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ESA Sea State Climate Change Initiative (Sea_State_cci): Global remote sensing multi-mission along-track significant wave height from altimetry, L2P product, version 3

Update Frequency: Not Planned
Latest Data Update: 2022-10-05
Status: Completed
Online Status: ONLINE
Publication State: Citable
Publication Date: 2022-10-10
DOI Publication Date: 2022-10-11
Download Stats: last 12 months
Dataset Size: 709.37K Files | 189GB


The ESA Sea State Climate Change Initiative (CCI) project has produced global multi-sensor time-series of along-track satellite altimeter significant wave height data (referred to as Level 2P (L2P) data) with a particular focus for use in climate studies.

This dataset contains the Version 3 Remote Sensing Significant Wave Height product, which provides along-track data at approximately 6 km spatial resolution, separated per satellite and pass, including all measurements with flags, corrections and extra parameters from other sources. These are expert products with rich content and no data loss.

The altimeter data used in the Sea State CCI dataset v3 come from multiple satellite missions spanning from 2002 to 2022021 (Envisat, CryoSat-2, Jason-1, Jason-2, Jason-3, SARAL, Sentinel-3A), therefore spanning over a shorter time range than version 1.1. Unlike version 1.1, this version 3 involved a complete and consistent retracking of all the included altimeters. Many altimeters are bi-frequency (Ku-C or Ku-S) and only measurements in Ku band were used, for consistency reasons, being available on each altimeter but SARAL (Ka band).

Citable as:  Piollé, J.-F.; Dodet, G.; Quilfen, Y.; Schwatke, C.; Passaro, M.; Quartly, G.; Thibaut, P. (2022): ESA Sea State Climate Change Initiative (Sea_State_cci): Global remote sensing multi-mission along-track significant wave height from altimetry, L2P product, version 3. NERC EDS Centre for Environmental Data Analysis, 11 October 2022. doi:10.5285/8cb46a5efaa74032bf1833438f499cc3.
Abbreviation: Not defined
Keywords: CCI, Sea State, Significant Wave Height


Previous Info:
No news update for this record
Previously used record identifiers:
No related previous identifiers.
Access rules:
Public data: access to these data is available to both registered and non-registered users.
Use of these data is covered by the following licence: When using these data you must cite them correctly using the citation given on the CEDA Data Catalogue record.
Data lineage:

Data was produced by the ESA Sea State CCI team at Ifremer and was transferred to CEDA as part of the ESA CCI Open Data Portal project.

Data Quality:
The data were quality checked and compared to in situ reference data. For more details on the validation process, refer to the product user guide.
File Format:
Data are in NetCDF format

Process overview

This dataset was generated by a combination of instruments deployed on platforms and computations as detailed below.

Computation Element: 1

Title Derivation of ESA Sea State Climate Change Initiative (Sea_State_cci): Global remote sensing multi-mission along-track significant wave height from altimetery, version 3 datasets
Abstract For information on the derivation of the Sea_State_cci Global remote sensingmulti-mission along-track significant wave height from altimetery version 3 products please see the product user guide.
Input Description None
Output Description None
Software Reference None
Output Description


  • units: m s-1
  • long_name: 10 metre U wind component
  • var_id: wind_speed_model_u
  • units: m s-1
  • long_name: 10 metre V wind component
  • var_id: wind_speed_model_v
  • units: K
  • long_name: 2 metre temperature
  • var_id: surface_air_temperature
  • units: m
  • long_name: Ku band adjusted significant wave height
  • standard_name: sea_surface_wave_significant_height
  • var_id: swh_denoised
  • units: dB
  • var_id: sigma0
  • standard_name: surface_backwards_scattering_coefficient_of_radar_wave
  • long_name: Ku band backscatter coefficient
  • units: m
  • var_id: swh
  • standard_name: sea_surface_wave_significant_height
  • long_name: Ku band significant wave height
  • units: m
  • standard_name: sea_surface_height_above_geoid
  • var_id: mdt
  • long_name: Mean dynamic topography
  • units: Pa
  • var_id: surface_air_pressure
  • long_name: Mean sea level pressure
  • standard_name: air_pressure_at_mean_sea_level
  • units: degree
  • long_name: Mean wave direction
  • var_id: mean_wave_direction_model
  • units: degree
  • var_id: primary_swell_direction_model
  • long_name: Mean wave direction of first swell partition
  • units: s
  • long_name: Mean wave period
  • var_id: mean_wave_period_model
  • units: s
  • var_id: peak_wave_period_model
  • long_name: Peak wave period
  • units: m
  • var_id: swh_rms
  • long_name: RMS of the Ku band significant wave height (from high frequency measurements)
  • units: dB
  • var_id: sigma0_rms
  • long_name: RMS of the high frequency Ku band backscatter coefficient
  • units: m
  • standard_name: sea_surface_height_above_sea_level
  • var_id: sla_unfiltered
  • long_name: Sea level anomaly not-filtered not-subsampled with dac, ocean_tide and lwe correction applied
  • units: m
  • var_id: swh_model
  • long_name: Significant height of combined wind waves and swell
  • units: m
  • var_id: primary_swell_swh_model
  • long_name: Significant wave height of first swell partition
  • units: m
  • long_name: best estimate of significant wave height standard error
  • var_id: swh_uncertainty
  • long_name: consolidated instrument and ice flags
  • var_id: swh_rejection_flags
  • units: m
  • long_name: distance to nearest coast
  • var_id: distance_to_coast
  • units: m
  • var_id: swh_noise
  • long_name: high-frequency noise attached to swh_adjusted
  • units: 1
  • var_id: sigma0_num_valid
  • long_name: number of high frequency valid points used to compute Ku band backscatter coefficient
  • units: 1
  • var_id: swh_num_valid
  • long_name: number of high frequency valid points used to compute Ku band significant wave height
  • units: m
  • var_id: bathymetry
  • long_name: ocean depth
  • standard_name: sea_floor_depth_below_mean_sea_level
  • long_name: quality of Ku band significant wave height measurement
  • var_id: swh_quality
  • units: kg m-2
  • standard_name: atmosphere_cloud_liquid_water_content
  • long_name: radiometer liquid water content
  • var_id: total_column_liquid_water_content_rad
  • units: 1
  • standard_name: sea_ice_area_fraction
  • long_name: sea ice fraction
  • var_id: sea_ice_fraction
  • units: m
  • var_id: swh_denoised_uncertainty
  • long_name: uncertainty attached to swh_adjusted
  • units: m s-1
  • standard_name: wind_speed
  • var_id: wind_speed_alt
  • long_name: wind speed from Ku band altimeter, as in GDR

Co-ordinate Variables

  • units: degree_north
  • standard_name: latitude
  • var_id: lat
  • units: degree_east
  • standard_name: longitude
  • var_id: lon
  • standard_name: time
  • var_id: time
  • units: seconds
  • long_name: measurement time
Temporal Range
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Geographic Extent