Table Of Contents

This Page

04.25.2013: LPV analysis of exp33_sponge with twice the temporal resolutionΒΆ

Here, I re-perform the LPV analysis for 5 trajectories done in this note but using 1/2-day instead of 1-day outputs. No major changes are found.

Using exp20 and exp21 for which the LPV analysis is working (that is, the error in the PV balance is much weaker than the genuine PV changes), we found that the LPV analysis is accurate within 1e-12/1e-11 1/(m.s).

The PV changes that we obtain in Fig. 2 are in the order of 1e-10/1e-9 1/(m.s) so that the LPV analysis should be accurate enough to see that. This suggests that the model genuinely does not satisfy the constraint that PV should be balanced along parcel trajectories at least over several cycles. [The only way that conclusion is not true is if the accuracy of the LPV analysis changes also with the regime. I doubt that. Furthermore, the error was the same in two different simulations, exp20 and exp21, although any difference may be subtle].


Figure 1: Trajectories over 175 days in exp33_sponge: using 1/2-day output (plain and dash) and 1-day output (circles).


Figure 2: LPV analysis for the 5 trajectories highlighted in Fig. 1 using snapshots (plain) or 1-day averages (dash) with 1/2-day output or snapshots using 1-day output (circles).

The LPV analysis was done with LPV_analysis_all_time_script.m producing the Matlab file LPV_analysis_alltime_d4015d4215_8E11E_30N_mid_delta_tday_0_5_exp33_sponge.mat, all in RESEARCH/MODELISATION/HIM/studies/PV_and_dissipation/forced_damped_wave/exp33_sponge/ on the main disk on ipu1.