Flexible Code Metastructures for Photochemical Modeling

We propose to create an integrated code environment for atmospheric photochemical modeling codes that will allow both scientists and data analysts to tailor photochemical reaction schemes within a windows-oriented user environment, to compile and execute the codes, and to inspect the results without actual editing of source codes. The innovative aspect of this proposed development is the design and implementation of an "automated updating" capability that, based on simple screen input from a user, will update the listings of reactants and reaction paths in the model photochemistry, regenerate the "map" associating reactants with reaction paths, and execute "intermediate chemistry expression generators" that in effect rewrite relevant sections of the photochemical code automatically. These "generators" are characteristic of the numerical technique used by the code in computing reactant abundances; in this proposal, we restrict our attention to the Newton-Raphson iterative convergence technique for obtaining steady-state abundances. Development of this environment with "automated updating" directly serves the subtopic need for the continual extension of current photochemical model capabilities while, on the one hand, adhering to operational standards and, on the other hand, making the code accessible to data analysts in support of NASA missions.