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Climate

Planets are complex systems, and the thermal structure of a planet’s atmosphere is determined by interactions between a number of physical processes (e.g., radiative transfer, convection, advection).  To date, though, even the best observations of exoplanets have only yielded a handful of spectral data points for a small handful of objects.  The implication is that complex models of exoplanet atmospheric circulation and thermal structure are extremely under-constrained when used to interpret these sparse observations.  To help enable the interpretation of exoplanet observations, I developed the simplest possible atmospheric thermal structure model that is both general and realistic (Robinson & Catling 2012).  Using only a small handful of parameters (6-10), this analytic model generates a one-dimensional average temperature-pressure profile for a planetary atmosphere in radiative-convective equilibrium.

An implementation of the analytic model can be found here.  There are three pieces of code: (1) AN_RC_MOD.pro is the workhorse which solves for the radiative-convective boundary when given the appropriate input, (2) EXAMPLE.pro demonstrates a use of AN_RC_MOD.pro to generate a pressure-temperature profile for Titan, and (3) EXAMPLE_W_FLUXES.pro is similar to the other example, but adds the calculation of the relevant fluxes.  The headers contain more info, and EXAMPLE_W_FLUXES uses a piece of IDL code called INTEGRAL.pro.  Please let me know if you run into any problems when using AN_RC_MOD.pro, if you find any bugs, or make any cool improvements.  Also, please cite the aforementioned paper if you use this tool in your own work.




Example outputs from the analytic radiative-convective model as applied to Titan. Top-left shows a pressure-temperature profile, top-right shows a profile of net solar flux, bottom-left shows profiles of upwelling (right) and downwelling (left) thermal flux, and bottom-left shows a profile of convective flux (note the different vertical-axis scale).