USE OF A NEW DATABASE OF LEAD-210 FOR GLOBAL AEROSOL MODEL VALIDATION

The new comprehensive global database of Pb-210 surface concentration and deposition flux assembled by Preiss et al. [1996a] is synthesized by reduction and aggregation on a 5 degrees x5 degrees grid to facilit ate and improve the analysis of a general circulation model-based aero sol and climate model, The model is found to generally underestimate s urface concentrations, and to overestimate (underestimate) deposition fluxes over source (non source) regions (respectively), We think that the simulated precipitation scavenging of aerosols is too efficient in the lower part of the troposphere, and too weak in the higher levels. This would be consistent with the spatial distribution of concentrati on and deposition errors in the model, and is backed up by the few ava ilable observed vertical profiles of Pb-210 concentration. This paper demonstrates the usefulness, appropriateness and convenience for aeros ol model validation of the synthesized Pb-210 database, which is liste d in detail for use by other modelers.