Wind & Atmospheric Motion Flashcards
What is Wind?
Vertical motion dominated by forced and free convection
What is another name for the approximation wind?
The geostrophic wind
Describe the Coriolis force?
Places travel quicker at the equator where there is no Coriolis, turns Right in the Northern Hemisphere and to the Left in the Southern Hemisphere
What is the Pressure Gradient?
Change in pressure/change in distance
What does a high change in pressure in a short space of time represent?
A large pressure gradient and a high wind feel
What is sub-geostrophic flow?
Low pressure flow, lower than the isobars suggest and a decreased velocity
What is the super-geostrophic wind?
High pressure flow, higher than the isobars suggest and an increase in velocity
What is the impact of friction at the Earth’s surface?
It slows the wind down, which destroys the geostrophic balance
Which two factors must equal for the geostrophic wind?
Pressure gradient force (pgf) and Coriolis (co)
What is the Pressure Gradient Formula?
dP/dN
where: dP = difference in pressure and dN = change in distance
What is the Pressure Gradient Force Formula?
1/p x dP/dN
What is the Coriolis Parameter?
2WVSin(LAT)
where: W = angular velocity of the earth, V=velocity of a moving body and LAT = position on the Earths Surface
What is the Geostrophic Wind Equation ?
Vg = (1/f x p) x (dP/dN) where p = density and f=Coriolis parameter
When looking at curved flow which factors can be changed in the Coriolis parameter?
Velocity if this decreases Co decreases so the wind can turn
How does angular velocity vary across the Earth?
It is 90 degrees at the poles where the Earth is spinning and 0 degrees at the equator where the Earth is rotating
