Počet záznamů: 1  

Wind-stilling in the light of wind speed measurements: the Czech experience

  1. 1. 0483909 - UEK-B 2019 RIV DE eng J - Článek v odborném periodiku
    Brázdil, Rudolf - Valík, A. - Zahradníček, Pavel - Řezníčková, Ladislava - Tolasz, R. - Možný, M.
    Wind-stilling in the light of wind speed measurements: the Czech experience.
    Climate Research. Roč. 74 (2018), s. 131-143 ISSN 0936-577X
    Grant CEP: GA MŠk(CZ) LO1415; GA ČR(CZ) GA15-11805S
    Institucionální podpora: RVO:86652079
    Klíčová slova: universal anemograph * vaisala wind-speed sensors * wind speed * homogenisation * wind stilling * Czech Republic
    Kód oboru RIV: DG - Vědy o atmosféře, meteorologie
    Obor OECD: Meteorology and atmospheric sciences
    Impakt faktor: 1.859, rok: 2017

    Changes of instruments often give rise to significant break-points in wind-speed
    series. This is particularly applicable when measurements are automated, a process that started in
    the Czech Republic in the mid-1990s, when standard universal anemographs were progressively
    replaced by the Vaisala WAA251 sensor (cup anemometer) and the WS425 sensor (ultrasonic).
    Parallel wind speed measurements, by universal anemographs and Vaisala sensors, at the Doksany
    (2000−2016) and Kocelovice (2000−2016) stations enabled differences in the 2 types of measurement
    to be analysed. Vaisala sensors measure, on average, higher wind-speeds than universal
    anemographs, particularly in calm situations and at low wind speeds. The differences between the
    2 types of instrument do not depend on wind direction. Linear trends of homogenised daily mean
    wind-speed series from only a universal anemograph or combined from universal anemograph
    and Vaisala sensors generally exhibit no important differences in their significance or values. This
    could indicate that observed decreasing trends in mean daily wind-speeds (‘stilling’) cannot be
    attributed to changes of wind-speed measurements to automated devices; with respect to only
    2 stations being investigated, this is biased by high uncertainty. In contrast, important differences
    in the 2 types of measurement, both in linear trends and their significance, appear for series of
    3 daily readings (07:00, 14:00 and 21:00 h LMT).
    Trvalý link: http://hdl.handle.net/11104/0279089