Atmospheric Chemistry and Physics www.atmos-chem-phys.net 1680-7316 1680-7324 6 1 2006 10.5194/acp-6-187-2006 http://www.atmos-chem-phys.net/6/187/2006/ http://www.atmos-chem-phys.net/6/187/2006/acp-6-187-2006.html http://www.atmos-chem-phys.net/6/187/2006/acp-6-187-2006.pdf 187 195 2006-01-26 Technical note: Simulating chemical systems in Fortran90 and Matlab with the Kinetic PreProcessor KPP-2.1 A. Sandu R. Sander Department of Computer Science, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24060, USA Air Chemistry Department, Max-Planck Institute for Chemistry, Mainz, Germany This paper presents the new version 2.1 of the Kinetic PreProcessor (KPP). Taking a set of chemical reactions and their rate coefficients as input, KPP generates Fortran90, Fortran77, Matlab, or C code for the temporal integration of the kinetic system. Efficiency is obtained by carefully exploiting the sparsity structures of the Jacobian and of the Hessian. A comprehensive suite of stiff numerical integrators is also provided. Moreover, KPP can be used to generate the tangent linear model, as well as the continuous and discrete adjoint models of the chemical system.