The practical uses of Q- G theory in daily analysis! Lab 14 Anthony R. Lupo Atms 4320

The practical uses of Q-G theory in daily analysis! Classical midlatitude cyclones and anticyclones: Cyclones form along frontal boundaries when an upper air disturbance interacts with this zone. (Norweigan model 1920’s, Eady 1947, Charney 1949) Developing cyclones (energetically active) tilt toward the west as they develop.

The practical uses of Q-G theory in daily analysis! The surface cyclone (developing) is warm core, thus it will open up with height as a result of thermal wind balance. Upper air cyclonic vorticity advection superimposed over the surface low, then increases with height contributing to cyclone development.

The practical uses of Q-G theory in daily analysis! When the wave becomes “vertically stacked”, the vorticity advection forcing is located out ahead of the surface cyclone and no longer contributes to cyclogenesis. AVA contributes to cyclolysis. These arguements can be used in reverse to discuss surface anticyclogenesis (even block development).

The practical uses of Q-G theory in daily analysis! Temperature advections: Using the Sutcliffe arguments we discussed how temperature advections contribute to cyclone development. These typically aid in the development of cyclones. Typically important in the 850 hPa to 700 hPa level.

The practical uses of Q-G theory in daily analysis! Can upper tropospheric temperature advections contribute to surface cyclogenesis? Yes. Advection is the result of wind speeds and temperature gradients, thus with strong wind speeds and weak advections, these can contribute to surface cyclone development. Themodynamic forcing, where in the vertical do we get the best “bang’ for your buck? Down low or up high?

The practical uses of Q-G theory in daily analysis! Down low of course! Draw vertical motion and divergence/convergence profiles! (See also, Rausch and Smith, 1996, MWR, p. 875) Table 1, derived from the double integral in the Z-O equation (thermal terms).

The practical uses of Q-G theory in daily analysis! nPressure levelWeight

The practical uses of Q-G theory in daily analysis! Atmospheric stability: acts as a “governor” on cyclogenesis! (Talk about ‘S  ’) term. Also, Friction term!

The practical uses of Q-G theory in daily analysis! The End!