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 673, category Research article

Lauri Palva, Eero Garam, Sari Palmroth, Raimo Sepponen, Pertti Hari. (1998). Utilizing a multipoint measuring system of photosynthetically active radiation in photosynthetic studies within canopies. Silva Fennica vol. 32 no. 4 article id 673. https://doi.org/10.14214/sf.673

Keywords: carbon dioxide; instrumentation; measurement; photosynthetically active radiation

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

A novel multipoint measuring system of photosynthetically active radiation (PAR) has been constructed and operated within a Scots pine canopy. A regular grid of 800 measuring points has been incorporated into a cuvette to observe the spatial and temporal distribution of PAR incident on the needles of a twig along with simultaneous measurements of the CO2 exchange in order to determine the dependence of photosynthesis on PAR. It was shown that large errors can result if the photosynthetic rate is estimated using the mean value of PAR instead of the instantaneous values of PAR detected at given points in the region of the needles. The results demonstrate that the obtained regression between the CO2 exchange rate estimated using the multipoint PAR measuring system and the measured CO2 exchange rate is as good within a canopy as in unshaded conditions.

Palva, Helsinki University of Technology, Applied Electronics Laboratory, P.O. Box 3000, FIN-02015 HUT, Finland E-mail: lauri.palva@hut.fi
Garam, Helsinki University of Technology, Applied Electronics Laboratory, P.O. Box 3000, FIN-02015 HUT, Finland E-mail: eg@nn.fi
Palmroth, University of Helsinki, Dept. of Forest Ecology, P.O. Box 24, FIN-00014 University of Helsinki, Finland E-mail: sp@nn.fi
Sepponen, Helsinki University of Technology, Applied Electronics Laboratory, P.O. Box 3000, FIN-02015 HUT, Finland E-mail: rs@nn.fi
Hari, University of Helsinki, Dept. of Forest Ecology, P.O. Box 24, FIN-00014 University of Helsinki, Finland E-mail: ph@nn.fi

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