Parameters used META 3.2 AVISO

[SusanaMSilva]

Hi!

I have been trying to reproduce the META 3.2 eddy tracking results to make sure that everything is working properly since my objective is to use the py-eddy-tracking on my ROMS model, but I am getting less tracked eddies when compared to the AVISO product.

I used the parameters below, as they were the ones referred in the manual:

 g = RegularGridDataset(grid_name, lon_name, lat_name)
g.lanczos_high_filter('adt', 700, order=1)
 
a, c = g.eddy_identification('adt','ugos',
    'vgos',  # Variables used for identification
    date,  # Date of identification
    0.002,  # step between two isolines of detection (m)
    pixel_limit=(5, 1000),  # Min and max pixel count for valid contour 
    shape_error=70,  # Error max (%) between ratio of circle fit and contour
)

Also, I'm using maps of ADT with a 0.25 resolution, which I think were the same used.
Do I need to add other parameters in the eddy identification? And also, can I change the minimum amplitude?

I then used the eddy traking.yaml:

PATHS:
 # Files produced with EddyIdentification
 FILES_PATTERN: /py-eddy-tracker/share/Anticyclonic_*.nc
 # Path to save outputs
 SAVE_DIR: 'py-eddy-tracker/share/'

# Number of consecutive timesteps with missing detection allowed
VIRTUAL_LENGTH_MAX: 3
# Minimal number of timesteps to considered as a long trajectory
TRACK_DURATION_MIN: 10

CLASS:
  MODULE: py_eddy_tracker.featured_tracking.area_tracker
  CLASS: AreaTracker

Can you help me with this?

Thank you,
Susana Silva

[AntSimi]

Before to compare tracking, did you have same identification?

[SusanaMSilva]

Hi,

In the manual it only says shape error ≤ 70%, amplitude ≤ 0.4cm, only one extremum, 5 ≤ Npixel ≤ 1000 (I guess that this Npixel limits the existence of one extreme?), but I don't know which shape error was used exactly in the META 3.2 identification.
Also, I don't know how can I modify the amplitude, if 0.4cm is not the default.

The ADT maps were filtered like it says in the META manual, using a lanczos_high_filter 1st order with a 700km cut off. If I use this function do I still have to subtract the result from the original maps? From what I understood, the result is already the filtered map.

So I guess there are some parameters that are different from those that I used and that's why I was wondering if you can tell me exactly the parameters used to obtain the results of META 3.2

Thank you again.