Tropospheric carbon monoxide and hydrogen measurements over Kalimantan in Indonesia and northern Australia during October, 1997

During the PACE-5 campaign over Australia and Indonesia in October 1997, we used an aircraft to measure carbon monoxide (CO) and hydrogen (H-2). Latit udinal distributions of CO and H-2 clearly showed a large increase from nor thern Australia to Kalimantan in Indonesia. Elevated CO levels over norther n Australia were observed only in the smoke plumes of savanna furs. A thick smoke haze from forest fires over Kalimantan contained very high CO mixing ratios of 3 to 9 ppm. These enhanced CO mixing ratios correlated well with increased concentrations of H-2, nitrogen oxides (NOx), and aerosols. Emis sion ratios from biomass burning in Kalimantan ranged 0.06 0.1 fbr H-2/CO ( ppb/ppb), 0.0002 to 0.0005 for NOx/CO (ppb/ppb), and 0.43 to 1.0 for number of aerosols/CO (cm(-3)/ppb). These values were much lower than emission ra tios in northern Australia. This difference suggests that the biomass burni ng in Indonesia was intense and that, due to a strong El Nino event, an uni que composition of trace gases was formed in the smoke haze.