Status: this preprint was under review for the journal BG but the revision was not accepted.
Reviews and syntheses: Weathering of silicate minerals in soils and watersheds: Parameterization of the weathering kinetics module in the PROFILE and ForSAFE models
Harald Ulrik Sverdrup,Eric Oelkers,Martin Erlandsson Lampa,Salim Belyazid,Daniel Kurz,and Cecilia Akselsson
Abstract. The PROFILE model, now incorporated in the ForSAFE model can accurately reproduce the chemical and mineralogical evolution of the soil unsaturated zone. However, in deeper soil layers and in groundwater systems, it appears to overestimate weathering rates. This overestimation has been corrected by improving the kinetic expression describing mineral dissolution by adding or upgrading breaking functions. The base cation and aluminium brakes have been strengthened, and an additional silicate brake has been developed, improving the ability to describe mineral-water reactions in deeper soils. These brakes are developed from a molecular-level model of the dissolution mechanisms. Equations, parameters and constants describing mineral dissolution kinetics have now been obtained for 102 different minerals from 12 major structural groups, comprising all types of minerals encountered in most soils. The PROFILE and ForSAFE weathering sub-model was extended to cover two-dimensional catchments, both in the vertical and the horizontal direction, including the hydrology. Comparisons between this improved model and field observations is available in Erlandsson Lampa et al. (2019, This special issue). The results showed that the incorporation of a braking effect of silica concentrations was necessary and helps obtain more accurate descriptions of soil evolution rates at greater depths and within the saturated zone.
How to cite. Sverdrup, H. U., Oelkers, E., Erlandsson Lampa, M., Belyazid, S., Kurz, D., and Akselsson, C.: Reviews and syntheses: Weathering of silicate minerals in soils and watersheds: Parameterization of the weathering kinetics module in the PROFILE and ForSAFE models, Biogeosciences Discuss. [preprint], https://doi.org/10.5194/bg-2019-38, 2019.
Received: 29 Jan 2019 – Discussion started: 18 Feb 2019
The present publication documents the kinetic parameterisation of the related PROFILE (steady state) and ForSAFE (integrated dynamics) models. It gives the full coefficient database for about 100 minerals occurring in most soils. The text outlines the principles and methods used in setting the coefficient values. It outlines how the models with the parameterisation based on laboratory kinetics, is successful in estimating field weathering rates similar to what is being observed.
The present publication documents the kinetic parameterisation of the related PROFILE (steady...