Forward, tangent linear, and adjoint Runge-Kutta methods for stiff chemical kinetic simulations.

This paper investigates numerical methods for direct decoupled sensitivity and discrete adjoint sensitivity analysis of stiff systems based on implicit Runge-Kutta schemes. Efficient implementations of tangent linear and adjoint schemes are discussed for two families of methods: fully implicit three-stage Runge-Kutta and singly diagonally-implicit Runge-Kutta. High computational efficiency is attained by exploiting the sparsity patterns of the Jacobian and Hessian. Numerical experiments with a large chemical system used in atmospheric chemistry illustrate the power of the stiff Runge-Kutta integrators and their tangent linear and discrete adjoint models. Through the integration with the Kinetic PreProcessor KPP-2.2 these numerical techniques become readily available to a wide community interested in the simulation of chemical kinetic systems. [ABSTRACT FROM AUTHOR]