Publication Date:
2011-06-25
Description:
Isoprene suppression of new particle formation in a mixed deciduous forest Atmospheric Chemistry and Physics, 11, 6013-6027, 2011 Author(s): V. P. Kanawade, B. T. Jobson, A. B. Guenther, M. E. Erupe, S. N. Pressley, S. N. Tripathi, and S.-H. Lee Production of new particles over forests is an important source of cloud condensation nuclei that can affect climate. While such particle formation events have been widely observed, their formation mechanisms over forests are poorly understood. Our observations made in a mixed deciduous forest with large isoprene emissions during the summer displayed a surprisingly rare occurrence of new particle formation (NPF). Typically, NPF events occur around noon but no NPF events were observed during the 5 weeks of measurements. The exceptions were two evening ultrafine particle events. During the day, sulfuric acid concentrations were in the 10 6 cm −3 range with very low preexisting aerosol particles, a favorable condition for NPF to occur even during the summer. The ratio of emitted isoprene carbon to monoterpene carbon at this site was similar to that in Amazon rainforests (ratio 〉10), where NPF events are also very rare, compared with a ratio
Print ISSN:
1680-7316
Electronic ISSN:
1680-7324
Topics:
Geosciences
