Atmosphere ⇒ Coupler

• wind, temperature and humidity of lowest atmospheric model level: used in calculation of surface wind stress and turbulent heat fluxes
• solar radiation
• downward long-wave flux (thermal radiation from atmosphere and clouds)
• precipitation (rain and snow)
• CO₂ concentration
• aerosol deposition

Coupler ⇒ Atmosphere

• turbulent heat fluxes (sensible and latent)
• evapo(transpi)ration (this is linearly related to the latent heat flux as the latent heat flux is simply the energy needed to evaporate the water)
• momentum fluxes (=surface wind stress)
• surface albedo (i.e., brightness/reflectivity): used to compute how much sun-light is reflected
• longwave (i.e., thermal) radiation from surface (function of surface temperature)
• CO₂ flux from land and ocean
• aerosol flux from land and ocean (sea salt, DMS, dust, black carbon and others)

Ocean ⇒ Coupler

• SST – used in computation of sensible and latent heat fluxes between atmos and ocean and in computation of sea-ice melt/growth
• SSS – used in computation of sea ice growth/melt
• Surface currents – used in computation of surface wind stress
• Ocean – atmospheric CO₂ flux – used in computation of atmos CO₂ conc
• Ocean – atmospheric DMS (organic particle) flux – used in cloud formation

Coupler ⇒ Ocean

• Sensible and latent (=turbulent) heat fluxes
• Radiative heat fluxes – short wave (solar) and long wave (thermal)
• Freshwater fluxes – precipitation, runoff (liquid and frozen), evaporation
• Momentum fluxes (=wind stree at surface)
• Atmospheric CO₂ concentration, 10 m wind and sea ice concencration – used in calculation of surface CO₂ flux

Sea ice ⇒ Coupler

• (skin-)surface temperature
• surface albedo (depends on ice concentration and snow conditions)
• momentum flux (ice-atmosphere and ice-ocean)
• heat, salt and water fluxes due to freezing/melting of sea ice

Coupler ⇒ Sea ice

• temperature, humidity and wind at lowest atmospheric level: used to calculate sensible+latent heat fluxes and evaporation
• short-wave (solar) and long-wave (thermal) radition from atmosphere/clouds
• SST and SSS: used to calculate ice growth/melt
• precipitation (rain and snow)
• dust deposition: changes reflectivity of ice/snow

Note: in NorESM, heat, freshwater and momentum fluxes over sea-ice are calculated inside the sea ice component  and then passed to the coupler

Land ⇒ Coupler

• surface albedo
• long-wave radiation from surface (computed from surface temperature and surface type)
• surface wind-stress
• sensible and latent heat flux + evaporation
• land runoff: passed to river routing
• surface CO₂ flux

River routing ⇒ Coupler

• ocean runoff (liquid and frozen)

Note: in NorESM, heat, freshwater and momentum fluxes over land are calculated inside the land component and then passed to the coupler

Coupler ⇒ Land

• short-wave (solar) and long-wave (thermal) radiation from atmosphere/clouds
• wind, temperature and humidity of lowest atmospheric model level: used to calculated sensible+latent heat fluxes and evaporation
• precipitation (rain and snow)
• atmospheric CO₂

Coupler ⇒ River routing

• land runoff (liquid and frozen)