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Description

The SWOT Level 2 KaRIn Low Rate Sea Surface Height Windwave Data Product from the Surface Water Ocean Topography (SWOT) mission provides global sea surface height and significant wave height observations derived from low rate (LR) measurements from the Ka-band Radar Interferometer (KaRIn). SWOT launched on December 16, 2022 from Vandenberg Air Force Base in California into a 1-day repeat orbit for the "calibration" or "fast-sampling" phase of the mission, which completed in early July 2023. After the calibration phase, SWOT entered a 21-day repeat orbit in August 2023 to start the "science" phase of the mission, which is expected to continue through 2025.

The L2 sea surface height data product is distributed in one netCDF-4 file per pass (half-orbit) covering the full KaRIn swath width, which spans 10-60km on each side of the nadir track. Sea surface height, sea surface height anomaly, wind speed, significant waveheight, and related parameters are provided on a geographically fixed, swath-aligned 2x2 km2 grid (Basic, Expert, Windwave). The sea surface height data are also provided on a finer 250x250 m2 "native" grid with minimal smoothing applied (Unsmoothed).

Please note that this collection contains SWOT Version C science data products.

This collection is a sub-collection of its parent: https://podaac.jpl.nasa.gov/dataset/SWOT_L2_LR_SSH_2.0 It provides the "Windwave" file from each L2 SSH product, which includes significant wave height (SWH), normalized radar cross section (NRCS or backscatter cross section or sigma0), wind speed derived from sigma0 and SWH, model information on wind and waves, and quality flags.

Product Summary

Platforms
SWOT
Instruments
KaRIn ,
Jason-class Altimeter ,
AMR ,
DORIS ,
GPSP ,
LRA
Projects
SWOT
Spatial Extent

N: 90 S: -90 E: 180 W: -180

Spatial Resolution
2 Kilometers x 2 Kilometers
250 Meters x 250 Meters
Location
GLOBAL
Coordinate System
CARTESIAN
Granule Spatial Representation
GEODETIC
Temporal Extent
2022-12-16
Data Partner
Jet Propulsion Laboratory, NASA (NASA/JPL) ,
Physical Oceanography Distributed Active Archive Center, Jet Propulsion Laboratory, NASA (NASA/JPL/PODAAC)
Concept ID
C2799465507-POCLOUD
Data State
SUPERSEDED
Number of Files/Granules
19995
Processing Level
2
Published
Updated
Science Keywords
Sea Surface Height ,
Significant Wave Height

Citation

Citation is critically important for dataset documentation and discovery. This dataset is openly shared, without restriction, in accordance with the EOSDIS Data Use and Citation Guidance.

Copy Citation

SWOT. (2024). SWOT Level 2 KaRIn Low Rate Sea Surface Height Data Product [Dataset]. NASA Physical Oceanography Distributed Active Archive Center. https://doi.org/10.5067/SWOT-SSH-2.0 Date Accessed: 2026-08-19

Documents

Publications Citing This Dataset

Filters
Title Year Author Topic
First arctic-wide assessment of SWOT swath altimetry with ICESat-2 over sea ice Muller, Felix L., Dettmering, Denise, Seitz, Florian Sea Ice Elevation, Sea Surface Height, Significant Wave Height
Quantifying Coastal Vulnerability to Sea Level Rise and Land Subsidence Through Satellite Observations and Statistical Modeling Adam, R. N., Vergos, G. S. Sea Surface Height, Significant Wave Height
SWOT based intertidal topography mapping: A standalone method validated Yeasmin, Nushrat, Testut, Laurent, Ballu, Valerie Rivers/Streams, Surface Water Processes/Measurements, Lakes/Reservoirs, Sea Surface Height, Significant Wave Height
Validation of the Surface Water and Ocean Topography (SWOT) KaRIn Sea Level Data Gomez-Enri, J., Arribas-Rodriguez, B., Tejedor, B., Alvarez, O., Gonzalez, C. J., Vignudelli, S. Sea Surface Height, Significant Wave Height
Deriving full-tensor gravity gradients over the Arabian Sea from SWOT Guo, Hengyang, Wan, Xiaoyun Sea Surface Height, Significant Wave Height
Observations of baroclinic tides in the California Current from the SWOT satellite altimeter and in situ data Zaron, Edward D., Waterhouse, Amy F., Wang, Jinbo, Send, Uwe, Lucas, Andrew J. Sea Surface Height, Significant Wave Height, OCEAN TEMPERATURE PROFILES, Sea Surface Height Anomaly (SSHA), Sea Level Anomaly, SURFACE CURRENTS, MESOSCALE EDDIES
Novel Insights on Ocean Internal Waves: Quantitative Surface Cheshm Siyahi, V., Kudryavtsev, V., Chapron, B., Collard, F. Sea Surface Height, Significant Wave Height
SWOT crosstrack error characteristics estimated from observations Jacobs, Gregg, DAddezio, Joseph, Bartels, Brent Sea Surface Height, Significant Wave Height, ABSOLUTE DYNAMIC TOPOGRAPHY, MEAN DYNAMIC TOPOGRAPHY, Mean Sea Surface, Mean Sea Level, Sea Level Anomaly, Sea Surface Height Anomaly (SSHA), Sea Surface Slope
SWOT Mission Validation of Sea Surface Height Measurements at Sub-100 km Wang, Jinbo, Lucas, Andrew J., Stalin, Scott, Lankhorst, Matthias, Send, Uwe, Schofield, Oscar, Kachelein, Luke, Haines, Bruce, Meinig, Christian, Pinkel, Robert, Farrar, J. Thomas, Fu, LeeLueng Sea Surface Height, Significant Wave Height, Sea Surface Height Anomaly (SSHA), Sea Level Anomaly, SURFACE CURRENTS, MESOSCALE EDDIES
Wide-swath satellite altimetry unveils global submesoscale ocean dynamics Archer, Matthew, Wang, Jinbo, Klein, Patrice, Dibarboure, Gerald, Fu, Lee-Lueng Sea Surface Height, Significant Wave Height
SWOT Observations Over Sea Ice: A First Look Kacimi, Sahra, Jaruwatanadilok, Sermsak, Kwok, Ron Sea Ice Elevation, Sea Surface Height, Significant Wave Height
A Multi-Agency Experiment on Internal Wave Energy, Mixing, and Interactions and their Representation in Global Ocean Models and Operational Forecasts Buijsman, Maarten C., Waterhouse, Amy F., Zaron, Edward D., Yadidya, Badarvada, Xu, Chengzhu, Whitley, Victoria, Wenegrat, Jacob O., Wang, Jinbo, Wallcraft, Alan J., Varma, Dheeraj, Tchonang, Babette C., Siyanbola, Oladeji, Shriver, Jay F., Sheremet, Vitalii A., Send, Uwe, Raja, Keshav J., Polzin, Kurt, Ngodock, Hans E., Moulin, Aurelie J., Meiners, Grant, Lucas, Andrew J., Lankhorst, Matthias, Kuehl, Joseph J., Kelly, Samuel M., Kachelein, Luke, Huang, Yonglin, Griffin, Caeli, Girton, James B., Farrar, J. Thomas, Delpech, Audrey, Chen, Zihan, Chassignet, Eric P., Carrier, Matthew J., Bracco, Annalisa, Arbic, Brian K., Andres, Magdalena, Abdulfatai, Mujeeb A. Sea Surface Height, Significant Wave Height, OCEAN TEMPERATURE PROFILES
Assessing submesoscale sea surface height signals from the SWOT mission Zhang, Xihan, Callies, Jorn Sea Surface Height, Significant Wave Height
In Situ Validation of Small-Scale Spatial Variability in Significant Ho, Allison, Wang, Jinbo, Haines, Bruce, Wu, Andy, Stalin, Scott Sea Surface Height, Significant Wave Height
Marine quasi-geoid enhancement from SWOT wide-swath data and its mapping of mean dynamic topography over island areas Wu, Yihao, Baltazar Andersen, Ole, Abulaitijiang, Adili, Wang, Bin, He, Xiufeng, Shi, Hongkai, Luo, Zhicai, Wang, Haihong Sea Surface Height, Significant Wave Height
Observing Interactions Between Waves, Winds, and Currents From SWOT Villas Boas, A. B., Marechal, Gwendal, Bohe, Alejandro Sea Surface Height, Significant Wave Height
Abyssal marine tectonics from the SWOT mission Yu, Yao, Sandwell, David T., Dibarboure, Gerald Sea Surface Height, Significant Wave Height
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Variables

The table below lists the variables contained within a single granule for this dataset. Variables often contain observed or derived geophysical measurements collected from a variety of sources, including remote sensing instruments on satellite and airborne platforms, field campaigns, in situ measurements, and model outputs. The terms variable, parameter, scientific data set, layer, and band have been used across NASA’s Earth science disciplines; however, variable is the designated nomenclature in NASA’s Common Metadata Repository (CMR). Variable metadata attributes such as Name, Description, Units, Data Type, Fill Value, Valid Range, and Scale Factor allow users to efficiently process and analyze the data. The full range of attributes may not be applicable to all variables. Additional information on variable attributes is typically available in the data, user guide, and/or other product documentation.

For questions on a specific variable, please use the Earthdata Forum.

Name Description Units Data Type Fill Value Valid Range Scale Factor Offset
ancillary_surface_classification_flag 7-state surface type classification computed from a mask built with MODIS and GlobCover data. N/A ubyte 255 0 to 6 1 N/A
distance_to_coast Approximate distance to the nearest coast point along the Earth surface. m ushort 65535 0 to 21000 1000 N/A
dynamic_ice_flag Dynamic ice flag for the location of the KaRIn measurement. N/A ubyte 255 0 to 3 1 N/A
heading_to_coast Approximate compass heading (0-360 degrees with respect to true north) to the nearest coast point. degrees ushort 65535 0 to 35999 0.01 N/A
latitude Latitude of measurement [-80,80]. Positive latitude is North latitude, negative latitude is South latitude. degrees_north int 2147483647 -80000000 to 80000000 1.0E-6 N/A
longitude Longitude of measurement. East longitude relative to Greenwich meridian. degrees_east int 2147483647 0 to 359999999 1.0E-6 N/A
mean_wave_direction Mean sea surface wave direction. degree ushort 65535 0 to 36000 0.01 N/A
mean_wave_period_t02 Sea surface wind wave mean period from model spectral density second moment. s short 32767 0 to 10000 0.01 N/A
num_pt_avg Number of native unsmoothed, beam-combined KaRIn samples averaged. 1 ushort 65535 0 to 289 1 N/A
polarization_karin H denotes co-polarized linear horizontal, V denotes co-polarized linear vertical. N/A string N/A N/A 1 N/A
rad_surface_type_flag Flag indicating the validity and type of processing applied to generate the wet troposphere correction (rad_wet_tropo_cor). A value of 0 indicates that open ocean processing is used, a value of 1 indicates coastal processing, and a value of 2 indicates that rad_wet_tropo_cor is invalid due to land contamination. N/A ubyte 255 0 to 2 1 N/A
rain_flag Flag indicates that signal is attenuated, probably from rain. N/A ubyte 255 0 to 3 1 N/A
sig0_karin Normalized radar cross section (sigma0) from KaRIn in real, linear units (not decibels). The value may be negative due to noise subtraction. The value is corrected for instrument calibration and atmospheric attenuation. Radiometer measurements provide the atmospheric attenuation (sig0_cor_atmos_rad). 1 float 9.96921E+36 -1000 to 10000000 1 N/A
sig0_karin_2 Normalized radar cross section (sigma0) from KaRIn in real, linear units (not decibels). The value may be negative due to noise subtraction. The value is corrected for instrument calibration and atmospheric attenuation. A meteorological model provides the atmospheric attenuation (sig0_cor_atmos_model). 1 float 9.96921E+36 -1000 to 10000000 1 N/A
sig0_karin_2_qual Quality flag for sigma0 from KaRIn in sig0_karin_2 variable. N/A uint 4294967295 0 to 3792125343 1 N/A
sig0_karin_qual Quality flag for sigma0 from KaRIn in sig0_karin_qual variable. N/A uint 4294967295 0 to 4060560799 1 N/A
sig0_karin_uncert 1-sigma uncertainty on sigma0 from KaRIn. 1 float 9.96921E+36 0 to 1000 1 N/A
swh_karin Significant wave height from KaRIn volumetric correlation. m ushort 65535 0 to 15000 0.001 N/A
swh_karin_qual Quality flag for significant wave height from KaRIn in swh_karin_qual variable. N/A uint 4294967295 0 to 3792059800 1 N/A
swh_karin_uncert 1-sigma uncertainty on significant wave height from KaRIn. m ushort 65535 0 to 25000 0.001 N/A
swh_model Significant wave height from model. m ushort 65535 0 to 15000 0.001 N/A
swh_nadir_altimeter Significant wave height from nadir altimeter. m ushort 65535 0 to 15000 0.001 N/A
swh_wind_speed_karin_source Bit flag that indicates the source of significant wave height information that was used to compute the wind speed estimate from KaRIn data in wind_speed_karin. N/A ubyte 255 0 to 7 1 N/A
swh_wind_speed_karin_source_2 Bit flag that indicates the source of significant wave height information that was used to compute the wind speed estimate from KaRIn data in wind_speed_karin_2. N/A ubyte 255 0 to 7 1 N/A
time Time of measurement in seconds in the UTC time scale since 1 Jan 2000 00:00:00 UTC. [tai_utc_difference] is the difference between TAI and UTC reference time (seconds) for the first measurement of the data set. If a leap second occurs within the data set, the attribute leap_second is set to the UTC time at which the leap second occurs. seconds since 2000-01-01 00:00:00.0 double N/A N/A 1 N/A
time_tai Time of measurement in seconds in the TAI time scale since 1 Jan 2000 00:00:00 TAI. This time scale contains no leap seconds. The difference (in seconds) with time in UTC is given by the attribute [time:tai_utc_difference]. seconds since 2000-01-01 00:00:00.0 double 9.9692099683869E+36 N/A 1 N/A
wind_speed_karin Wind speed from KaRIn computed from sig0_karin. m/s ushort 65535 0 to 65000 0.001 N/A
wind_speed_karin_2 Wind speed from KaRIn computed from sig0_karin_2. m/s ushort 65535 0 to 65000 0.001 N/A
wind_speed_karin_2_qual Quality flag for wind speed from KaRIn in wind_speed_karin_2 variable. N/A uint 4294967295 0 to 3792125336 1 N/A
wind_speed_karin_qual Quality flag for wind speed from KaRIn in wind_speed_karin variable. N/A uint 4294967295 0 to 4060560792 1 N/A
wind_speed_model_u Eastward component of the atmospheric model wind vector at 10 meters. m/s short 32767 -30000 to 30000 0.001 N/A
wind_speed_model_v Northward component of the atmospheric model wind vector at 10 meters. m/s short 32767 -30000 to 30000 0.001 N/A
wind_speed_rad Wind speed from radiometer measurements. m/s ushort 65535 0 to 65000 0.001 N/A
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