1University of New Hampshire Institute of Earth, Oceans, and Space, Morse Hall, 8 College Road, Durham NH 03824, USA
2University of New Hampshire Department of Chemistry, Parsons Hall, 23 Academic Way, Durham NH 03824, USA
*present address: US Geological Survey, National Center, 12201 Sunrise Valley Dr., MS 432, Reston VA 20192, USA
**present address: US Military Academy, Department of Chemistry and Life Science, West Point NY 10996, USA
***present address: Department of Chemistry, Appalachian State University, Boone NC 28608, USA
****present address: Department of Earth & Atmospheric Sciences, The University of Houston, Houston TX 77204, USA
Received: 19 May 2011 – Discussion started: 20 Jul 2011
Abstract. Monoterpenes are an important class of biogenic hydrocarbons that influence ambient air quality and are a principle source of secondary organic aerosol (SOA). Emitted from vegetation, monoterpenes are a product of photosynthesis and act as a response to a variety of environmental factors. Most parameterizations of monoterpene emissions are based on clear weather models that do not take into account episodic conditions that can drastically change production and release rates into the atmosphere. Here, the monoterpene dataset from the rural Thompson Farm measurement site in Durham, New Hampshire is examined in the context of a set of known severe storm events. While some storm systems had a negligible influence on ambient monoterpene mixing ratios, the average storm event increased mixing ratios by 0.59 ± 0.21 ppbv, a factor of 93% above pre-storm levels. In some events, mixing ratios reached the 10's of ppbv range and persisted overnight. These mixing ratios correspond to increases in the monoterpene emission rate, ranging from 120 to 1240 g km−2 h−1 compared to an estimated clear weather rate of 116 to 193 g km−2 h−1. Considering the regularity of storm events over most forested areas, this could be an important factor to consider when modeling global monoterpene emissions and their resulting influence on the formation of organic aerosols.
Revised: 07 Oct 2011 – Accepted: 25 Oct 2011 – Published: 17 Nov 2011
Haase, K. B., Jordan, C., Mentis, E., Cottrell, L., Mayne, H. R., Talbot, R., and Sive, B. C.: Changes in monoterpene mixing ratios during summer storms in rural New Hampshire (USA), Atmos. Chem. Phys., 11, 11465-11476, doi:10.5194/acp-11-11465-2011, 2011.