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

Abstract

[1] Classical aerosol schemes use either a sectional (bin) or lognormal approach. Both approaches have particular capabilities and interests: the sectional approach is able to describe every kind of distribution, whereas the lognormal one makes assumption of the distribution form with a fewer number of explicit variables. For this last reason we developed a three-moment lognormal aerosol scheme named ORILAM to be coupled in three-dimensional mesoscale or CTM models. This paper presents the concept and hypothesis of a 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 threemoment (m0, m3, and m6). The new model was evaluated by comparing simulations to measurements from the Escompte campaign and to a previously published aerosol model. The numerical cost of the lognormal mode is lower than two bins of the sectional one.Citation: Tulet, P., V. Crassier, F. Cousin, K. Suhre, and R. Rosset (2005), 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.

Online coupled regional meteorology chemistry models in Europe: current status and prospects

“…For performance reasons, the simulations were carried out with a strongly reduced chemical scheme but satisfactorily depicted the location and spatial extent of the pollution plume of Paris and elevated O 3 levels downwind of the city. The modelling system was described in more detail in Tulet et al (2003) and compared with O 3 observations in France for a simulation period in August 1997. It was extended with the sectional aerosol model ORISAM (Cousin et al, 2004) as well as with the three-moments aerosol scheme ORILAM for the simulation of aerosol dynamics and secondary inorganic and organic aerosols (Tulet et al, 2005), which laid the foundation for studies of chemistrymeteorology feedbacks.…”

“…modes), mineral (nuc./ acc./ coa. modes), mineral (transported), sulfate droplets C: Grid and sub-grid scale bulk G: None A: Only through temperature change caused by LW/SW C: Grid and sub-grid scale bulk SW, LW, PH: Model time step GEM Kaminski et al (2008) Correlated K (Li and Barker, 2005) with O3, H2O and aerosols from chemistry Correlated K (Li and Barker, 2005) with O3, H2O and aerosols from chemistry G,A,C all taken into account in Jvalue calculations using method of Landgraf and Crutzen, 1998 SW, LW, PH: model time step Lafore et al (1998) G: Climatology for O3 (Fortuin and Langematz, 1994), constant background for CO2, CH4, N2O, CFC11,CFC12 A: With prognostic aerosol (Tulet et al, 2005) , radiative properties of aerosols according to Mie theory (Aouizerats et al, 2010). Without aerosol scheme, climatological aerosols.…”

Long‐range transport of Saharan dust and its radiative impact on precipitation forecast: a case study during the Convective and Orographically‐induced Precipitation Study (COPS)

“…In this parametrization, the three log-normal modes are generated and transported by the log-normal aerosol scheme of the ORganic and Inorganic Log-normal Aerosols Model (ORILAM: Tulet et al, 2005). These modes are described by their zeroth, third and sixth moments, with the latter kept constant.…”

Dust impact on the West African heat low in summertime

“…The dust prognostic scheme is described in Grini et al (2006). In this parametrization, the three log-normal modes were generated and transported by the log-normal aerosol scheme of the ORganic and Inorganic Log-normal Aerosols Model (ORILAM: Tulet et al, 2005). These modes were described by their zeroth, third and sixth moments, with the last kept constant.…”