₂O mixing ratio, with 1 bar of surface pressure, 0.05 surface albedo, and 1 gram of cloud matter topping at 0.316 bars altitude would be named:

H2O-3.0H20.0_R1.0g9.8P0.0A0.05r10l-3.0ct-0.5f0.1

The database is described in Smith et al. (in review).