Hi all,
I’m wondering how the WRF-CMAQ coupled model describes the change in particle size of aerosols when the relative humidity increases, especially for sea salt. Is there any corresponding growth factor or kappa value that describes the change in particle size? I noticed that the particle size of the sea salt during its emission is described discretely using a set of database from Gong 2008. Does it mean that the particle size of the sea salt does not change with RH?
Liu
CMAQ calculates aerosol liquid water using ISORROPIA II (Fountoukis et al. 2007) for inorganic species (including the Na and Cl in sea salt). For water uptake onto organic aerosol species, Kappa-Kohler theory is used as described by Pye et al. (2017). The size due to water uptake can be obtained as a function of the species mass, species density, and other properties of the size distribution. There are several parts of CMAQ where a dry vs wet size distribution can be obtained.