Biogeosciences www.biogeosciences.net 1726-4170 1726-4189 3 1 2006 10.5194/bg-3-103-2006 http://www.biogeosciences.net/3/103/2006/ http://www.biogeosciences.net/3/103/2006/bg-3-103-2006.html http://www.biogeosciences.net/3/103/2006/bg-3-103-2006.pdf 103 112 2006-03-14 Measurements of hydrocarbon emissions from a boreal fen using the REA technique S. Haapanala J. Rinne K.-H. Pystynen H. Hellén H. Hakola T. Riutta University of Helsinki, Department of Physical Sciences, Helsinki, Finland Finnish Meteorological Institute, Air Chemistry Laboratory, Helsinki, Finland University of Helsinki, Department of Forest Ecology, Helsinki, Finland Fluxes of biogenic volatile organic compounds (VOC) and methane were measured above a boreal fen. Vegetation on the fen is dominated by <I>Sphagnum</I> mosses and sedges. A relaxed eddy accumulation (REA) system with dynamic deadband was designed and constructed for the measurements. Methane, C₂-C₆ hydrocarbons and some halogenated hydrocarbons were analysed from the samples by gas chromatographs equipped with FID and ECD. A significant flux of isoprene and methane was detected during the growing seasons. Isoprene emission was found to follow the common isoprene emission algorithm. Average standard emission potential of isoprene was 680 &micro;g m^-2 h^-1. Fluxes of other non-methane hydrocarbons were below detection limit.