Airborne measurements of aerosols and carbon dioxide during a prescribed fire experiment at a boreal forest site

Peer reviewe

Water balance of a boreal Scots pine forest

In terrestrial ecosystems, the amount and availability of water is one of the key factors affecting the net primary productivity and other biological processes of the system. At the SMEAR-II station, we have monitored the water balance of two adjacent micro-catchments since 1997. In this study, we report the long-term measurements of precipitation, throughfall, snow depth, soil water content, runoff and evapotranspiration and the annual water balances based on these measurements and discuss the uncertainties related to different measurements. The proportion of throughfall, evapotranspiration and runoff was 67%, 43% and 32% of the annual precipitation, respectively. The measured amounts of evapotranspiration and runoff were so small that the aim of closing the water balance of the studied system was not fully reached. The largest uncertainties are related to the evapotranspiration measurements and the determination of the actual surface area of the catchments used in the calculation of the runoff

Airborne measurements over the boreal forest of southern Finland during new particle formation events in 2009 and 2010

Peer reviewe

Accurate measurements of CO2 mole fraction in the atmospheric surface layer by an affordable instrumentation

We aimed to assess the feasibility of an affordable instrumentation, based on a non-dispersive infrared analyser, to obtain atmospheric CO2 mole fraction data for background CO2 measurements from a flux tower site in southern Finland. The measurement period was November 2006 to December 2011. We describe the instrumentation, calibration, measurements and data processing and a comparison between two analysers, inter-comparisons with a flask sampling system and with reference gas cylinders and a comparison with an independent inversion model. The obtained accuracy was better than 0.5 ppm. The inter-comparisons showed discrepancies ranging from -0.3 ppm to 0.06 ppm between the measured and reference data. The comparison between the analyzers showed a 0.1 +/- 0.4 ppm difference. The trend and phase of the measured and simulated data agreed generally well and the bias of the simulation was 0.2 +/- 3.3 ppm. The study highlighted the importance of quantifying all sources of measurement uncertainty

Biomass-burning smoke episodes in Finland from eastern European wildfires

Peer reviewe