An anemometer is commonly used asce 113 pdf free download measure wind speed. Wind speed, or wind flow velocity, is a fundamental atmospheric quantity.
Wind speed is caused by air moving from high pressure to low pressure, usually due to changes in temperature. Wind speed affects weather forecasting, aircraft and maritime operations, construction projects, growth and metabolism rate of many plant species, and countless other implications. Wind speed is now commonly measured with an anemometer but can also be classified using the older Beaufort scale which is based on people’s observation of specifically defined wind effects. These include the pressure gradient, Rossby waves and jet streams, and local weather conditions. There are also links to be found between wind speed and wind direction, notably with the pressure gradient and terrain conditions. Pressure gradient is a term to describe the difference in air pressure between two points in the atmosphere or on the surface of the Earth. Rossby waves are strong winds in the upper troposphere.
The Rossby waves are themselves a different wind speed from what we experience in the lower troposphere. Local weather conditions play a key role in influencing wind speed, as the formation of hurricanes, monsoons and cyclones as freak weather conditions can drastically affect the flow velocity of the wind. US on 12 April 1934, using a heated anemometer. Directly measuring these tornadic winds is rarely done as the violent wind would destroy the instruments.
Wind speed is a common factor in the design of structures and buildings around the world. It is often the governing factor in the required lateral strength of a structure’s design. This design wind speed is accepted by most building codes in the United States and often governs the lateral design of buildings and structures. In Canada, reference wind pressures are used in design and are based on the “mean hourly” wind speed having a probability of being exceeded per year of 1 in 50. NBC 2005 Structural Commentaries – Part 4 of Div. Ref: ASCE 7-05 commentary Figure C6-4, ASCE 7-10 C26.
Vt, and mean wind speed over one hour V3600. Wikimedia Commons has media related to Wind speed. Documentation and verification of the world extreme wind gust record: 113. The story of the world record wind”. Highest surface wind speed-Tropical Cyclone Olivia sets world record”.
Archived from the original on 2010-09-07. This page was last edited on 28 February 2018, at 20:26. This article is about the prehistoric tool. For the modern one-hand light axe, see Hatchet.