Radiation

ClimaAtmos computes radiative fluxes with RRTMGP.jl, a GPU-capable Julia implementation of the RRTMGP correlated k-distribution model, wrapped in src/parameterized_tendencies/radiation/RRTMGPInterface.jl. The radiative flux divergence enters the total energy equation as an explicit tendency (see the governing equations), updated by a radiation callback at the cadence set by dt_rad (default 6hours).

Under construction

A full explanation page (the RRTMGP coupling, cloud and aerosol optics, and the insolation models) is planned. The overview below is current.

Radiation modes

The rad configuration argument selects the mode:

gray: gray radiation, an idealized one-band model.
clearsky: RRTMGP with gases but no cloud optics.
allsky: RRTMGP with interactive cloud optics.
allskywithclear: as allsky, plus clear-sky diagnostic fluxes.
held_suarez: the Held–Suarez temperature relaxation (no radiative transfer; applied every stage), plus idealized single-column forcings (DYCOMS, TRMM_LBA, ISDAC).

Clouds enter the all-sky modes either interactively from the model state or prescribed from ERA5 data (prescribe_clouds_in_radiation). Trace-gas concentrations are described on the Trace Gases page, and the insolation at the top of the atmosphere is computed by Insolation.jl (see The CliMA Ecosystem). The ocean surface albedo models are described on the Ocean Surface Albedo page.