Final Exam Spring Flashcards
Scaling analysis for synoptic scale motion outside the planetary boundary layer shows these motions to be approximately in Geostrophic and hydrostatic balance
True
Geostrophic balance is a force balance involving the vertical component of the pressure gradient force and gravity
False
When using pressure as the vertical component (isobaric conditions), the Geostrophic wind is expressed using the horizontal pressure gradient
False
If the thermal wind is 0 (vt =0) then the atmosphere is Barotropic
True
Deformation, acting by itself in the horizontal plane, can bring about a change in the shape of an air parcel in the horizontal plane
True
The mass flux provides a measure of the amount of mass moving through an area in a given period of time
True
Surface Pressure tendency: If there is a net positive divergence (more positive divergence than negative divergence) in the column from the surface to the top of the atmosphere, the surface pressure will increase
False
Circulation is a microscopic measure of rotation in a fluid at a single point in space
False
Absolute vorticity is the sum of curvature vorticity and shear vorticity
False
If the curvature vorticity associated with a flow pattern is greater than zero, streamline curve in a clockwise or anticyclonic sense
False
The absolute vorticity equation can have a divergence term, a tilting/twisting term, and a baroclinic/solenoid term appear on the right hand side of the equation
True
When scaled for synoptic scale motion, the absolute vorticity equation will only have a divergence term appearing on the right hand side of the equation
True
The velocity potential “chi” is used to represent the rotational part of the flow
False
Rossby waves are the result of absolute vorticity being conserved following an air parcel
True
The perturbation method for solving the governing equations involves approximating all meteorological variables contained in the equations in terms of only their background average value
False
Winds in the planetary boundary layer where friction is present tend to be subgeostrophic with the wind blowing across the isobars/height contours towards low pressure
True
When we look at the concept of stability in the atmosphere, the issue we are concerned with is whether a disturbance will amplify (grow) or damp out (dissipate) with time
True
The static stability parameter (Sp) we derived in class simply the difference between the dry Adiabatic lapse rate and the saturated (moist) Adiabatic lapse rate
False
The atmosphere is statically stable when the environmental lapse rate is greater than the dry adiabatic lapse rate
False
The release of latent heat under saturated conditions allows a statically stable atmosphere to become unstable
True
Cyclogenesis
The formation and/or the strengthening of a low pressure system center at the surface
What can cyclogenesis be thought of as
Dynamic instability
What exists when cyclogenesis is occurring
A disruption of geostrophy
Stages of formation with CISK
Conditional instability-> Initial disturbance -> Latent Heat Release -> Upper- Level Divergence -> surface pressure falls
Stages of formation WISHE
Conditional instability-> Initial disturbance -> Latent Heat Release -> Upper- Level Divergence -> surface pressure falls -> faster surface winds -> greater surface moisture flux
What drives the net divergence tray leads to cyclogenesis in the midlatitudes
Baroclinic instability
Baroclinic vorticity
Thermal advection’s interacting with vorticity effects are the important processes
Main regions of cyclogenesis
Gulf coast/ east coast cyclogenesis
Lee (or east side) of the Rockies
Potential vorticity
It’s defined as the absolute vorticity associated with an isolate volume of air bounded top and bottom by isentropic surfaces and is divided by the depth of the volume
secondary ageostrophic circulations
- When the atmosphere deviates from Geostrophic balance and acceleration associated with ageostrophic motion results
- Divergence associated with the ageostrophic motion leads to vertical motion producing this
How does WISHE modifies CISK theory?
WISHE adds sfc. Moisture flux that is proportional to the surface wind speed and the increased surface moisture flow flux destabilizes the atmosphere. The main issue with CISK is that it suggests that tropical cyclones will form over land, the reason for WISHE’s existence
