The boundary layer model MISTRA

The microphysical marine boundary layer model MISTRA was originally a microphysical model only (Bott et al., 1996) but later expanded to include gas. aerosol and cloud droplet chemistry (von Glasow et al., 2002a,b). Apart from a description of the dynamics and thermodynamics it includes a detailed microphysical module that calculates particle growth explicitly and treats feedbacks between radiation and particles.
Chemical reactions in the gas phase are considered in all model layers, aerosol chemistry only in layers where the relative humidity is greater than the crystallization humidity. When a cloud forms, cloud droplet chemistry is also active. Fluxes of heat, moisture, sea salt aerosol particles and gases from the ocean are included. The set of chemical reactions is solved using KPP. The Figure below shows schematically the most important processes that are included in the model for a cloud covered MBL. A detailed model description and evaluation can be found in von Glasow et al., 2002a,b.



The complete set of gas, heterogeneous and aqueous phase reactions as well as Henry and equilibrium constant can be downloaded as PDF files: Kinetic data

Recent model developments include:

• Extension of sulphur chemistry (von Glasow and Crutzen, 2004).
• Description of OIO-induced new particle formation (Pechtl et al., 2006).
• Extension to simulate the plumes of passively degassing volcanoes (Bobrowski et al., 2007; Aiuppa et al., 2007, von Glasow, 2010)
• Improved description of aqueous phase in general and iodine aqueous phase in particular (Pechtl et al., 2007).
• Inclusion of mercury chemistry (von Glasow, 2010).
• Development of improved iodine gas phase chemical reaction mechanism (Sommariva et al., 2012).