1. Retrievals of Dayside Emission Spectra: Trends in Chemistry Michael Line, Aaron Wolf, Xi Zhang, Yuk Yung Caltech

2. Thermo. Eq. Vertically Mixed Photochemistry Ions CO CH 4 CO quenched CH 4 quenched

3. H 2 O + CH 4 = CO + 3H 2

4. Synthetic Study S/N~3.5 Δλ=0.0075 μm Spitzer Broadband Spitzer Broadband+IRS+NICMOS FINESSE

5. MCMC Optimal Est.

6. HD189733 Moses et al. 2011 WASP12 Kopparapu et al. 2012 GJ436 Line et al. 2011

7. GJ436 HD189733 TRES2 HD149026 WASP19 WASP12 HD189733 Moses et al. 2011 WASP12 Kopparapu et al. 2012 GJ436 Line et al. 2011

8. GJ436 HD189733 TRES2 HD149026 WASP19 WASP12 MCMC OPT. EST. Dis-eq. Models HD189733 Moses et al. 2011 WASP12 Kopparapu et al. 2012 GJ436 Line et al. 2011

9. Conclusions Opt est and MCMC agree for “quality” data Most planets seem out of equilibrium (to within “1- sigma”) Errors large on current gas estimations Need dedicated space based spectroscopic instrument Can maybe constrain K zz

10. Goals Look at the ensemble of planetary atmospheres. Indentify trends in composition—equilibrium vs. disequilibrium First must robustly determine temperatures and compositions of exoplanet atmosphere

11. Two Bayesian Retrieval Approaches Optimal Estimation (Lee et al. 2011, Line et al. 2012) This Parameter That Parameter -Levenberg-Marquardt to find best solution -Assumes Gaussian posterior - Fast—not slowed down by additional parameters or more sophisticated forward models This Parameter That Parameter - Randomly explore’s all of parameter space - Accounts for non-Gaussian posteriors - Slow—many parameters and more sophisticated forward models unwieldy Markov Chain Monte Carlo (Madhusudhan et al. 2011, Benneke & Seager 2012) Forward Model: [T, f H2O, f CH4, f CO, f CO2 ] Guillot 2010 [γ v1, γ v2, κ IR, α, β]

12. Synthetic Study Spitzer Broadband Spitzer Broadband+IRS+NICMOS FINESSE MCMC Opt. Est. True

13. Synthetic Study Spitzer Broadband Spitzer Broadband+IRS+NICMOS FINESSE