Eddy Covariance Fluxes of Peroxyacetyl Nitrate (PAN) to a Coniferous Forest
Abstract
As part of the CELTIC study, we have used a fast response chemical ionization mass spectrometer (CIMS) system to make rapid measurements (4 Hz) of peroxyacetyl nitrate (PAN). Concurrent fast wind velocities were then used to obtain direct eddy covariance fluxes of PAN. Fluxes were measured for eight consecutive days in July, 2003 at a loblolly pine forest in North Carolina. Covariances between PAN concentration and vertical wind velocity indicated consistent deposition fluxes that ranged up to approximately -12 ngN m-2 s-1. The average daytime flux was ∼ -2.5 ngN m-2 s-1 and the diurnal profile was consistent with uptake through plant stomates. Deposition velocities also showed a daytime maximum with an average daytime value of 7.1 mm s-1. There was also some indication of nocturnal uptake when canopy elements were wet. These preliminary measurements suggest that uptake of PAN to forest canopies is significant and may play a role in both atmospheric chemical processes and nitrogen cycling within ecosystems.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2003
- Bibcode:
- 2003AGUFM.A32A0114T
- Keywords:
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- 0315 Biosphere/atmosphere interactions;
- 0322 Constituent sources and sinks