High acetone concentrations throughout the 0-12 km altitude range over the tropical rainforest in Surinam

摘要: Airborne measurements of acetone were performed overthe tropical rainforest in Surinam(2°–7° N, 54°–58° W, 0–12 kmaltitude) during the LBA-CLAIRE campaign March1998, using a novel proton transfer reaction massspectrometer (PTR-MS) that enables on-linemonitoring volatile organic compounds (VOC) with ahigher affinity than water. The measuredacetone volume mixing ratios ranged from ∼0.1 nmol/molup to ∼8 nmol/mol an overall average 2.6nmol/mol and standard deviation 1.0 nmol/mol. Theobserved altitude profile correlations CO,acetonitrile, propane wind direction are discussedwith respect potential sources. No linearcorrelation between CO wasobserved, at variance results previousmeasurement campaigns. mean acetone/CO ratio(0.022) was substantially higher typical valuesfound before. abundance appears beinfluenced, but not dominated, by biomass burning,thus suggesting large emissions and/oracetone precursors, such as possibly 2-propanol, fromliving plants or decaying litter rainforest.