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07.16.11: Lagrangian PV analysis in exp2_tΒΆ

The Lagrangian analysis is performed for exp2_t, a simulation that is similar to all previous ones forced with a 100-day periodic plunger. In this simulation, however, the velocity field in the middle layer is about 10-20 cm/s and potential vorticity (PV) homogenization occurs in the middle layer.

The first animation shows the Lagrangian PV balance over the entire domain. The upper panel is Q-Q0, the increase in PV for each parcel since the first day of the analysis (day 2125). The lower panel is the time integral of the PV dissipation term. The two Lagrangian quantities are plotted at the initial position of each parcel. Thus, in this animation, we know the PV change underwent by a parcel that started at a certain position but we do not know where in the domain that PV change occurs (because we do not know where the parcel is).

The second animation provides this missing information. The upper left panel shows the PV dissipation term (unit of PV per second) together with 3 particular trajectories. The other panels show the PV balance along the trajectory of these parcels.

The first animation shows that, besides very near the western boundary, the PV balance is satisfied everywhere. The second animation shows some interesting dynamics. It shows that large PV changes occur mainly along the western boundary or around eddies. Next step is to perform a similar study with a simulation of a two-gyre wind-driven circulation.

The animations were produced with anim/anim_script.m and anim_2/anim_script.m in RESEARCH/MODELISATION/HIM/studies/diss_train_of_eddies/exp2/exp2_t/ on the main disk.