THE SMART-FOREST MODEL
calculates the deposition, emission, and chemical reactions of 34 atmospheric trace gases (e.g. Ozone, NO2, HNO3, PAN, ISOPRENE, TERPENE, SO2, etc.) within the boundary layer up to 125 meters.
It is a 1-d reaction-transport model, tuned for the solling spruce site, Germany.
The model time step is one second. 1 day calculation takes about 5 minutes on a workstation (1999).
The model consists of about three parts:
1) chemical reactions, which where taken from RADM-2 and in new version from the RACM mechanism from Stockwell et al.(1998). It deals now with about 34 chemical tracers within tropospheric photochemistry. It could be easily enhanced or melted down further.
2) transport mechanism: simple 12-layer approach from 125 meters above, down to soil. you need the turbulent transport parameters (turbulent exchange coefficient derived by micrometeorological gradient measurments: wind speed, humidity, temperature, radiation balance or eddy correlation measurements)
3) deposition/emission model onto leafes (stomata, cuticle) , soil (O3, so2, pan, no2, etc.) and from leafes (terpene, isoprene) or soil (no-emission).
The model world consists of the first 125 meters of atmosphere, the trees and the soil and the sun. Each of this 34 compartments represented by their physical and chemical and biological functions.
The model is designed to derive deposition parameters and investigate the deposition processes of reactive trace gases and their chemical reactions. we measured vertical profiles of tracers (o3,no2,no,pan,so2,noy) and the micrometeorological transport parameters of the lower troposphere on a 52m tower at the solling spruce stand. Then we took only the 52m concentration of all compounds and the vertical turbulent exchange parameters of boundary layer.
inside the model we tuned the surface deposition parameters in this way, that the vertical concentration gradient of model and of measurement match each other. now it was possible to calculate the amount of e.g. ozone, which is penetrating stomata, which is deposited onto cuticula and the fraction of e.g. ozone, which is destroyed via chemical conversion during the deposition process.
A model description is available at:
K.-G. Schnitzler, 1999: 'Der Transfer von gasfoermigen Spurenstoffen in einen Fichtenwald - Entwicklung und Anwendung eines eindimensionalen reaktionskinetischen Transportmodells' Berichte des Forschungszentrums Waldoekosysteme, Reihe A, Bd. 166, ISSN 0939-1347
you can ask for this book at http://www.gwdg.de/~fzw/homee/hometest.htm