Ocean signatures in the total flux and polarization spectra of Earth-like exoplanets

ontext. Numerical simulations of starlight that is reflected by Earth-like exoplanets predict habitability signatures that can be searched for with future telescopes.<br/><br/>Aims. We explore signatures of water oceans in the flux and polarization spectra of this reflected light.<br/><br/>Methods. With an adding-doubling algorithm, we computed...

Sticky Snow: Combining Snow and Radiative Transfer Models in the Percolation Area of the Greenland Ice Sheet

Subsurface firn processes play a crucial role in ice sheet mass loss mechanisms. On Greenland surface meltwater percolates to deeper layers where porous firn retains it, directly inhibiting runoff. However, secondary effects such as the formation of impermeable ice slabs may indirectly and irreversibly accelerate runoff and with it global sea...

Multiphysics modelling of photon, mass and heat transfer in coral microenvironments

Coral reefs are constructed by calcifying coral animals that engage in a symbiosis with dinoflagellate microalgae harboured in their tissue. The symbiosis takes place in the presence of steep and dynamic gradients of light, temperature and chemical species that are affected by the structural and optical properties of the coral and their...

Modelling polarization and flux surface observations of Martian mesospheric CO2 ice clouds during twilight

Martian mesospheric CO2 ice clouds are formed out of the main constituent of the Martian atmosphere: CO2 gas. The nature of these clouds is poorly understood, characterization of these clouds in terms of particle morphology would give valuable insight into the Martian climate. So far, these CO2 clouds have only been detected from space. In this...

Colors of an Earth-like exoplanet: Temporal flux and polarization signals of the Earth

Context. Understanding the total flux and polarization signals of Earth-like planets and their spectral and temporal variability is essential for the future characterization of such exoplanets. Aims. We provide computed total (F) and linearly (Q and U) and circularly (V) polarized fluxes, and the degree of polarization P of sunlight that is...

First ALMA Millimeter-wavelength Maps of Jupiter, with a Multiwavelength Study of Convection

We obtained the first maps of Jupiter at 1-3 mm wavelength with the Atacama Large Millimeter/Submillimeter Array (ALMA) on 2017 January 3-5, just days after an energetic eruption at 16.5S jovigraphic latitude had been reported by the amateur community, and about two to three months after the detection of similarly energetic eruptions in the...

Transfer of Polarized Light in an (Exo)planetary Atmosphere-Ocean System

Fresnel reflection of starlight in the oceans of exoplanets results in two main phenomena: (1) a glint in the exoplanetary ocean, whose size increases with wind speed, and (2) a maximum degree of polarization at the Brewster angle. The corresponding features in the planetary phase curve, i.e. the flux and degree of polarization of the reflected...

Circular polarization signals of cloudy (exo)planets

The circular polarization of light that planets reflect is often neglected because it is very small compared to the linear polarization. It could, however, provide information on a planet’s atmosphere and surface, and on the presence of life, because homochiral molecules that are the building blocks of life on Earth are known to reflect...

Coupled magnetogasdynamics: Radiative transfer computing using unstructured meshes

We present a new object-oriented radiative-magnetogasdynamics (RMHD) code based on unstructured grid technology which is expected to be a convenient tool for investigations of plasma dynamics in various pulsed-power facilities. High-performance computing is a proper tool for simulations of complex multiscale nonlinear processes like transient...