SCUBA performs spectral/statistical analysis of along-track and gridded dataset, as well as spectral statistical comparison between two fields (e.g., along-track vs grid, grid vs grid).

Table of contents

• Table of contents
• Structure of SCUBA
• Usage and Background
• First step with SCUBA
  • Running test cases
  • Visualisation of the results
• Authors and Contributors

Structure of SCUBA

                                        SCUBA
                                          |
            +--------------------+----------------+---------------------+
          share                 src           test_case                tools

• share contains information or files for running the program, e.g. the distance from closest land point (needed for coastal editing) or altimeter mission information
• src contains the python scripts to perform the analysis
• test_case provides test cases to test the program
• tools includes scripts to display spectrum, resolution and spectral Taylor Diagram

Usage and Background

• scuba_alongtrack.py performs spectral analysis on along-track data or between along-track and gridded data
• scuba_grid.py performs spectral analysis on gridded data or between two gridded data
• scuba_tide_gauge.py performs spectral analysis on tide gauge and gridded data timeseries
• scuba_mooring.py performs spectral analysis on mooring and gridded data timeseries

The program is structured as follow:

• 1- reading the dataset

• 2- computing segment (along-track, or zonal or meridional) database

Example alongtrack direction

Example zonal direction

Example meridional direction

• 3- performing spectral analysis in boxes by selecting all the segments of the database found within the box

• 4- gridding the results

• 5- writing netCDF output

First step with SCUBA

Running test cases

---

 >> cd test_case/
 >> ./run_example.x

This test cases performs spectral analysis on altimeter maps and along-track data. For more detail on the analysis parameters see *.yaml parameter files.

Goodies & Visualisation of the results

---

 >> cd tools

The tools folder contains several scripts for additional diagnostics (autocorrelation, resolution, ...):

• compute_autocorrelation_alongtrack.py computes autocorrelation functions from along-track analysis
• compute_autocorrelation_tg_mooring.py computes autocorrelation functions from tide-gauges or mooring analysis
• compute_effective_resolution_alongtrack.py computes map effective spatial resolution from along-track/map analysis
• compute_effective_resolution_tg_mooring.py computes map effective temporal resolution from tide-gauges or mooring analysis
• compute_effective_resolution_transfer_function.py computes filter transfer function
• compute_resolution_limit_alongtrack.py computes along-track resolution as defioned in Dufau et al. (2016)
• compute_skill_score.py computes skill score (under dev)
• compute_variance.py computes variance
• display_scuba_alongtrack.py shows spectral analysis for along-track
• display_scuba_grid.py shows spectral analysis for grids
• plot_spatial_resolution.py shows spatial resolution
• plot_temporal_resolution.py shows temporal resolution

Some examples below:

 >> cd test_case/
 >> python ../tools/compute_effective_resolution_alongtrack.py psd_alongtrack_direction.nc effective_resolution_alongtrack.nc
 >> python ../tools/plot_spatial_resolution.py effective_resolution_alongtrack.nc

 >> python ../tools/compute_effective_resolution_tg_mooring.py psd_tide_gauge.nc effective_resolution_tg.nc
 >> python ../tools/plot_temporal_resolution.py effective_resolution_tg.nc

 >> python ../tools/compute_effective_resolution_tg_mooring.py psd_mooring.nc effective_resolution_mooring.nc
 >> python ../tools/plot_temporal_resolution.py effective_resolution_mooring.nc

 >> python ../tools/display_scuba_alongtrack.py psd_alongtrack_direction.nc

Authors and Contributors

• Maxime Ballarotta, Clément Ubelmann
• Feel free to dive in ...