First eddy covariance flux measurements by PTR-TOF
- 1Institut für Ionenphysik und Angewandte Physik, Universität Innsbruck, Innsbruck, Austria
- 2Ionicon Analytik, Innsbruck, Austria
- 3Institut für Ökologie, Universität Innsbruck, Innsbruck, Austria
- 4Atmospheric Chemistry Division, National Center for Atmospheric Research, Boulder, CO 80307, USA
Abstract. The recently developed PTR-TOF instrument was evaluated to measure methanol fluxes emitted from grass land using the eddy covariance method. The high time resolution of the PTR-TOF allowed storing full mass spectra up to m/z 315 with a frequency of 10 Hz. Three isobaric ions were found at a nominal mass of m/z 33 due to the high mass resolving power of the PTR-TOF. Only one of the three peaks contributed to eddy covariance fluxes. The exact mass of this peak agrees well with the exact mass of protonated methanol (m/z 33.0335). The eddy covariance methanol fluxes measured with PTR-TOF were compared to virtual disjunct eddy covariance methanol fluxes simultaneously measured with a conventional PTR-MS. The methanol fluxes from both instruments show excellent agreement.