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Wind speed on the Beaufort scale is based on the empirical relationship: [6] v = 0.836 B 3/2 m/s; v = 1.625 B 3/2 knots (=) where v is the equivalent wind speed at 10 metres above the sea surface and B is Beaufort scale number.
An anemometer is commonly used to measure wind speed. Global distribution of wind speed at 10m above ground averaged over the years 1981–2010 from the CHELSA-BIOCLIM+ data set [1] In meteorology, wind speed, or wind flow speed, is a fundamental atmospheric quantity caused by air moving from high to low pressure, usually due to changes in ...
Historically, the Beaufort wind force scale, created by Francis Beaufort, provides an empirical description of wind speed based on observed sea conditions. Originally it was a 13-level scale (0–12), but during the 1940s, the scale was expanded to 18 levels (0–17). [ 21 ]
Isotach maps, analyzing lines of equal wind speed, [3] on a constant pressure surface of 300 or 250 hPa show where the jet stream is located. Use of constant pressure charts at the 700 and 500 hPa level can indicate tropical cyclone motion.
As with the Fujita scale, the Enhanced Fujita scale is a damage scale and only an estimate for actual wind speeds. While the wind speeds associated with the damage listed did and have not undergone empirical analysis (such as detailed physical or any numerical modeling) due to expensive costs, the wind speeds were obtained through a process ...
The station model uses a wind barb to show both wind direction and speed. The wind barb shows the speed using "flags" on the end. Each half of a flag depicts 5 kn (9.3 km/h; 5.8 mph) Each full flag depicts 10 kn (19 km/h; 12 mph) Each pennant (filled triangle) depicts 50 kn (93 km/h; 58 mph) [4]
In common usage, wind gradient, more specifically wind speed gradient [1] or wind velocity gradient, [2] or alternatively shear wind, [3] is the vertical component of the gradient of the mean horizontal wind speed in the lower atmosphere. [4] It is the rate of increase of wind strength with unit increase in height above ground level.
Consequently, a wind blowing from the north has a wind direction referred to as 0° (360°); a wind blowing from the east has a wind direction referred to as 90°, etc. Weather forecasts typically give the direction of the wind along with its speed, for example a "northerly wind at 15 km/h" is a wind blowing from the north at a speed of 15 km/h ...