After a careful reading of those papers, especially Holliday and McIntyre (1981, JFM), McIntyre and Shepherd (1987, JFM), Roullet and Klein (2009, JFM), Kang and Fringer (2010, JPO), and Huang and Nakamura (2016, JAS), I am pretty sure that local available potential energy (LAPE) is an vertical equivalence to impulse-Casimir wave activity (ICWA) in the horizontal plane. In Huang and Nakamura (2016, JAS), ICWA, and hence LAPE, is clearly demonstrated to be different from local wave activity (LWA). However, in the vertical plane where stratification is usually strong enough to suppress vertical displacement, LWA is quite similar to LAPE in this small-amplitude limit.
So I need to change the calculation of local APE from that of LWA. Local APE is conceptually equivalent to ICWA.
After a careful reading of those papers, especially Holliday and McIntyre (1981, JFM), McIntyre and Shepherd (1987, JFM), Roullet and Klein (2009, JFM), Kang and Fringer (2010, JPO), and Huang and Nakamura (2016, JAS), I am pretty sure that local available potential energy (LAPE) is an vertical equivalence to impulse-Casimir wave activity (ICWA) in the horizontal plane. In Huang and Nakamura (2016, JAS), ICWA, and hence LAPE, is clearly demonstrated to be different from local wave activity (LWA). However, in the vertical plane where stratification is usually strong enough to suppress vertical displacement, LWA is quite similar to LAPE in this small-amplitude limit.
So I need to change the calculation of local APE from that of LWA. Local APE is conceptually equivalent to ICWA.