SWOT Level 3 Ocean Products

Type of dataset: SWOT Sea Surface Height Data Products (SWOT_L3_SSH)

Digital Object Identifier (DOI) landing pages: 

• SWOT_L3_SSH_Basic_0.3: 10.24400/527896/A01-2023.017 - more metadata 
• SWOT_L3_SSH_Expert_0.3: 10.24400/527896/A01-2023.018  - more metadata

Disclaimer: The current SWOT_L3_SSH v0.3 dataset is derived from the beta pre-validated L2_LR_SSH product (summer 2023 reprocessing release; DOI: https://doi.org/10.24400/527896/A01-2023.015). It is available only for the 1-day CalVal orbit phase, from March 29 to July 10, 2023, and the 21-day Science orbit phase from September 7 to November 21, 2023.

Condition of access: SWOT_L3_SSH v0.3 product is distributed by AVISO to support SWOT mission validation. Note that this product is subject to the standard AVISO+ license agreement.

Contents: The SWOT_L3_SSH product provides ocean topography measurements obtained from the SWOT KaRIn and nadir altimeter instruments, merged into a single variable. The dataset includes measurements from KaRIn swaths on both sides of the image, while the measurements from the nadir altimeter are located in the central columns. In the areas between the nadir track and the two KaRIn swaths, as well as on the outer edges of each swath (restricted to cross-track distances ranging from 10 to 60 km), default values are expected.

Use: SWOT_L3_SSH is a cross-calibrated product from multiple missions that contains only the ocean topography content necessary for thematic research (e.g., oceanography, geodesy) and related applications. This product is designed to be simple and ready-to-use, and can be combined with other altimetry missions. The SWOT_L3_SSH product is a research-orientated extension of the L2_LR_SSH product, distributed by the SWOT project (NASA/JPL and CNES) and managed by the SWOT Science Team project DESMOS.

Description: The SWOT_L3_SSH product is organized in two files:

• Basic L3 SSH (or lightweight), which includes only SSHA (Sea Surface Height Anomaly) and mean dynamic topography.
• Expert L3 SSH (or extended), which includes the backscatter coefficient (sigma0), the mean sea surface and geostrophic currents (absolute and anomalies) in addition to SSHA and mean dynamic topography. It also integrates algorithms, corrections and external models as separate layers.

Citation Basic L3 SSH: "The SWOT_L3_SSH product, derived from the L2 SWOT KaRIn Low rate ocean data products (NASA/JPL and CNES), is produced and made freely available by AVISO and DUACS teams as part of the DESMOS Science Team project". AVISO/DUACS., 2023. SWOT Level-3 SSH Basic (v0.3) [Data set]. CNES. https://doi.org/10.24400/527896/A01-2023.017 

Citation Expert L3 SSH: "The SWOT_L3_SSH product, derived from the L2 SWOT KaRIn low rate ocean data products (NASA/JPL and CNES), is produced and made freely available by AVISO and DUACS teams as part of the DESMOS Science Team project". AVISO/DUACS, 2023. SWOT Level-3 SSH Expert (v0.3) [Data set]. CNES. https://doi.org/10.24400/527896/A01-2023.018 

Further information about the SWOT_L3_SSH product:

• SWOT Level-3 Product Frequently Asked Questions
• Dibarboure et al., Poster at SWOT Science Team 2023, SWOT Level-3 Overview algorithms and examples
• Dibarboure et al., Presentation at SWOT Science Team 2023, SWOT Level-3 Overview algorithms and examples

Tutorials:

• GitHub SWOT community (see https://github.com/SWOT-community/CNES-AVISO)

Geographic coverage: global.