ORILAM is a three-moment lognormal aerosol scheme. It has been developed by the Laboratoire d'Aérologie (UMR 5560 UPS/CNRS) and by CNRM-GAME (UMR 3589 CNRS/Météo-France) in the Meso-NH model, but can be coupled in other three-dimensional mesoscale or CTM models. It represents a broad range of aerosol processes such as nucleation, coagulation, condensation, sedimentation, and dry deposition. One particular interest of ORILAM is to keep explicit the aerosol composition and distribution (mass of each constituent, mean radius, and standard deviation of the distribution are explicit) using the prediction of three-moment (m0, m3, and m6).
It also includes ORILAM-SOA which is an extension of the lognormal aerosol dynamics model ORILAM. ORILAM-SOA consists of the original aerosol dynamics routines, a photochemical scheme able to predict SOA precursors, and an equilibrium scheme able to predict partitioning of the precursors between the gas and aerosol phases.

References are :
- Tulet, P., V. Crassier, F. Cousin, K. Suhre, and R. Rosset, ORILAM, a three-moment lognormal aerosol scheme for mesoscale atmospheric model: Online coupling into the Meso-NH-C model and validation on the Escompte campaign, J. Geophys. Res., 110, D18201, doi:10.1029/2004JD005716, 2005.
- Tulet, P., A. Grini, R. J. Griffin, and S. Petitcol, ORILAM-SOA: A computationally efficient model for predicting secondary organic aerosols in three-dimensional atmospheric models, J. Geophys. Res., 111, D23208, doi:10.1029/2006JD007152, 2006.