JASON-2

Oceanic Heat Content, Mixed Layer Depth and Depths of 20°C and 26°C Isotherms

jebidiah.jeffery — Thu, 17 Mar 2022 15:31:14 +0000

Oceanic Heat Content, Mixed Layer Depth and Depths of 20°C and 26°C Isotherms

Oceanic Heat Content (OHC) is the measure of the integrated vertical temperature from the sea surface to the depth of the 26°C isotherm and computed from the altimeter-derived isotherm depths in the upper ocean relative to 20°C. Global 0.25 degree grids are generated daily for OHC, mixed layer depth and depths of 20°C and 26°C isotherms for 3 ocean basins: North Atlantic, North Pacific and South Pacific

jebidiah.jeffery Thu, 03/17/2022 - 11:31

Oceanic Heat Content (OHC) is the measure of the integrated vertical temperature from the sea surface to the depth of the 26°C isotherm and computed from the altimeter-derived isotherm depths in the upper ocean relative to 20°C. Satellite data inputs for sea surface temperature (SST) are from the NOAA GeoPolar Blended sea surface temperature and for the sea surface height anomaly (SSHA) are from at least 2 satellite altimetry missions. Global 0.25 degree grids are generated daily for OHC, mixed layer depth and depths of 20°C and 26°C isotherms for 3 ocean basins: North Atlantic, North Pacific and South Pacific.

BACKGROUND

More than 90% of the warming on the Earth over the past 50 years occurred in the Ocean (Shay L.K. 2019).The heat content of the ocean is the amount of heat energy (in joules) stored within a pre-defined volume of the upper ocean. To determine the heat content value in the ocean, NOAA/NESDIS produces a daily operational suite of satellite-derived Oceanic Heat Content (OHC) products for the North Atlantic, and the North and South Pacific basins. A suite of OHC products for the Indian Ocean are planned which will contribute significantly toward global coverage. OHC is an important climate change indicator and provides a high quality climatic data record. These suites of satellite-derived OHC products are validated against over one million in-situ measurements from multiple platforms to assess biases and uncertainties. The NOAA OHC product is shown to be the best product available for Hurricane Intensity Forecasting (Meyers et. al. 2015). Daily display of these OHC products provides valuable data to address key science questions related to climate such as: 1) the extent of warming (or cooling) in the warm pools of the Atlantic and Pacific Ocean basins; 2) thermodynamic processes in the equatorial wave guides associated with eastward propagating Kelvin Waves (ENSO); and linkages to the Madden-Julian Oscillation) across the tropics. Benefits for climate studies are a new understanding of the upper ocean thermodynamics, dynamics and air-sea processes relevant to tropical cyclone intensity forecasting, climatic variability (e.g., OHC anomalies over various time scales), fisheries, and coral reef bleaching. Figure 1 are the input fields (Altimetry and SST) used to generate the OHC Products.

DEFINITION

Oceanic Heat Content (OHC) is defined as the measure of the integrated vertical temperature from the sea surface to the depth of the 26°C isotherm and computed from the altimeter-derived isotherm depths in the upper ocean relative to 20°C.

METHODOLOGY

Algorithm

OHC values are estimated using four points: 1) the sea surface temperature obtained from NOAA/NESDIS Geo Polar SST Analysis; 2) the altimeter-estimates of the 20°C isotherm within a two-layer reduced gravity scheme; 3) the depth of the 26°C isotherm from a climatological relationship between the depths of the 20°C and 26°C isotherm; and 4) flexibility in estimating other isotherm depths (e.g., 25°C) then integrate. The full algorithm description is in the Algorithm Theoretical Basis Document (ATBD) (see documentation link).

Validation

Validation is accomplished by 1) calculating OHC from various in situ data sources (Argo, XBT, PIRATA/TAO, and Air-deployed probes); 2) then compared to the satellite-derived OHC grid point that is closest to that source in time and space; 3) regression analysis and root-mean-square deviation (RMSD) statistics are used to determine an agreement between the satellite and in situ data; and the accuracy has to be within 10 percent of the in situ data (kJ cm^-2).

The addition of new satellite data requires new validation of the product.

Visual images of the OHC product suite are created on a daily basis.

Short Names

Satellite derived Ocean Heat Content

Temporal Coverage

Daily

Product Families

Ocean Heat Content

ATBD: Shay, L. K., J. K. Brewster, E. Maturi, P. C.,Meyers and C. McCaskill, Algorithm Theoretical Basis Document for Satellite-dervied Oceanic Heat Content Product, Version 3.1, June 2015

Shay, L.K., G.J. Goni and P.G. Black.(2000) Effects of a warm oceanic feature on Hurricane Opal., Monthly Weather Review, 125(5), 1366-1383.
De Maria, M. , M. Mainelli , L.K. Shay, J.A. Knaff, and J. Kaplan. (2005) Further improvements to the statistical hurricane intensity prediction scheme (SHIPS). Weather and Forecasting, 20(4), 531-543.
Ali, M. M., P.S.V. Jagadeesh and Sarika Jain (2007a). Effects of Eddies on Bay of Bengal Cyclone Intensity, EOS, Vol. 88, p 93, 95.
Halliwell GR, Shay LK, Jacob SD, Smedstad OM, Uhlhorn EW (2008) Improving Ocean Model Initialization for Coupled Tropical Cyclone Forecast Models Using GODAE Nowcasts. Monthly Weather Review, 136(7): 2576-2591.
Mainelli M, De Maria M, Shay LK, Goni G (2008) Application of Oceanic Heat Content Estimation to Operational Forecasting of Recent Atlantic Category 5 Hurricanes. Weather and Forecasting 23(1): 3-16.
Shay LK and Uhlhorn EW (2008) Loop Current Response to Hurricanes Isidore and Lili. Monthly Weather Review 136(9): 3248
Jaimes, B. and L. K. Shay. (2009) Mixed layer cooling in mesoscale eddies during Katrina and Rita. Monthly Weather Review. 137(12), 4188-4207.
Hallliwell, G., L. K. Shay, J. Brewster, and W. Teague, (2011) Evaluation and sensitivity analysis of an ocean model to hurricane Ivan in the northern Gulf of Mexico. Monthly Weather Review. 139(3), 921-945.
Shay, L. K., and J. Brewster (2010). Eastern Pacific oceanic heat content estimation for hurricane forecasting. Monthly Weather Review . 138, 2110-2131.
Shay, L. K., P. C. Meyers and J. K. Brewster, (2012) Development and analysis of the Systematically Merged Atlantic Region Temperature and Salinity (SMARTS) climatology for ocean heat content estimates. J. Atmos and Oceanogr. Tech. (In Preparation)
Meyers, P. C., L. K. Shay, and J. K. Brewster, (2013) Development and analysis of the Systematically Merged Atlantic Region Temperature and Salinity (SMARTS) climatology for ocean heat content estimates. J. Atmos and Oceanogr. Tech. (Submitted)

Measurements

Depth of 20° and 26° Isotherms

Ocean Heat Content

Ocean Mixed-Layer Depth

Sea Surface Height Anomalies

Sea Surface Temperature - Geostationary

Sea Surface Temperature - Polar-orbiting

Processing Levels

Level 4

Spatial Coverage

Global

Latency Groups

24+ hours (Delayed)

Latency Details

~36 h

Spatial Resolution Groups

2km+

Spatial Resolution Details

0.25 degree gridded

Platforms

Instruments

Data Providers

NOAA

NESDIS

OSPO

Data Tool Links

CoastWatch Tools

CoastWatch Data Portal

OSPO Tools

Satellite Ocean Heat Content Suite

Sample Filenames

ohc_naQG3_2012_215.nc, ohc_npQG3_2012_215.nc, ohc_spQG3_2012_215.nc

HTTPS

https://coastwatch.noaa.gov/pub/socd2/coastwatch/ocean_heat

THREDDS

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

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

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

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

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