MAKING A PREDICTION FOR TERM A
In order to diagnose vertical motion from the Q-G Omega Equation, first recall that the Laplacian of a variable is proportional to the negative of its magnitude (assuming sinusoidal properties of waves). For Term A, it is important to remember that the sign of the term is proportional to the negative of ω . Recall that ω (vertical motion) is proportional to –w (vertical velocity). Taking the aforementioned criteria into consideration, it is important to recognize the following:
- If the sum of Term B and Term C is positive , then:
- Conversely, if the sum of Term B and Term C is negative , then:
It should also be noted that:
For large scale disturbances, this response function will span much of the troposphere for a given level of forcing.
For small scale disturbances, this response function will be confined close to the level of forcing.
Q13 – When the sum of Term B and Term C is negative, what is the sign of ω? Is there upward or downward motion?
Q14 – When the sum of Term B and Term C is positive, what is the sign of ω? Is there upward or downward motion?
Q15 – In order for Term A to be positive, what should the sign of the low-level thermal advection be (in the absence of a vertical variation in absolute geostrophic vorticity advection)?
Q16 – In order for Term A to be negative, how should the geostrophic advection of geostrophic absolute vorticity advection vary with height (in the absence of temperature advection)?
ANSWERS TO QUESTIONS