Analysis tools for looking at long swells in SWOT "unsmoothed" data and working with SWOT-derived swell spectra. Some example illustrations can be found in these videos: https://www.youtube.com/playlist?list=PLm1sPhvTQhOxMjglmUjAyB28bSM45C2eQ
Main contributors: Fabrice Ardhuin, Marine De Carlo, Taina Postec, Beatriz Molero, Adrien Nigou
These tools have been used for the following papers:
http://dx.doi.org/10.13140/RG.2.2.32296.17925 Phase-resolved swells across ocean basins in SWOT altimetry data: revealing centimeter-scale wave heights including coastal reflection
https://www.pnas.org/doi/10.1073/pnas.2513381122 Sizing the largest ocean waves using the SWOT mission
https://www.nature.com/articles/s41467-026-71541-6 Swell-driven bursts of 26 s and 16 s seismic spectral peaks in the Gulf of Guinea
https://doi.org/10.22541/essoar.15005336/v1 SWOT sea level noise at wavelengths under 10~km: implications for wave detection and analysis
The most simple script (using surface elevation data) is "swot_swell_fig1.ipynb", it takes a sample of SWOT "unsmoothed" data and computes a wave spectrum from it. If you have co-located wave model output, it will also compare model and SWOT data.
- download the spectra from AVISO (August 2023 to June 2024): https://www.aviso.altimetry.fr/en/data/products/windwave-products/swot-karin-level-3-wind-wave-product.html
- compute your own spectra from SWOT L2 or L3 surface elevation maps: use the notebook swot_compute_spectra_light_multi_tracks.ipynb Note that this produces very similar files ... but not exactly the same. More later here about differences.
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plot_one_spectrum.ipynb : this notebook just plots one spectrum
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plot_spectra_slider.ipynb : interactive tool to plot SSH and corresponding spectra along the track. Also displays 250 m grid distortions due to waves.
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L3_fit_one_track_LandH.ipynb : plots parameters for an entire track but also includes an interactive plot of single spectra (using a widget slider)
- surfboard_areas.ipynb : computes nonlinear SWOT mapping for academic wave group cases
- surfboard_realcases.ipynb : computes nonlinear SWOT mapping for simulated wave spectra
- checking_obp_filter.ipynb : makes a few plots of the OBP filter and PTR effects.
- TO BE ADDED LATER: analysis of both 1D and 2D noise, with 1D analysis based on Zhang and Callies.
- noise_analysis_2D_only_20km_L2_med.ipynb : produces an netcdf file that contains 2D noise information and related model data
- noise_analysis_2D_only_20km_L2_med_from_segments.ipynb : analysis of SWOT 2D noise information
- plot_watershed.ipynb : this works with version 2 of the CNES L3 product, but also with version 2.1_light (with X-spectra phase included): here are examples here https://drive.google.com/drive/folders/1Eu_KRgLw6uHMKNFgUUJ6n6w5gY_CMNVB?usp=drive_link
For some of the other notebooks, you may need to download these data sets:
https://www.seanoe.org/data/00885/99739/ Spotter buoy data for storm "Rosemary"
https://www.seanoe.org/data/00886/99783/ (this is our model hindcast only for June 2023, the full year 2023 and more is available on datarmor)
(or if you are working on our datarmor cluster, here they are: ) /home/datawork-WW3/PROJECT/SWOT
- Balanced_extraction_2D_v1.ipynb: adaptation of a notebook by Zhang for figures 1 and 2 in noise paper
git clone --quiet https://github.com/ardhuin/swellSWOT