Emep

EMEP-formulation wet deposition model for PM2.5, SO2, and other gases. Computes three first-order wet deposition rate coefficients (k_particle, k_SO2, k_othergas [1/s]) from cloud fraction (cloudFrac), rain mixing ratio (qrain), air density (rho_air), and the atmospheric level index (lev). Subcloud scavenging rates scale as qrain*rho_air/Dz times a species-specific washout coefficient; in-cloud scavenging additionally scales with cloudFrac; the particle subcloud term uses A_wd*E*qrain*rho_air without the 1/Dz factor. The layer depth Dz is looked up from a 72-entry constant table (GEOS-Chem-derived model-level thicknesses in metres) indexed by lev. The gt-p3ep blocking gap (get_lev_depth is @register_symbolic) is resolved by expressing the lookup as an interp.linear AST composition over the 72-entry integer-axis table — matching the FastJX_interpolation_troposphere precedent. Migrated from AtmosphericDeposition.jl@e4468c79 src/wet_deposition.jl:147 (the WetDeposition builder) and src/wet_deposition.jl:82 (_WetDeposition helper). Purely algebraic: no differential states; k_particle, k_SO2, k_othergas are observed variables.