frictional force"Same as friction; see also drag, drag coefficient, skin-friction coefficient.
Friction
How friction near the surface affects geostrophic and gradient wind.
Boundary Layer Wind
More on how friction affects low level winds.
Friction - the mechanical resistive force of one object on another object's relative movement when in contact with the first object
Friction Layer - same as planetary boundary layer ...
FRICTION LAYER- This is another term for the boundary layer. This is the layer of the troposphere closest to the earth's surface where friction is a significant force and wind tends to be gusty (irregular flow).
Friction layer The zone of the atmosphere between the Earth's surface and an altitude of about 1,000 m (3,280 ft), where most frictional resistance is confined.
Friction Head The decrease in total head caused by friction.
Fuel Moisture The water content of fuel particle expressed as a percent of the oven dried weight of the fuel particle.
Friction Head: The decrease in total head caused by friction.
FTP ( File Transfer Protocol): A method of data transfer that can take place between Frame Relay Networks, and Workstations.
FRICTION LAYER
The thin layer of atmosphere adjacent to the earth's surface. Surface friction is effective in slowing down wind up to approximately 1,500 to 3,000 feet above the ground.
where u* is the friction (or shear) velocity (m s-1), κ is von Karman's constant (~0.41), d is the zero plane displacement, z0 is the surface roughness (in meters), and φ is a stability term where L is the Monin-Obukhov stability parameter.
Free AtmosphereThe part of the atmosphere that lies above the frictional influence of the earth's surface.
This layer is only a portion of the planetary boundary layer, and represents the layer within which friction effects are more or less constant throughout (as opposed to decreasing with height, as they do above it).
Specifically, the term most often refers to the planetary boundary layer, which is the layer within which the effects of friction are significant.
FRICTION In meteorology, it is the turbulent resistence of the earth on the atmosphere. Considered as the resistance of fluids (air and water) to the relative motion of a solid body. The amount is dependent on the size and shape of the body.
This region is about 1 km in thickness and is characterized by a well-developed mixing generated by frictional drag as the air masses move over the Earth's surface. This layer contains approximately 10% of the mass of the atmosphere.
(gravitational or buoyant convection), motion caused only by density differences within the fluid; and forced convection, motion induced by mechanical forces such as deflection by a large-scale surface irregularity, turbulent flow caused by friction ...
Just as friction causes noise when you rub your hands together, massive friction between neighboring air molecules produces the loud noise.
If we make the simple assumption that the equivalent frictional force on the air is proportional to the wind velocity, say f = -kV per gram, then we can include this force with the pressure gradient and the Coriolis force.
The uncertainty of an instrument is caused by the unpredictable effects upon its performance of such factors as friction, backlash, and electronic noise.
French Drain: When water passes underground trough stones placed in a trench.
Friction: The force between two objects.
Geostrophic wind Theoretical wind which results from the equilibrium between horizontal components of the pressure gradient force and the Coriolis force (deviating force) above the friction layer.
Air under the influence of both the pressure gradient force and Coriolis force tends to move parallel to isobars in conditions where friction is low (1000 meters above the surface of the Earth) and isobars are straight.
BOUNDARY LAYER The lowest layer of the earth's atmosphere, usually up to 3,300 feet, or one kilometer, from the earth's surface, where the wind is influenced by the friction of the earth's surface and the objects on it.
Motion forced by mechanical forces such as deflection or friction. A cold front will cause forced convection as warmer is forced vertically above advancing cooler air.
Forward flank downdraft ...
NOAA National Weather Service - Cite This Source - This Definition
Browse Related Terms: Friction Layer, Meteogram, Planetary Boundary Layer, Variable Wind Direction
Variable Wind Direction - permalink - collapse
All > Science > Weather ...
In hydrologic terms, the decrease in total head caused by friction
Head Race
In hydrologic terms, a channel which directs water to a water wheel; a forebay.
PBL- Planetary Boundary Layer. The lowest level of the atmosphere where friction is an important force and vertical mixing is common.
PERMAFROST - a soil layer below the surface of tundra regions that remains frozen permanently.
Planetary Boundary Layer-The atmospheric boundary layer from the surface to the level where the frictional influence is absent.
Pressure-The force exerted by the interaction of the atmosphere and gravity.
Molecular viscosity The small-scale internal fluid friction that is due to the random motion of the molecules within a smooth-flowing fluid, such as air.
In the atmosphere, the Ekman spiral refers to how winds spiral to the right with height above the ground, as a result of the balance between the Coriolis, pressure gradient, and friction forces.
Sometimes this is called a FRICTION LAYER or GEOTROPH. This layer often causes winds to decrease especially at night in the lowest levels of the atmosphere, with the stronger winds only a slight distance above the layer.
A steady horizontal motion of air along straight, parallel isobars or contours in an unchanging pressure or contour field. It is assumed that there is no friction, ...
General term for a small-scale rotating column of air. They can be caused by uneven frictional effects.
The earth's atmosphere extending upward from above the planetary boundary layer (or above altitudes ranging between 1-2 kilometers above ground level), where effects of the earth's surface friction upon air motion are negligible.
frequency ...
Look at the path that summer breezes will take to reach your block - a smooth path will exert less frictional drag on the moving air, so air passing over water or flat, cleared land will move faster than if it passes over a built-up suburban area.
>> Wind: Basic requirement: The wind speed and direction in the first 30 metres or so of the atmosphere varies rapidly with height, due to the varying frictional effect of the general 'surface roughness'.
due to absorbed, incoming solar radiation and infrared radiation lost to space--as modified by such effects as the Coriolis force, the condensation of water vapor, the formation of clouds, the interaction of air masses and frontal systems, friction ...
 See also: Surface, Air, Pressure, Wind, Earth
  
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