What is meant by geostrophic flow?
In atmospheric science, geostrophic flow (/ˌdʒiːəˈstrɒfɪk, ˌdʒiːoʊ-, -ˈstroʊ-/) is the theoretical wind that would result from an exact balance between the Coriolis force and the pressure gradient force. This condition is called geostrophic equilibrium or geostrophic balance (also known as geostrophy).
How do you calculate geostrophic wind velocity?
Using the coriolis parameter, the equations for the coriolis acceleration in terms of the component vectors (u and v) are:
- Fx = f⋅v.
- Fy = −f⋅u.
- Gx = −g⋅(∂Φ/∂x)
- Gy = −g⋅(∂Φ/∂y)
- Gx = −g⋅(ΔΦ/Δx)
- Gy = −g⋅(ΔΦ/Δy)
- ug⋅f = −g⋅(∂Φ/∂y)
- vg⋅f = g⋅(∂Φ/∂x)
What are Geotropic winds?
: a wind whose direction and speed are determined by a balance of the pressure-gradient force and the force due to the earth’s rotation.
What causes geostrophic flow?
geostrophic motion, fluid flow in a direction parallel to lines of equal pressure (isobars) in a rotating system, such as the Earth. Such flow is produced by the balance of the Coriolis force (q.v.; caused by the Earth’s rotation) and the pressure-gradient force.
What causes the currents to go in opposite directions?
distance around the outside of a circle. the result of Earth’s rotation on weather patterns and ocean currents. The Coriolis effect makes storms swirl clockwise in the Southern hemisphere and counterclockwise in the Northern Hemisphere.
Where will the winds tend to be more Geostrophic?
The geostrophic wind is the wind flow that occurs in the middle latitudes aloft in the troposphere. The winds have a more difficult time obtaining geostrophic balance in the equatorial latitudes since the Coriolis force is weak.
What are Geotropic winds Class 11?
What are the geotrophic winds? Answer: The velocity and direction of the. wind are the net result of the wind generating forces. The winds in the upper atmosphere, 2-3 km above the surface, are free from frictional effect of the surface and are controlled mainly by the pressure gradient and the Coriolis force.
What causes geostrophic currents?
This occurs because the Earth is rotating. The rotation of the earth results in a “force” being felt by the water moving from the high to the low, known as Coriolis force. The Coriolis force acts at right angles to the flow, and when it balances the pressure gradient force, the resulting flow is known as geostrophic.
Is jet stream a geostrophic wind?
The Jet Stream is a geostrophic wind blowing horizontally through the upper layers of the troposphere, generally from west to east, at an altitude of 20,000 – 50,000 feet. Jet Streams develop where air masses of differing temperatures meet. So, usually surface temperatures determine where the Jet Stream will form.
How deep do Ekman spirals go?
100 to 150 meters
This makes a spiral of moving water 100 to 150 meters (330 to 500 ft) deep called an Ekman spiral. The average direction of all this turning water is about a right angle from the wind direction. This average is Ekman transport. The Ekman spiral and Ekman transport are named for Swedish scientist V.
What is a geostrophic wind?
Geostrophic windsexist in locations where there are no frictional forces and the isobars are striaght. However, such locations are quite rare. Isobarsare almost always curved and are very rarely evenly spaced. This changes the geostrophic winds so that they are no longer geostrophic but are instead in gradient wind balance.
What are the geostrophic equations?
The geostrophic equations are a simplified form of the Navier–Stokes equations in a rotating reference frame. In particular, it is assumed that there is no acceleration (steady-state), that there is no viscosity, and that the pressure is hydrostatic. The resulting balance is (Gill, 1982):
What is geostrophic flow?
Geostrophic flow may be either barotropic or baroclinic. A geostrophic current may also be thought of as a rotating shallow water wave with a frequency of zero.
What is an example of a geostrophic current?
The major currents of the world’s oceans, such as the Gulf Stream, the Kuroshio Current, the Agulhas Current, and the Antarctic Circumpolar Current, are all approximately in geostrophic balance and are examples of geostrophic currents.