• Section 1: Sutcliffe's development eqn
  • eqn (8.7)
  • associate surface convergence with development
  • obtain 3 forcing terms:
    1. advection of sfc vort. by thermal wind. Important indicator that sfc cyclone moves parallel to the thickness contours
    2. advection of thermal vort by thermal wind. This looks a lot like the development term in the BEBVE. It does same thing here.
    3. "beta" term -- this term bogus. Planetary rotation cannot cause growth of a cyclone.

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• Section 2: Petterssen's development equation
  • eqn (8.10)
  • improves upon Sutcliffe's
    1. the beta term not present
    2. includes diabatic heating: where there is heating, P falls.

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• Section 3: Trenberth's approximation
  • the 2 forcing terms in "Omega" eqn can be expressed in terms of geopotential. So, try to combine them
  • goal is to remove ambiguity of sign of omega when T advection and Vort advection oppose each other.
  • approximate form:
    ( - Omega) ~ (advection of 700 mb level absolute vort. by thermal wind from 1000/500 mb thickness)

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