Sea level Anomaly and Geostrophic Currents, multi-mission, global, optimal interpolation, gridded

jebidiah.jeffery — Thu, 17 Mar 2022 15:11:17 +0000

The NOAA Laboratory for Satellite Altimetry's (LSA) sea surface height team produces 0.25-degree longitude/latitude Level-3 sea level anomaly (SLA) daily datasets by applying optimal interpolation to along-track satellite observations over the global ocean from a constellation of radar altimeter missions. Theses grids are produced with near-real time (3-5 hour latency) data. Geostrophic Currents are produced from the SLA and are included in the dataset.

jebidiah.jeffery Thu, 03/17/2022 - 11:11

The NOAA Laboratory for Satellite Altimetry (LSA) sea surface height team produces 0.25-degree longitude/latitude Level-3 sea level anomaly (SLA) daily datasets by applying optimal interpolation to along-track satellite observations over the global ocean from a constellation of radar altimeter missions. Geostrophic currents are derived from the SLA and are included in the dataset. Theses grids are produced with near-real time (NRT; 3-5 hour latency) data and a delayed-time (DT), improved accuracy, product is available for the time period 2012 to 2018.

Sea Level Anomaly Product (pictured above)

The NOAA/NESDIS Laboratory for Satellite Altimetry provides near-real time (NRT) and delayed-time (DT) gridded Level-3 sea level anomaly (SLA) products. The data are produced by applying optimal interpolation to along-track satellite observations from a constellation of radar altimeter missions. The along-track altimetry data for each of the missions are from the Radar Altimetry Database System (RADS). This product is a global ocean product with a spatial resolution of 0.25-degree longitude/latitude. The near-real time gridded SLA product is available from February 2017 through the present. Currently, Jason-3, AltiKa, Cryosat-2, Sentinel-3A, and Sentinel-3B data are used in the processing of the NRT dataset. Jason-2 was included through 1 October 2019. The NRT dataset is also part of NOAA’s OceanWatch Monitor. The delayed time SLA data are available for years 2012-2018. The DT data are of different quality than the NRT gridded SLA data. For each day, along-track data from all available missions are used and only final Geophysical Data Records (GDR)/Non-Time Critical (NTC) data are used in the processing of the DT dataset, making this product to be more accurate.

Geostrophic Currents Product

The NOAA/NESDIS Laboratory for Satellite Altimetry provides near-real time and delayed-time, zonal and meridional components of the geostrophic current. The currents are produced using the NOAA/NESDIS Laboratory for Satellite Altimetry's daily sea level anomaly grids and the conventional f-plane geostrophic current equations. At the equator, the beta-plane approximation is used. This product is a global ocean product with a spatial resolution of 0.25-degree longitude/latitude. The near-real time geostrophic currents are available from March 2019 through the present. The delayed time geostrophic currents are available for years 2012-2018. The geostrophic currents are variables within the NRT and DT SLA data files.

Figure: NOAA LSA NRT Gridded Geostrophic Currents in m s^-1 for 9 May 2019. Left is zonal component (ugos), right is meridional component (vgos). Black is land. Gray is ice or missing data.

NOTE: Jason-2 will permanently cease acquisition of scientific data at 06:48 UTC on 1 October 2019 due to aging-related issues onboard the spacecraft.

The gridded multi-mission, Sea level Anomaly and Geostrophic Currents Near-real time products will continue to include Jason-2 until October 11.
When produced, the gridded multi-mission, Sea level Anomaly and Geostrophic Currents delayed-mode products will include Jason-2 up to October 11.

Radar Altimeter Database System

The Radar Altimeter Database System (RADS) is an effort of the Department of Earth Observation and Space Systems (DEOS) at TU Delft and the NOAA Laboratory for Satellite Altimetry to establish a harmonized, validated, and cross-calibrated sea level data base from satellite altimeter.

Short Names

RADS-NRT-SLA-Daily-L4

Temporal Start Date

January 1, 2017

Product Families

Ocean Currents

Sea Surface Height

CryoSat Ground Segment, Instrument Processing Facility L1B, Products Specification Format, ESA: CS-RS-ACS-GS-5106, Issue: 6.4, April 2015. https://earth.esa.int/documents/10174/125273/CryoSat_L1_Products_Format_Specification
CryoSat Product Handbook, April 2012, https://earth.esa.int/documents/10174/125272/CryoSat_Product_Handbook
Jason-3 Product Handbook, SALP-MU-M-OP-16118-CN, edition 1.2, Feb. 2016 https://www.nodc.noaa.gov/media/pdf/jason2/j3_user_handbook.pdf
Leuliette, E. W., and R. Scharroo (2010). Integrating Jason-2 into a Multiple-Altimeter Climate Data Record. Marine Geodesy, 33(1), 504–517. doi:10.1080/01490419.2010.487795
OSTM/Jason-2 Products Handbook, CNES: SALP-MU-M-OP-15815-CN EUMETSAT : EUM/OPS-JAS/MAN/08/0041 JPL : OSTM-29-1237 : NOAA/NESDIS : Polar Series/OSTM J400, Issue: 1 rev 10, October, 2016, https://www.nodc.noaa.gov/media/pdf/jason2/j2_user_handbook.pdf
SARAL/AltiKa Products handbook, SALP-MU-M-OP-15984-CN, edition 2.5, July 2016; http://www.aviso.altimetry.fr/fileadmin/documents/data/tools/SARAL_Altika_products_handbook_01.pdf
Scharroo, R., E. Leuliette, M. Naeije, C. Martin-Puig, and N. Pires (2016), RADS Version 4: An Efficient Way to Analyse the Multi-Mission Altimeter Database, Living Planet Symposium, Proceedings of the conference held 9-13 May 2016 in Prague, Czech Republic. Edited by L. Ouwehand. ESA-SP Volume 740, ISBN: 978-92- 9221-305- 3.
Sentinel-3 User Handbook, ESA: GMES-S3OP-EOPG-TN-13-0001, Issue 1, September 2013, https://sentinel.esa.int/documents/247904/685236/Sentinel-3_User_Handbook

Measurements

Geostrophic Currents

Sea Surface Height

Processing Levels

Level 4

Spatial Coverage

Global

LSA data are distributed at no cost to the users to promote scientific utilization of the data with the stipulation that the users of the data agree to follow the policy described below:

LSA data are produced on a best effort basis.
In publications, presentations, or on web pages based on LSA data the following acknowledgment should be included.
"Altimetry data are provided by the NOAA Laboratory for Satellite Altimetry."

Latency Groups

0 Hours <= 24 Hours (NRT)

Latency Details

12 hours

Spatial Resolution Groups

2km+

Spatial Resolution Details

0.25°

Platforms

Instruments

Processing Algorithms

RADS

Data Providers

ESA

EUMETSAT

NOAA

NESDIS

STAR

LSA

Data Tool Links

CoastWatch Data Portal

CoastWatch Near Real-Time Search

Sample Filenames

1-day: rads_global_nrt_sla_20170313_20170314_000.nc

HTTPS

https://coastwatch.noaa.gov/data/pub0015/coastwatch/rads/sla/

THREDDS

https://coastwatch.noaa.gov/thredds/socd/coastwatch/catalog_coastwatch_altimetry.html

ERDDAP

https://coastwatch.noaa.gov/erddap/search/index.html?page=1&itemsPerPage=1000&searchFor=SLA

Along-track significant wave height, wind speed and sea level anomaly from multiple altimeters

jebidiah.jeffery — Thu, 17 Mar 2022 15:09:40 +0000

Along-track significant wave height, wind speed and sea level anomaly from multiple altimeters

The NOAA Laboratory for Satellite Altimetry's (LSA) sea surface height team produces 0.25-degree longitude/latitude Level-3 significant wave height, wind speed, and sea level anomaly (SLA) daily datasets by applying optimal interpolation to along-track satellite observations over the global ocean from a constellation of radar altimeter missions. Theses grids are produced with near-real time (3-5 hour latency) data.

jebidiah.jeffery Thu, 03/17/2022 - 11:09

Temporal Start Date

September 1, 2016

Temporal Coverage

Along-track data products available 09-2016 to present for Jason-3; Sentinel-3A; CryoSat-2; SARAL.

Jason-2 ended 1 Oct 2019.

Product Families

Sea Surface Height

Sea Surface Winds

Measurements

Along-track Significant Wave Height

Sea Surface Height Anomalies