to provide operational users and the science community ......–operational oceanography •sst...

Committee on Earth Observation Satellites

Sea Surface Temperature Virtual

Constellation

To provide operational users and the science community with the SST measured by the satellite constellation

Operational exploitation of sea-surface temperature data retrieved from

satellites

Anne O’Carroll, Gary Corlett -EUMETSAT

Kenneth S. Casey - NOAA / NCEI

Group for High Resolution Sea Surface Temperature Committee on Earth Observation Satellites


Constellation

http://www.ghrsst.org

Why is SST important?

• SST influences atmospheric circulation– NWP boundary condition

• SST influences density and circulation of oceans– Operational oceanography

• SST changes can impact ocean biogeochemistry– Impact on fishing

• SST is an indicator of climate change– Improving seasonal prediction



Constellation


What is SST?

SSTfnd sea surface foundation

temperature

SSTskin sea surface skin

temperatureSSTsubskin sea surface subskin

temperatureSSTdepth sea water temperature at depth z, e.g.,SST2m

SSTint interface sea surface

temperature

Dep

th

10μ

m1 mm

1 m

10 m

SST – SST10m (K)

0 0.5 1.0 1.5 2.0 2.5 3.0

Nig

ht-

tim

e,

or

stro

ng w

inds



Constellation


• GHRSST, the Group for High Resolution Sea Surface Temperature grew out of a Pilot Project of the Global Ocean Data Assimilation Experiment (GODAE), 1997-2008.

• Composed of an international Science Team of researchers and operational practitioners.

• Coordinates research and operational developments in satellite-derived SST.

• Organized into Technical Advisory Groups and Task Teams focused on particular problems or activities.

• Data processing through Regional and Global Data Assembly Centers, combining satellite and NWP fields in common data formats for ease of access and analysis.

• Data are available in perpetuity at the GHRSST Long Term Stewardship and Reanalysis Facility at the NOAA National Centers for Environmental Information (NCEI).

What is GHRSST?



Constellation


Patrons and Sponsors

Copernicus Marine Environment Monitoring Service

http://www.osi-saf.org/

http://www.eumetsat.int/website/home/index.html

https://www.godae-oceanview.org/

http://wwz.ifremer.fr/institut_eng

http://imos.org.au/about.html

http://www.jaxa.jp/index_e.html

http://www.jma.go.jp/jma/indexe.html

http://www.metoffice.gov.uk/

http://www.noaa.gov/

http://www.remss.com/

http://www.stfc.ac.uk/ralspace/default.aspx

http://www.bom.gov.au/

http://www.ceos.org/

http://www.reading.ac.uk/

http://www.rsmas.miami.edu/

http://ww2.uri.edu/

http://www.esa.int/ESA

http://ecmwf.int/

http://www.nasa.gov/

http://www.navy.mil/

http://www.nceo.ac.uk/



Constellation


User requirements for high resolution sea surface temperature data products and services from operational, scientific and climate communities

GHRSST Project Office

GHRSST Advisory Council

International GHRSST Science Team

User, Data and Services

Technical Advisory Group

(UDS-TAG)

Estimation and ValidationTechnical

Advisory Group

(EV-TAG)

Analysis and Intercomparison


(AI-TAG)

Climate Data Records


(CDR-TAG)

CEOS-SIT

CEOS SST Virtual

Constellation (SST-VC)

GHRSST Science Team



Constellation


CEOS SST-VC



Constellation


• GHRSST sources users requirements from many communities, including, for example:– The WMO Rolling Requirements Review– GODAE Ocean View and JCOMM ETOOFS (Expert Team on Operational

Ocean Forecasting Systems)– WMO GCOS (The Global Climate Observing System)– OOPC (The Ocean Observing System Development Panel of The Global

Ocean Observing System)– Internal GHRSST Science Team members

• GHRSST then synthesises these requirements into a common set of:– Measurement requirements for both space based and surface based

instrumentation• Includes a gap analyses and list of priorities

– Scientific and technical challenges for ongoing R&D elements• Drives the program of the technical advisory groups and task teams

GHRSST is driven by user requirements



Constellation


Regional/Global Task Sharing

NOAA National Centers for Environmental Information

Regional Data Assembly Centers (RDACs)• Create GHRSST-compliant data• Some are “self-serve” but most

provide their data to the…

Global Data Assembly Centers (GDACs)• Aggregate and serve data in near

real time• Serve data for first 30 days then

provides data to..

Long Term Stewardship and Reanalysis Facility (LTSRF)• Archives and serves data for the

long-term, starting 30 days after observation for most data



Constellation


GHRSST Data Specification (GDS)

• All GHRSST data conform to a common specification• GHRSST Data Processing Specification (GDS) 2.0r5

• All data files are in NetCDF4 (“classic”) file format

• All data files contain Climate Forecast (CF, v1.6) and Attribute Convention for Dataset Discovery (ACDD, v1.3) compliant file level metadata

• All GHRSST data products have a ISO 19115-2 compliant metadata record

• All data are free and openly available to everyone

• Some RDACs require simple registration



Constellation


GHRSST Data Processing Levels

LevelGHRSST

CodeDescription

Level 0 L0Unprocessed instrument and payload data at full resolution. GHRSST does not make

recommendations regarding formats or content for data at this processing level.

Level 1A L1A

Reconstructed unprocessed instrument data at full resolution, time referenced, and annotated

with ancillary information, including radiometric and geometric calibration coefficients and geo-

referencing parameters, computed and appended, but not applied, to L0 data. GHRSST does

not make recommendations regarding formats or content for data at this processing level.

Level 1B L1BLevel 1A data that have been processed to sensor units. GHRSST does not currently make

recommendations regarding formats or content for L1B data.

Level 2

Pre-

processed

L2P

Geophysical variables derived from Level 1 source data at the same resolution and location as

the Level 1 data, typically in a satellite projection with geographic information. These data form

the fundamental basis for higher-level GHRSST products and require ancillary data and

uncertainty estimates.

Level 3

L3U

L3C

L3S

Level 2 variables mapped on a defined grid with reduced requirements for ancillary data.

Uncertainty estimates are still mandatory. Three types of L3 products are defined:

∙ Un-collated (L3U): L2 data granules remapped to a space grid without combining any

observations from overlapping orbits

∙ Collated (L3C): observations combined from a single instrument into a space-time grid

∙ Super-collated (L3S): observations combined from multiple instruments into a space-time

grid.

Note that L3 GHRSST products do not use analysis or interpolation procedures to fill gaps

where no observations are available.

Level 4 L4

Data sets created from the analysis of lower level data that result in gridded, gap-free products.

SST data generated from multiple sources of satellite data using optimal interpolation are an

example of L4 GHRSST products. GMPE products are a type of L4 dataset.



Constellation


• Real time– For individual products, can go direct to relevant RDAC– For wide range of products, use the Global Data Assembly Centre (GDAC)

• Primary system at NASA JPL: http://podaac.jpl.nasa.gov/• Secondary system at Ifremer: http://cersat.ifremer.fr/data/collections/ghrsst

– Requires simple registration– Not all datasets are mirrored

• Delayed mode (30 days after observation)– LTSRF hosted by NOAA NCEI: https://ghrsst.nodc.noaa.gov– Many NOAA GHRSST products available in near real time

• All have many ways to access GHRSST data– FTP, HTTPS, DAP, WMS, WCS, Live Access Server, discovery services at collection

and granule level such as Geoportal REST API, CSW, OpenSearch, HiTide, PO.DAAC Web Services, State of the Ocean

• Any issues please contact the GHRSST Project Office ([email protected])

GDAC and LTSRF Access Services

http://podaac.jpl.nasa.gov/

http://cersat.ifremer.fr/data/collections/ghrsst

https://ghrsst.nodc.noaa.gov/

mailto:[email protected]



Constellation


The future: Evolution of R/GTS



Constellation


Strengths and positives of GHRSST

Are the products adequate?

• The “future of GHRSST” recently discussed this topic at the science team meeting

• Excellent interaction between space agencies, researchers and operational services- Activity: Continue regular ST meetings

• Take advantage of new technologies and new observations to facilitate improved products for users- Activity: Develop open source consistent methodologies for all sensors



Constellation


Remaining challenges

What would we like to see done differently?

• Further scientific advancement needed in some areas to keep up with technology and communicate more effectively with external parties– Activity: Evolve our communication methods

• Long-term continuity of people, observations and services.– Activity: Introduce a mentoring program for early career

scientists in Task Teams



Constellation


Next steps

• Evolve the GHRSST Regional and Task Sharing Framework

– Implementation of pilot project

– Recognise new GHRSST Data Assembly Centres

– More defined sharing of data management resources

– Maintain a central catalogue of all GHRSST datasets

• Further engagement with more countries (already India, China, Korea participating) and towards full global constellation of GHRSST compliant SST

• User interaction and engagement (e.g. steps towards increasing interactions with coral reef communities and other intermediate users).

• Scientific advancement centered on specific Task Team objectives (including: cloud-screening; uncertainties; spatial precision; high-latitudes; climatologies)



Constellation


Summary

• GHRSST mission: To enable satellite-derived global SSTs with good estimates of uncertainty to operational users and the science community

• GHRSST is a Science Team of operational practitioners and researchers

• The provision of SST data through GHRSST has grown to a mature sustainable essential service

• GHRSST enables a wide range of user driven SST-related products and services

• The SST constellation is not optimal and always changing

• GHRSST is an example of effective international cooperation

to provide operational users and the science community ......–operational oceanography •sst...

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