Published a paper on Local Wave Activity Budget!

I’ve published a new paper on Geophysical Research Letters!

Climate dynamicists have derived a conservation relation based on small-amplitude wave assumption for wave activity (A) that describes evolution of Rossby wave packets:

However, only the wave activity flux vector on the RHS has been used to diagnose realistic climate data. A is ill-defined when wave amplitude is large (i.e. ‘of finite-amplitude’). In Huang & Nakamura (2016), we introduced a new theory of wave activity applicable to large waves. We thus can obtain a well-defined A even from real data. This is the first piece of work that compare LHS and RHS of the conservative part of equation above for reanalysis data. This advance allows us to estimate the overall non-conservative contribution (natural/human-induced forcings) to the observed flow.

Major results include:

(1) Our estimation of transient wave activity (top panel) is consistent with previous work (bottom panel, assuming small-amplitude waves) and is better behaving.

(2) We can break down the local wave activity budget at seasonal time-scale.

(3) We can also break down the budget in synoptic time-scale with the use of co-spectral analysis.