Characterizing Earth in the Mid-Infrared from an Observer’s Perspective
Mettler & Konrad et al. (2023) | Poster Life in the Universe II 2023
We study a set of real disk-integrated MIR thermal emission spectra of Earth. We consider monthly flux averages for January and July as well as three viewing angles: North Pole, South Pole, and Equatorial Combined. We simulate observations of Earth with the Large Interferometer For Exoplanets (LIFE) using LIFEsim (Dannert et al. 2022), by putting Earth on a 1 AU orbit around a G2V star located 10 pc from the observer. We generate spectra for different combinations of noise (S/N = 10, 20) and spectral resolution (R = 50, 100). Retrievals on such Earth remote sensing data help us understand how exoplanet observations can be safely analyzed. By treating Earth as an exoplanet, we study how our characterization depends on the observed viewing angle or season. We also investigate if retrievals that use simple 1D forward models can correctly characterize atmospheres. Finally, we study how patchy clouds can affect our characterization.