Search results
Results from the WOW.Com Content Network
A map showing the force of the mistral one day in November 2008. The wind reached a speed of 80 km/h (50 mph), with average speeds of more than 50 km/h (31 mph) near Marseille. The mistral takes place each time there is an anticyclone, or area of high pressure, in the Bay of Biscay, and an area of low pressure around the Gulf of Genoa.
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.
Mistral wind blowing near Marseille. In the center is the Chateau d'If. The winds of Provence, the region of southeast France along the Mediterranean from the Alps to the mouth of the Rhone River, are an important feature of Provençal life, and each one has a traditional local name, in the Provençal language.
A short burst of high speed wind is termed a wind gust; one technical definition of a wind gust is: the maxima that exceed the lowest wind speed measured during a ten-minute time interval by 10 knots (19 km/h; 12 mph) for periods of seconds. A squall is an increase of the wind speed above a certain threshold, which lasts for a minute or more.
A difference in air pressure causes an air displacement and generates the wind. The Coriolis force deflects the air movement to the right in the northern hemisphere and the left in the southern one, which makes the winds parallel to the isobars on an elevation in pressure card. [1] It is also referred as the geostrophic wind. [2]
Wind waves in the ocean can travel thousands of kilometers. A proper description of the physical mechanisms that cause the growth of wind waves and is in accordance with observations has yet to be completed. A necessary condition for wind waves to grow is a minimum wind speed of 0.05 m/s. [2] [16] [17] [18]
Wind setup, also known as wind effect or storm effect, refers to the rise in water level in seas, lakes, or other large bodies of water caused by winds pushing the water in a specific direction. As the wind moves across the water’s surface, it applies shear stress to the water, generating a wind-driven current.
A Wind generated current is a flow in a body of water that is generated by wind friction on its surface. Wind can generate surface currents on water bodies of any size. The depth and strength of the current depend on the wind strength and duration, and on friction and viscosity losses, [1] but are limited to about 400 m depth by the mechanism, and to lesser depths where the water is shallower. [2]