# What is diabatic convection?

Thermo-compositional diabatic convection is a new concept proposed in Tremblin et al. 2019 that encompass several well known convective systems in which source terms are important (thermohaline convection in Earth oceans, fingering convection in stars, moist convection in Earth atmosphere, steam/liquid water convection in cooling systems, and CO/CH$$_4$$ radiative convection in the atmosphere of brown dwarfs and extrasolar giant exoplanets).

Thermohaline convection in Earh oceans  (salt fingering regime Stern 1960)

• Composition is impacted by salt concentration
• The compositional source term is salt diffusion
• The thermal source term is thermal diffusion

Fingering convection in stellar interiors (Ulrich 1972)

• Composition is impacted by heavy elements concentration (e.g. iron)
• The compositional source term is the diffusion of heavy elements
• The thermal source term is thermal diffusion

Moist convection in Earth atmosphere (e.g. Von Bezold 1893)

• Composition is impacted by the concentration of water vapour
• The compositional source term is water condensation/evaporation
• The thermal source term is the pumping/release of latent heat

Steam/liquid water convection (assuming that the analysis can be extended to two-phase flows, e.g. cooling system of nuclear power plants)

• Composition is impacted by the concentration of water vapour
• The compositional source term is water condensation/evaporation
• The thermal source term is the pumping/release of latent heat

CO/CH4 radiative convection in the atmosphere of brown dwarfs and extrasolar giant exoplanets (Tremblin et al. 2016)

• Composition is impacted by the concentration of CH4 and CO
• The compositional source term is the chemical reactions converting CO into CH4
• The thermal source term is the radiative transfer impacted by CO and CH4 opacity