Wind gust World Meteorological Organization. Any significant variation at this mean wind during the ten minutes preceding the observation are noted as gusts in messages such as METAR. It is generally reported in METAR when the peak wind speed reaches at least 16 knots and the variation in wind speed between the peaks and average wind is at least 9 to 10 knots. In marine meteorology, the top speed of a burst is expressed in meters per second (m/s) or in knots, while the Beaufort scale is used for reporting the mean speed. When the maximum speed exceeds the average speed by
Environmental impact of wind power made no mention of avian deaths per unit of electricity produced, which excluded meaningful comparisons between different energy sources. More importantly, it concluded, the most visible impacts of a technology, as measured by media exposure, are not necessarily the most flagrant ones. Sovacool estimated that in the United States wind turbines kill between 20,000 and 573,000 birds per year, and although he regards either figure as minimal compared to bird deaths from other causes. He uses the lower 20,000 figure in his study and table (see "Causes of avian mortality" table) to arrive at a direct mortality rate per unit