The Response of the Dines Anemometer to Gusts and Comparisons with Cup Anemometers

Abstract

The Dines pressure tube anemometer was the primary wind speed recording instrument used in Australia until it was replaced by Synchrotac cup anemometers in the 1990s. Simultaneous observations of the gust wind speeds recorded using both types of anemometers during tropical cyclones have, however, raised questions about the equivalency of the gust wind speeds recorded using the two instruments. An experimental study of the response of both versions of the Dines anemometer used in Australia shows that the response of the anemometer is dominated by the motion of the float manometer used to record the wind speed. The amplitude response function shows the presence of two resonant peaks, with the amplitude and frequency of the peaks depending on the instrument version and the mean wind speed. Comparison of the gust wind speeds recorded using Dines and Synchrotac anemometers using random process and linear system theory shows that, on average, the low-speed Dines anemometer records values 2%-5% higher than those recorded using a Synchrotac anemometer under the same conditions, while the high-speed Dines anemometer records values 3%-7% higher, depending on the mean wind speed and turbulence intensity. These differences are exacerbated with the adoption of the WMO-recommended 3-s moving average gust wind speed when reporting the Synchrotac anemometer gust wind speeds, rising to 6%-12% and 11%-19% for low-and high-speed Dines anemometers, respectively. These results are consistent with both field observations and an independent extreme value analysis of simultaneously observed gust wind speeds at seven sites in northern Australia.

Improved extreme wind speed estimation for wind engineering applications

“…In Australia and other locations (Miller et al, 2011), the ''peak'' wind gust recorded by the Dines anemometer, which may have been responsible for the somewhat arbitrary 3 s value used in codes and standards, is significantly higher ( E15%) than a 3 s moving average gust recorded by cup anemometry.…”

The UK’s highest low‐level wind speed re‐examined: the Fraserburgh gust of 13 February 1989

“…Such a committee, which could reside under the mantle of the RMetS's Meteorological Observing Systems Special Interest Group, would have terms of reference similar to that of the WMO Global Archive of Weather and Climate Extremes (Purevjav et al ., 2015) and of the National Climate Extremes Committee in the USA (Cerveny et al ., 2007). Impartial assessment of UK extreme weather records is particularly relevant for record gusts because these records are long‐standing and there remain unresolved questions concerning the homogeneity of wind speed records made by older anemometer instruments (Smith, 1981; Miller et al ., 2013; Cook, 2014). The creation of an impartial weather and climate extremes panel in the UK would ensure the validity and reliability of extremes by collecting and assessing all the available evidence before such extremes are published in ‘official’ listings, and act to ensure permanent and secure archiving of all documentation related to the event.…”

Effects of sensor response and moving average filter duration on maximum wind gust measurements

“…Using observed wind data in meteorological and climatological studies without correction can introduce significant errors and contaminate the results (Azorin-Molina et al, 2014;Safaei Pirooz et al, 2018a;Powell et al, 1996;Masters et al, 2010). This is particularly true for gust wind speeds, which are extremely sensitive to the anemometer response characteristics and to the duration of measurement (Miller et al, 2013;Safaei Pirooz and Flay, 2018;Holmes et al, 2014;Holmes and Ginger, 2012;Azorin-Molina et al, 2019).…”

“…Accurate knowledge on the climatology of wind gusts and gust information, including gust duration, is of great importance to various industries, such as the building industry, which needs accurate assessment of maximum load or fatigue on structures, and the wind energy industry for wind farm feasibility studies (Beljaars, 1987). The effects of gust duration on maximum gust wind speeds have been recognised by several researchers (Masters et al, 2010;Miller et al, 2013;Safaei Pirooz and Flay, 2018;Holmes et al, 2014;Holmes and Ginger, 2012;Beljaars, 1987). An obvious way of characterising wind gusts is to define a gust duration related to the width of the spike in a wind speed time series causing the extreme wind in a T-second interval (e.g.…”