Exoclimes Simulation Platform
The Exoclimes Simulation Platform (ESP) was born from a necessity to move beyond Earth-centric approaches to understanding atmospheres. Our dream and vision is to provide the exoplanet community with an open-source, freely-available, ultra-fast and cutting-edge set of simulational tools for studying exoplanetary atmospheres. The ESP harnesses the power of GPUs (graphic processing units), found in most Macs nowadays, to produce speed-ups at the order-of-magnitude level. These speed-ups are invested in building intuition and studying how atmospheric dynamics, chemistry and radiation interact in various ways. Our ultimate goal is for users to become co-developers. The ESP team is committed to quality, precision and transparency at the highest level.
Exoclimes Simulation Platform posts
A first version of HELIOS is released and available for download in the "Source Code" section, which provides a link to the GitHub repository. The corresponding publication describing the method and first applications of the code can be found on arXiv (see "Links" section).
Shami Tsai has successfully benchmarked the analytical chemistry formula derived in Heng, Lyons & Tsai (2016) and Heng & Lyons (2016) against the TEA code, which computes equilibrium chemistry via Gibbs free energy minimization. This has major implications for calculations of atmospheric retrieval, because of the tremendous speed-up associated with using the analytical formula.
Efficient parallel computations in THOR require global domain decomposition of the grid. In our model we take the advantage of the geometrical properties of the icosahedron which can be divided into 10 rhombuses as shown in the figure. The rhombuses can be then easily divided into smaller sub-domains (smaller rhombuses) which are essential to optimize the simulations.
THOR solves the deep-atmosphere non-hydrostatic Euler equations. The figure shows the averaged zonal wind obtained from the Earth benchmark test proposed in Held and Suarez 1994. The new model passed the test successfully.
This animation shows the temperature evolution at the surface obtained with our new dynamical core THOR. The physical schemes and parameters used in the model are from the Held-Suarez benchmark test (Held & Suarez 1994).
Kevin and Jim just submitted a paper to the Astrophysical Journal, which presented a novel analytical solution for systems in chemical equilibrium that include carbon dioxide, carbon monoxide, water, methane and acetylene. They used this solution, alongside analytical solutions of temperature-pressure profiles, to show that carbon dioxide is almost always the minor species compared to carbon monoxide and water. They further explored how atmospheric mixing (it does not) and metallicity (requires temperatures hotter than 1000 K and extreme enhancements) affect this conclusion. This implies that previously reported retrievals by Madhusudhan et al. (2011) and Line et al. (2014) are chemically impossible.
Real-time 1D radiative transfer computation with the code HELIOS. We start with an isothermal atmosphere and iterate for the temperature until radiative equilibrium in all the atmospheric layers is established. Here, we model the Super-Earth GJ1214b. The stellar irradiation is averaged over the day-hemisphere.
Our method paper on HELIOS-K (Grimm & Heng 2015) has been accepted by the Astrophysical Journal for publication.
Kevin, Jim and Shami just submitted a paper on the theoretical foundations of atmospheric chemistry to the Astrophysical Journal. It unifies the various key quantities and their derivations under a single, common umbrella. It also provides easy-to-use analytical models for molecular abundances vs. carbon-to-oxygen ratio. The formalism sets the stage for the first version of VULCAN.