The current state and future direction of Eulerian models in simulating the tropospheric chemistry and transport of trace species: a review

Limitations on comprehensive tropospheric chemistry/transport models are discussed within the context of a set of issues currently facing the environmental scientific and policy-making communities. A number of central improvements are discussed in a prioritized manner, with consideration of the key progress necessary to include feedback processes between meteorology and chemistry, aerosol formation, in cloud development with subsequent effects on wet removal, dry deposition and surface exchange processes, and impacts of chemical perturbations on radiation, climate, and weather. These improvements would result in a “third-generation model”. The computational framework for this code is outlined, and estimates of required computer resources presented.