Contribution of oil palm isoprene emissions to tropospheric ozone levels in the Distrito Metropolitano de Quito (Ecuador)

Volatile organic compound (VOC) emissions from vegetation are important in the Distrito Metropolitano de Quito (DMQ). In particular, oil palm (Elaeis guineensis) isoprene emissions are significant near the DMQ. Oil palm cultivation is promoted because of the growing demand for biodiesel production. The contribution of isoprene from oil palm to tropospheric ozone (O₃) production was estimated by numerical simulation for the period 2-28 of September 2006, using estimates of emissions from the DMQ in the Eulerian chemical transport model WRF-Chem. On-road traffic, power facilities and other industries, vegetation, services stations and solvent use were considered as emission sources, under the following scenarios: 1) without oil palm, 2) with oil palm plantation in 2003; and, 3) with an expected future plantation. Two groups of emission rates were used: 1) a group of mid-range emission factors (up to 51 g g^-1 h^-1) and 2) a high isoprene emission factor (172.9 g g^-1 h^-1). Results indicate that increasing areas of oil palm plantations in the future could increase O3 concentrations. Scenario 3) with the high emission factor, provides maximum hourly anomalies of 17.9 g m^-3 over the urban zone. Scenario 3), with the mid-range emission factors, results in maximum hourly anomalies of 2.7 g m^-3.