A one-dimensional sectional model to simulate multicomponent aerosol dynamics in the marine boundary layer 2. Model application

• Published in: Journal of Geophysical Research. D. Atmospheres Vol. 103; no. D13; pp. 16 - 117
• Main Authors: Fitzgerald, J W, Marti, J J, Hoppel, WA, Frick, G M, Gelbard, F
• Format: Journal Article
• Language: English
• Published: 01-07-1998
• Subjects: Marine; ANW, USA
• ISSN: 0148-0227

The dynamics of aerosols in the marine boundary layer (MBL) are simulated with the marine boundary layer aerosol model (MARBLES), a one-dimensional, multicomponent sectional aerosol model. First, to illustrate how the various aerosol processes influence the particle size distribution, the model was run with one or two processes operating on the same initial size distribution. Because of current interest in the effects of cloud processing of aerosols and exchange of aerosols with the free troposphere (FT) on marine aerosol size distributions, these two processes are examined in considerable detail. The simulations show that the effect of cloud processing (characteristic double-peaked size distribution) in the upper part of the MBL is manifested at the surface on a timescale that is much faster than changes due to exchange with the FT, assuming a typical exchange velocity of 0.6 cm s super(-1). The model predicts that the FT can be a significant source of particles for the MBL in the size range of the cloud-processing minimum, between the unactivated interstitial particles and the cloud condensation nuclei (CCN) which have grown as a result of conversion of dissolved SO sub(2) to sulfate in cloud droplets.