Pertti. Hari, Pasi Aalto, Kaarle Hämeri, Markku. Kulmala, Tapani. Lahti, Sari. Luoma, Lauri Palva, Toivo Pohja, Erkki. Pulliainen, Erkki. Siivola, Timo Vesala. (1994). Air pollution in eastern Lapland : challenge for an environmental measurement station. Silva Fennica vol. 28 no. 1 article id 5526. https://doi.org/10.14214/sf.a9160

Keywords: photosynthesis; automation; carbon dioxide; ozone; measurement systems; aerosols; sulphur dioxid; weather

Abstract | View details | Full text in PDF | Author Info

The Värriö environmental measurement station has been designed and constructed during 1991 and 1992. The measurement system consists of measurement units for gases (sulphur dioxide, ozone, carbon dioxide), particles, photosynthesis and irradiation. A meteorological station is also included. The preliminary measurement period was started on August, 1991. During the first year (1991–1992) some parts of the system were redeveloped and rebuilt. Full, continuous measurement started in August 1992. The system has been working quite reliably, with good accuracy. The preliminary results show that pollution episodes are observed when the wind direction is from Monchegorsk or Nikel, the main emission sources in Kola Peninsula.

Hari, E-mail: ph@mm.unknown
Aalto, E-mail: pa@mm.unknown
Hämeri, E-mail: kh@mm.unknown
Kulmala, E-mail: mk@mm.unknown
Lahti, E-mail: tl@mm.unknown
Luoma, E-mail: sl@mm.unknown
Palva, E-mail: lp@mm.unknown
Pohja, E-mail: tp@mm.unknown
Pulliainen, E-mail: ep@mm.unknown
Siivola, E-mail: es@mm.unknown
Vesala, E-mail: tv@mm.unknown

Category : Research article

article id 529, category Research article

Tuula Aalto, Pertti Hari, Timo Vesala. (2002). Comparison of an optimal stomatal regulation model and a biochemical model in explaining CO2 exchange in field conditions. Silva Fennica vol. 36 no. 3 article id 529. https://doi.org/10.14214/sf.529

Keywords: photosynthesis; Scots pine; optimization; Pinus sylvestris L.; CO2 exchange; biochemical model

Abstract | View details | Full text in PDF | Author Info

Gas exchange of Pinus sylvestris L. was studied in subarctic field conditions. Aspects on optimal control of the gas exchange were examined using approach by Hari et al. (Tree Phys. 2: 169–175, 1986). Biochemical model by Farquhar et al. (Planta 149: 78–90, 1980) was utilized to describe the photosynthetic production rate of needles. The model parameters were determined from field measurements. The results from the optimization approach and biochemical model were compared and their performance was found quite similar in terms of R2 calculated using measured exchange rates (0.89 for optimization model and 0.85 for biochemical model). Minor differences were found in relation to responses to intercellular carbon dioxide concentration and temperature.

Aalto, Finnish Meteorological Institute, Air Quality Research, Sahaajankatu 20 E, FIN-00810 Helsinki, Finland E-mail: tuula.aalto@fmi.fi
Hari, University of Helsinki, Dept. of Forest Ecology, P.O. Box 27, FIN-00014 University of Helsinki, Finland E-mail: ph@nn.fi
Vesala, University of Helsinki, Dept. of Physics, P.O. Box 64, FIN-00014 University of Helsinki, Finland E-mail: tv@nn.fi

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