Add global Look-Up Table (LUT) of physiological ratios access and co-localisation method

[gmaze]

The "Global Look-Up Table of Physiological Ratios for the Real-Time Adjustment of Chlorophyll-a Fluorescence within the OneArgo Framework" netcdf file is on its to be published at Seanoe under 10.17882/105732.

This dataset provides a global Look-Up Table (LUT) of physiological ratios for the real-time adjustment of chlorophyll-a fluorescence measured by biogeochemical Argo (BGC-Argo) profiling floats. The physiological ratios aim to account for the global variability in the relationship between fluorescence and chlorophyll-a concentration, as influenced by phytoplankton physiology.

This is a small netcdf file used mainly in RTQC for CHLA.

It could be interesting for expert users to have an easy access to the file (packaged within argopy maybe) and run some colocalisation with a BGC float to be analysed for QC, replay RTQC or dev DMQC.

A possible API could look like this:

from argopy import ArgoFloat

af = ArgoFloat(1902605)  # Some BGC float with CHLA sensor

# Colocate physiological_ratio along the float trajectory
af.colocate.physiological_ratios()  # returns a (lat,lon,ratio) tuple

The method could also be accessible as a ds.argo extension., and applied to some xarray dataset of multi profile files:

from argopy import ArgoFloat

af = ArgoFloat(1902605)  # Some BGC float with CHLA sensor
ds = af.open_dataset('Sprof')

# Colocate physiological_ratio along the float trajectory
ds.argo.colocate.physiological_ratios()  

Or to some specific profile:

from argopy import ArgoIndex, gdacfs

# Get a profile dataset from some BGC float with CHLA sensor
idx = ArgoIndex(index_file='bgc-s').query.wmo_cyc(1902605, 12)
ds = gdacfs(cache=True).open_dataset(idx.read_files()[0])

# Colocate physiological_ratio for this profile
ds.argo.colocate.physiological_ratios()

In these scenario, ratios would be added to the xarray dataset as a new variable