Measurements at SMEAR II

SMEAR II is a rural background site with low local particle matter emissions. It is also one of the first most developed stations measuring the ecosystem-atmosphere interactions. Special attention in SMEAR II is paid to long-term observations on atmospheric composition, energy and matter fluxes between ecosystems and atmosphere, and ecophysiological phenomena. Exceptional selection of different types of measurement setups are continuously observing hundreds of variables within mineral soil or peat layer, below and inside forest canopy, above the canopy and lake surface, below the lake surface. The measurements are located around the measurement huts where soil pits, mast and towers allow installing measurements to the different parts of ecosystem and atmosphere. In addition to those, measurements are located to smaller measurement stations on nearby lake Kuivajärvi and Siikaneva fen/mire. Large proportion of the measurements are part of ACTRIS, Integrated Carbon Observation System ICOS (https://www.icos-ri.eu/) and Long-Term Ecosystem Research in Europe LTER-Europe (http://www.lter-europe.net/lter-europe).

Numerous aerosol measurement campaigns with topical scientific breakthroughs have been done at SMEARII from 1996 and they continue. Those campaigns have strong base because of the well-qualified continuous aerosol precursor concentrations, physical, optical and chemical properties measurements at SMEARII.The aerosol instruments are located in Hitu-hut, small-hut, main-hut, tower (35 m), mast (127 m), hall roof, cloud-radar field and container-area. All aerosol measurements are qualified by the continuous audits, calibrations at site and comparison campaigns by European Center for Aerosol Calibration (ECAC).These continuous aerosol measurements at SMEARII are part of the European Aerosols, Clouds, and Trace gases Research Infra Structure ACTRIS, http://www.actris.eu/).

The possibility to combine measurement material multidisciplinary sheds like to complex scientific questions such as feedback loops between ecosystems, atmosphere and climate. List of the measurements can be found here: List of the measurements

Photos by J.Aalto, M.Loponen and H.Keskinen