This title appears in the Scientific Report : 2003 

A Generalized Form of Lait's Modified Potential Vorticity
Müller, R.
Günther, G.
Stratosphäre; ICG-I
Journal of the atmospheric sciences, 60 (2003) S. 2229 - 2237
Boston, Mass. American Meteorological Soc. 2003
2229 - 2237
Journal Article
Chemie und Dynamik der Geo-Biosphäre
Journal of the Atmospheric Sciences 60
Please use the identifier: in citations.
Please use the identifier:<2229:AGFOLM>2.0.CO;2 in citations.
Ertel's potential vorticity P is in widespread use as a diagnostic of dynamical processes in the stratosphere. For a variety of applications, however, the exponential increase of P with altitude is problematic. For this reason, Lait proposed a modified potential vorticity Pi(L) where a physically meaningful scaling is introduced that removes much of the altitude dependence of P. Here a generalized form of Pi(L) is proposed by introducing an additional degree of freedom in the scaling. This generalized modified potential vorticity Pi(g) possesses the same conservation properties as Pi(L) itself and as the classic potential vorticity P but can be adjusted more closely to the specific situation under investigation. Comparison, over a large altitude range in the stratosphere, of fields of Pi(g) with dynamical measures of the polar vortex edge and with observations of the long-lived trace gas N2O shows that Pi(g) constitutes a more intuitively interpretable quantity than Pi(L).