Atmospheric Budget Of Acetone
. The atmospheric budget and distribution of acetone are investigated by using best a priori estimates of sources and sinks to constrain a global 3-dimensional atmospheric model simulation, and then using atmospheric observations from 14 surface sites and 5 aircraft missions to improve these estimat...
| Main Authors: | , , , , , , , |
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| Other Authors: | |
| Format: | Text |
| Language: | English |
| Published: |
2001
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| Subjects: | |
| Online Access: | http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.28.8675 http://www-as.harvard.edu/chemistry/trop/publications/jacob2001/paper.new.pdf |
| Summary: | . The atmospheric budget and distribution of acetone are investigated by using best a priori estimates of sources and sinks to constrain a global 3-dimensional atmospheric model simulation, and then using atmospheric observations from 14 surface sites and 5 aircraft missions to improve these estimates through an inversion analysis. Matching the observed acetone concentrations over the South Pacific requires a large photochemical ocean source, while matching the the low concentrations observed at European sites in winter-spring and in the Arctic in summer implies a large microbial ocean sink (seawater saturation ratio in the range 0.7-0.85). The seasonal decrease in concentrations observed in Europe from summer to fall argues against a large acetone source from plant decay. Continental observations in the tropics and at northern midlatitudes in summer indicate a large acetone source from terrestrial vegetation, while observations in the northern hemisphere outside summer imply a large source from atmospheric oxidation of isoalkanes (propane, isobutane, isopentane). Simulation of isoalkanes in the global model and comparison to observations yields best global emission estimates of 12 Tg C yr -1 for propane (including only 0.6 Tg C yr -1 from biomass burning), 3.6 Tg C yr -1 for isobutane, and 5.0 Tg C yr -1 for isopentane. Our best estimate of the acetone budget in the global 3-D model simulates the ensemble of atmospheric observations with a goodness-of-fit statistic c 2 of 0.39. It uses a global acetone source of 95 15 Tg yr -1 including 33 9Tgyr -1 from terrestrial vegetation, 27 6Tgyr -1 from the oceans, 21 5Tgyr -1 from oxidation of isoalkanes, 6 3Tgyr -1 from oxidation of monoterpenes, 5 2Tgyr -1 from biomass burning, 2 5Tgyr -1 from pl. |
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