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HYSPLIT and the SO2 to SO4 Conversion Module

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In 1990, a simple Lagrangian-based sulfur chemistry module was developed (Rolph, 1992 and 1993) to be incorporated into the HYSPLIT 3.0 model. The sulfur module is nonlinear (in hydrogen peroxide) and includes gas- and aqueous-phase oxidation of sulfur dioxide (SO2) and dry and wet removal of SO2 and sulfate (SO-) particles. The current version is identical to the original, except that it has been incorporated into HYSPLIT 4.6.

Rolph G.D., Draxler R.R. and de Pena R.G. (1993) The use of model-derived and observed precipitation in long-term sulfur concentration and deposition modeling . Atmospheric Environment 27A, No 13, 2017-2037.

Rolph G.D., Draxler R.R. and de Pena R.G. (1992) Modeling sulfur concentrations and depositions in the United States during ANATEX. Atmospheric Environment 26, 73-93.

Equation Overview

  1. Decrease of SO2 along the trajectory

    -d(SO2)/dt = (Kd + Kw + Kdd + Kwd) [SO2]

  2. Rate Change of SO2

    d(SO2)/dt = (Kd + Kw) [SO2] - (Kd' + Kw') [SO2-4]

  3. Aqueous-phase oxidation by H2O2

    -d(SO2)/dt = Kw [SO2]