Abstract
Isoprene and alpha -pinene emission rates are estimated for the region around London, UK. Isoprene is the dominant biogenic nonmethane hydrocarbon species by mass in the study area. Chemical degradation schemes for these hydrocarbons are coupled to an existing urban plume model previously applied to London, and the influence of each hydrocarbon on ozone formation was assessed by comparing model runs to a base case scenario. The effect is shown to be small, as O sub(3) levels in the plume are increased by the addition of the new schemes by as much as 8 ppb. A model run with biogenic hydrocarbons and nitrogen oxide emissions demonstrates the VOC-limited behavior of the urban plume.