Final 2024 Flashcards
w
vertical velocity
(T or F) The omega equation is derived from the OG vorticity and thermodynamic equations
True
Compressibility
The physical mechanism of an acoustic (sound) wave
Conservation of potential vorticity
The physical mechanism of a Rossby wave
Buoyancy
the physical mechanism of a gravity wave
If a wave is dispersive, it’s speed depends on
wavelength
(T or F) An extratropical cyclone can be considered to be a type of baroclinic Rossby wave
True
Extratropical cyclones develop due to
baroclinic instability
Which condition will a mid-level ridge grow?
warm advection under the ridge
The speed of the barotropic Rossby wave is determined by:
zonal wind speed, wavelength, latitude
Equation Newton’s 2nd law is based from
Momentum Eq
The equation of State is based from
Ideal Gas Law
Equation Conservation of Mass is based from
Continuity Equation
Equation 1st Law of Thermo is based from
Thermodynamic Eq.
Effective gravity =
Gravity + centrifugal
Changes in wind over time =
PGF + gravity + friction + Coriolis
Time change for a parcel =
Time change at a location - advection
∇ (dot) V
Divergence of wind, divergence
∇T
Gradient of T, spatial change
∇ X V
curl of wind, rotation
-V (dot) ∇T
advection of T
Thermal wind =
hydrostatic + geostrophic
Hypsometric Equation
thickness is proportional to temperature
What is the thickness of an atmospheric layer proportional to?
The average temperature of the layer
What is the simplest explanation for the movement of troughs and ridges?
Vorticity Advection
What can be calculated from vorticity?
winds and the heigh fields can be approximated
What does potential vorticity combine?
QG vorticity and thermodynamics
What does the vertical component of the vorticity vector correspond to?
Horizontal rotation
What is the most important aspect of rotation for synoptic scale flow?
Horizontal rotation
meridional momentum symbol?
v
zonal momentum symbol>
u
Absolute vorticity tendency:
rate of change of the vertical component of absolute vorticity following the flow
What does potential vorticity consider?
both rotation and how mass is distributed relative to the axis of rotation
What kind of relationship is between the height of the column and local stability?
inverse relationship
What can Potential vorticity be considered as?
absolute vorticity multiplied by static stability or absolute vorticity divided by height of the column
Rotation/heigh stays constant with:
incompressible, mass conserving columns
What contributes to relative vorticity?
shear vorticity and curvature vorticity
What can be calculated when conditions are near geostrophic?
winds, vorticity, temperature, vertical velocity, height changes
What is conserved during large-scale conditions?
potential vorticity
What is conserved during non-divergent conditions?
absolute vorticity
what is conserved during non-divergent, no rotation conditions?
Relative vorticity
Potential Vorticity:
the relationship between the divergence/convergence and height of column
Vorticity equation describes:
changes in geopotential on a pressure level
thermodynamic equation describes:
changes in Geopotential between levels
Lows:
positive vorticity (NH)
Highs:
negative vorticity (NH)
Smaller waves =
bigger vorticity
What does the Q-vector describe?
change in gradient of potential temperature following the geostrophic flow
What is the LHS of a traditional Omega Eq?
diff vorticity advection and lap temp advection
What is the LHS of the omega equation in thermal wind form?
vort advection by thermal wind
what is the LHS of the omega equation in Q-vector form?
Divergence of Q-vector
Fourier Series:
can build any well-behaved function out of just sines and cosines
Group velocity and phase velocity:
groups of waves can move at different speeds (and in different directions) than individual waves
Refraction:
changes in the speed of a wave determine its direction as well. If you know what determines the wave speed, you know what determines its directions as well
Dispersive wave:
has a speed that depends on wavelength, Any initial disturbance that is a sum of these waves will lose its structure because all the waves will move away at different speeds (disperse)
Adiabatic compressibility of air is a example of what wave?
acoustic wave
Parcel buoyancy of air is a example of what wave?
gravity waves
conservation of potential vorticity of air is a example of what wave?
Rossby waves
Coriolis force of air is a example of what wave?
inertial oscillations
Buoyancy and the Coriolis force of air is a example of what wave?
inertio-gravity waves
Rossby wave mechanism:
conservation of potential vorticity
Rossby wave speed:
determined by PV gradient and wavenumber
Rossby wave Meteorological importance:
planetary waves, synoptic storms, large-scale orographic forcing, El Niño teleconnections, Sudden Stratospheric Warming (SSW)
Barotropic RW:
horizontal movement at single level
Baroclinic RW:
interaction between different levels, can have horizontal and vertical movement
Speed and direction of RW’s are controlled by:
mean wind, latitude, and wavenumber
Positive feedback for baroclinic instability if:
there is westward tilt with height
Vorticity advection with upper level troughs and ridges can cause
surface level lows and highs to develop