A new dust cycle model with dynamic vegetation: LPJ-dust version 1.0

摘要

This paper presents a new offline dust cycle model which uses theLund-Potsdam-Jena dynamic global vegetation model (Sitch et al., 2003) tocalculate time varying dust sources. Surface emissions are calculated bysimulating the processes of saltation and sandblasting using an existingmodel (Tegen et al., 2002). Dust particles are transported using the TOMCATchemical transport model (Chipperfield, 2006). Dust particles are removed from theatmosphere by dry deposition and sub-cloud scavenging. The model is designedso that it can be driven using reanalysis data or GCM derived fields.To improve the performance of the model, threshold values for vegetationcover, soil moisture, snow depth and threshold friction velocity, used todetermine surface emissions are tuned. The effectiveness of three sub-cloudscavenging schemes are also tested. An ensemble of tuning experiments areevaluated against dust deposition and surface concentration measurements.Surface emissions which produce the best agreement with observations rangefrom 1600 to 2400 Mtyr?1.