Počet záznamů: 1
Wind-stilling in the light of wind speed measurements: the Czech experience
- 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: 1.578, rok: 2016
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