What is the Mesoscale? Flashcards
For flow to be geostrophic, the Ordinary Rossby Number (advective) needs to be ____
small
What is the equation for the Rossby Number?
R0 = U / Lf
where U = velocity of the fluid
L = horizontal length scale
f = Coriolis parameter
R0 «_space;1 for ____ flow
geostrophic (rotationally balanced)
R0 is essentially a ratio of the ____ ____ and the ____ parameter
local acceleration (U/L) and Coriolis parameter
Name 3 ways to make R0 larger?
1) decreasing the size of a system (decrease L)
2) decrease the latitude (decrease value of f)
3) Increasing the wind speed (increase U)
A system is less likely to conform to geostrophic balance (larger R0) if? (3 things)
1) The system is small
2) A system is located at low latitudes (closer to the equator)
3) system contains strong winds
Rw stands for what?
Wave Rossby Number
What is the equation for Rw?
Rw = c / Lf
where: c = gravity wave speed
L = horizontal length scale
f = Coriolis parameter
What is the Lr?
Rossby Radius of Deformation
What is the equation for Lr?
Lr = c / f
c = gravity wave speed as a function of static stability (buoyancy) of the fluid f = Coriolis parameter
The Rossby Radius of Deformation is the horizontal scale at which ____ effects become as important as ___ effects
rotation | buoyancy
When the scale of a weather system is ____, buoyancy dominates over rotation
smaller
When the scale of a weather system is ___ than Lr, rotation dominates over buoyancy
larger
When the scale of a weather system is smaller than Lr, this defines the ____, or smaller
mesoscale
When the scale of a weather system is smaller than Lr, the ___field adjusts to the ____ field
mass | wind
When the scale of a weather system is smaller than Lr, ____ ____ dominate over ____ ____
gravity waves | geostrophic flow
When the scale of a weather system is larger than Lr, ___ ___ dominates over ___ ____
geostrophic flow | gravity waves
When the scale of a weather system is larger than Lr, the ____ field responds to the ___ field
momentum (wind) | mass (height or pressure)
The maximum size of the mesoscale is essentially whatever the ____ is at that Location
Rossby Radius of Deformation
What are the Lr values of:
1) mid-lat convection
2) equatorial convection
3) near-equatorial convection
4) tropical cyclone
1) Lr ~ 300 km
2) Lr ~ infinity
3) Lr ~ 1500 km
4) Lr ~ 5 km
____ ____ in a barotropic model is a product of rossby wave generation in the tropical upper troposphere
Tropical Plumes
With a broad trough, (L ___ Rossby Radius), and ___ balance dominates over ___
L>Rossby Radius
rotational balance dominates over buoyancy
With a contracting trough, L ___ rossby radius, and rotational and buoyancy ____
L~rossby radius
rotational and buoyancy equal
With sharp trough, L __ rossby radius, ___ dominates over ____. A ___ ____ forms
L < rossby radius
buoyancy dominates over rotation
Tropical plume forms
