ACPD Atmospheric Chemistry and Physics Discussions ACPD 1680-7375 Copernicus GmbH Göttingen, Germany 10.5194/acpd-6-2923-2006 Application of thermal dissociation-laser induced fluorescence (TD-LIF) to measurement of HNO<sub>3</sub>, &Sigma;alkyl nitrates, &Sigma;peroxy nitrates, and NO<sub>2</sub> fluxes using eddy covariance Farmer D. K. 1 Wooldridge P. J. 1 Cohen R. C. 1 2 Department of Chemistry; University of California, Berkeley, CA, 94720, USA Dept. of Earth and Planetary Science; University of California, Berkeley, CA, 94720, USA 12 04 2006 6 2 2923 2964 This is an open-access article ditributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. This article is available from http://www.atmos-chem-phys-discuss.net/6/2923/2006/acpd-6-2923-2006.html The full text article is available as a PDF file from http://www.atmos-chem-phys-discuss.net/6/2923/2006/acpd-6-2923-2006.pdf

Nitrogen exchange between the atmosphere and biosphere directly influences atmospheric composition. While much is known about mechanisms of NO and N<sub>2</sub>O emissions, instrumentation for the study of mechanisms contributing to exchange of other major nitrogen species is quite limited. Here we describe the application of a new technique, thermal dissociation-laser induced fluorescence (TD-LIF), to eddy covariance measurements of the fluxes of NO<sub>2</sub>, total peroxy acyl and peroxy nitrates, total alkyl and multifunctional alkyl nitrates, and nitric acid. The technique offers the potential for investigating mechanisms of exchange of these species at the canopy scale over timescales from days to years. Examples of flux measurements at a ponderosa pine plantation in the mid-elevation Sierra Nevada Mountains in California are reported and used to evaluate instrument performance.