Luo2023

Air refreshing limitation on wet scavenging from Luo & Yu (2023), Eqs. 2, 5, 10, 11. The air refreshing limited removal rate R_A accounts for the finite time needed for species in subgrid cloud-free (rain-free) air to mix into cloudy (rainy) air before being subject to wet scavenging; the standard well-mixed assumption overestimates wet scavenging when the subgrid air mixing time scale is comparable to the model time step. When turbulent mixing is strong (large TKE) the grid refreshing time goes to zero and R_A approaches f*Rᵢ (the standard model); when mixing is weak R_A falls below f*Rᵢ. Migrated from AtmosphericDeposition.jl@e4468c79 src/luo2023.jl:210 (`AirRefreshingLimitation` @component). Observed-only algebraic system: cloud fraction f, in-cloud removal rate Rᵢ, turbulence kinetic energy TKE, and the grid spacings Δx/Δy/Δz are input parameters; Kᵢ, τ_A, and R_A are the algebraic outputs fixed by three explicit equations.

Cloud ice uptake limitation on cold-cloud wet scavenging from Luo & Yu (2023), Eqs. 12-15. In cold clouds, water-soluble aerosols are captured by ice crystals via coagulation and then removed by precipitation; this component computes the cold-cloud rainout efficiency F_I from ice-crystal properties, turbulence, grid geometry, and temperature. The cloud ice uptake rate R_U is approximated by the HNO3 uptake rate of Jacob (2000) (Eq. 14); the temperature-dependent uptake efficiency gamma follows Hudson et al. (2002) (Eq. 15: gamma = 0.003 at T >= 220 K rising linearly to 0.007 at T <= 209 K); the cloudy-air refreshing rate Ki comes from turbulence kinetic energy and grid spacing (Eq. 11); the air-refreshing limited uptake rate R_AU applies the Eq. 2 refreshing-limit structure to R_U (Eq. 13); and F_I = 1 - exp(-R_AU*dt) (Eq. 12). Migrated from AtmosphericDeposition.jl@e4468c79 src/luo2023.jl:260 (`CloudIceUptakeLimitation` @component). Observed-only: the 5 equations are algebraic, so gamma, R_U, Ki, R_AU, F_I are the algebraic outputs while the 12 ice/turbulence/grid inputs and 9 module constants are parameters.

Combined air refreshing and cloud ice uptake limitations on wet scavenging from Luo & Yu (2023). This component unifies the two novel parameterizations of the paper into a single algebraic system: (1) the air refreshing limitation (Section 2.1, Eqs. 2/5/10/11), which reduces the wet-scavenging removal rate R_A when subgrid cloud-free (rain-free) air mixes into cloudy (rainy) air slower than the model time step; and (2) the cloud ice uptake limitation (Section 2.2, Eqs. 12-15), which limits the cold-cloud rainout efficiency F_I by the rate R_U at which water-soluble aerosols are captured by ice crystals -- the HNO3 ice uptake rate of Jacob (2000), with the temperature-dependent uptake efficiency gamma of Hudson et al. (2002). Migrated from AtmosphericDeposition.jl@e4468c79 src/luo2023.jl:326 (`WetScavengingLimitations` @component). The upstream component is a flat MTK System that inlines the equations of both AirRefreshingLimitation and CloudIceUptakeLimitation -- it does not `couple` them -- so this migration is the union of air_refreshing.esm (esm-1i3m) and cloud_ice_uptake.esm (esm-3hh9): 13 input parameters, 9 module constants, and 7 algebraic state variables (Kᵢ, τ_A, R_A, gamma, R_U, R_AU, F_I) fixed by 7 explicit equations. Observed-only: every equation is algebraic, so the 7 outputs are the algebraic solution while the ice/turbulence/grid/temperature inputs and module constants are parameters.